Tài liệu the technology of making cheese from camel milk camelus dromedarius ppt

bas heen clearly demons th restricted drinking-water eaused an inerese in water ceperiments shih content and a subsequent decrease in total sols Yagil and Brion, 1980; Yagil, 1986: Yagi

The technology of making

cheese from camel milk

(Camelus dromedarius) 113

The technology of making anna

cheese from camel milk AND HEALTH

PAPER

by

J.-P Ramet

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'ĐÁo son,

Contents

Ghamert

‘The importance of the camel in ard regions 1

‘Camel milk production 2

‘Composition of camel mile 3

‘General composition 3 Tiemain constants $ Summary of cheese and butter technology 4

‘Cheese making eernology 4 The lechnology [the man sheese vaisle= :

‘Summary of butler making technology 8

Produets obtained from whey 1 Thay chegss 1s

Chapter 3

WAYS OF IMPROVING CHEESE MADE FROM CAMEL MILK 17

‘Selection of high-grade mil HÀ Seqregaton of abnormal rik 17 Microbial quatty 7 Milk preparation 18 Heat veatment 38

Increasing the ceting tempers.re

Increasing the amount of mikcloting enayine

Basic mix processing parameters

Prepating ad using lets starters

Tắc gas mang cac cae mi

‘THE IMPORTANCE OF THE CAMEL IN ARID

REGIONS

‘The image ofthe camel, symbol of human survival in

the deven is tsd to te history ofthe major nomadic

etilizaions of the hot dry aeas of the nome

hemisphere The came embehes on of the esentiat

elements ofthe culture and agriculture ofthese

Geographically, the camel is distributed thoughout

the topical and subtropical dry zones of North Aiea,

‘este Asia and nothwest India Figure 1), Th limits

fof its natural ditbution are determined by wet

climates and the presence ofthe sets ly Camels were

‘troduced into Ausalivona large sale daring the last

entry lated intraductons ton place in pas ofthe

United States of America, Central America, the

Caritas, southern fica and Europe (Wilkon, 1984;

Wilson, Araya and Melaku, 1999)

The camel is the ical domestic animal in deserts

ith Fong dy, hot

scarce, atic annual rainfalls betscen 50 and 350 mm

The camel is used for several purposes for whichis

role is esti, It 9 used as a Beast of hunden for

teanspomting goods ard peop

rik Milk often the only regular feed source toe its

eight months or more and

aswel as for proving

‘owners The camel's meal, wool and eater are also

‘widely utilized In some parts of East Altea the una

‘is bled regularly and its blood consumed fresh or mined

with ilk The camel is univesily highly valued an

provides socal standing for is owner

“The che rele of the camsl nlates đinh dỡ

remarkable adaptation 1 extremly harsh conditions I

can flourish where no ether domestic asimsl can

survive, This exceptional bility i theres of several

anatomical and physiological characteristics Whe

green forage is available in rill emates, the eseme

‘ay go several months without drinking Under very

‘hat senditions,it may dink only every eight ten days

and lose up to 30 percent of is body weight through

dehsdadien (Yagil und Etzion, 1980: Yagil, 1982,

ison, 1984; Yagil, 1985: Ramet, 1987),

This remarkable atrbute results From a very low

basal metabolism and seve

adaptations Water {water conserving

respiration and

ay 0 radiation when the animal is at fest @¢ when the onosphere cools dovin at nigh, Moreover, the water lost by respiration and perspiration is fow compared with the body weight of the animal, Wate loss inthe faces and ine #8 also very Tinied (Wilson, 1984; Yagil 1986), The morphology of the animal, haracterized by the length ofthe neck and limbs ane

hy the conical shape of the abdomen,

ses a large General thermal conductivity aso appears to be enhanced by

surace area that improves heat wanster the location of ftty Hes Ue ham (Wilson, 198 Yagil 1986

Anosber limitation imposed by arid conditions ithe spare and poor qusliy of pastures, Compsred With

‘other ruins the camel is distinguished by the igh isersiy of ils det, Ica Food on hernaceous plans shrobs, shouts, cacti and date tones, During the dey

Season, it offen has to survive on thom withered Pants Tove in protein bot rich i fibre and cellulose {Poyre de Fabeogues, 1989), Acconling te the litle research on the subject, it appears that the camel assimilates iogen and cellase ber than any ober mammal (CIHEAM, 1988; Kamoun, Girard and erga, 1989; Gérant and Richard, 1989),

“Thishigheificiency im assimilating clluloxe appears

to be wlited to a specific mastication process that induces improved impregnation of saliva into the bos, The location of aquiterons eels om the somach all permits beter wetting of feed during rumination and impooves intake of some soluble elements In

males elements pass

camels have a distinctive kidney singers that

‘considerably rues the removal of ure in urine The

removal of blood urea is effected by selective

pemacabilty ofthe stomach and intestinal walls Las,

this urea is assimilated by the stomaeh miroir i the

cavities 10 ensure protein symhesis (Wilson, 1984;

Yagil Saran and Eizion, 1084; Vail, 1985)

In 1985, the weld camel population was estimated

at about 16.5 million with more than 80 percent of the

‘wor herd in Aries, Somali and the Sudan hve the

largest populations, with some 70 percent of the

Aican herd n Asia, about 70 percent ae spread over

the Indian subcontinent (Wikon, Araya and Maku,

1090)

“`

to tack because of lack of reliable data ft appeass,

however that a decrease in numbers was observed

from 1950 to L980, Several eaunes were responsible

including mechanization of riper, sedemarizaion

(of nomads and exceptional droughts Over the last

decade, withthe exception of afew isolated cases

‘pew phase in the development of the camel ean be

noted (Table 1), This isthe cesalt of several factors

mainly an increasing demand for milk and meat as 8

cconsequenee of lage human population ineeases in

the areas involved, Othe factors ae assoc with the

extension of the desert in the Sahel region and

increased ization of camels as pack snd work

imal in countses where the cost of fv i igh A

Further weason for this resurgence is he effect of recent

technical and scientific eseareh (Wikon Araya and

Metaku, 1990: Farah, 1998) This work hes shown that

the camel is the most efficient domestic animal for

converting vegetative mater into Work, milk ad meat

in hoc ard areas, Recent advances in understanaing

camel pathology and physiology” in elation 10 ts

‘reluts hae led 0 beter understanding of beading

and processing methods (Howe, Peyre de Fabregucs

and Richard, 1985: Higgins, 1986; Mare, 1987, OIE,

1987: IEMVT, 1989; CIHEAM 1989; Wilson, Arya

and Melakn, 1999 Farah, 1993),

‘CAMEL MILK PRODUCTION

Existing data onthe milk yield of camels are numerous

hut highly variable, Acconding to results fom several

author, lactation perieds vary from 9 to 18 months

with anal milk yiclds of between 800 and 3 600

liges Mean daily ik paduction is reported to range

from 2 106 lives under dosert conditions an up © 12

1 20 fives under mote intensive breeding systems,

“These lange differences can be explained by the Fact that measurements ave often been me unde lal conditions withoot taking into account local ostors that might influence milk production Furthermore, camel breeds or individeal animals probably exist with significantly different milk-peodicing potential that has net been Tally exploited because the selective Jessie of humans on the eamel has been mini

‘compared with other domestie animals (Richard and eran, 1989),

"` ` Diets enticed with gteen forages such as alll bpersim of cabbage preatly inetease milk yield (Koes, 1977; Knoess et al, 1986; Richard and Gerad, 1989), The amount of milk is only marginally

sử when drinking-water is restricted, while {oral solids are sigiticanly lowered (Yagil and Euien, 1980: Yagi, Saran and Exon, 1984: Ramses Lost: anh, 1993), This milk dilution isa

‘Physiological response to hel and could be a natural

‘adaption to provide much-needed water 10 the hydrated cal (Yagil, Saran and zion, 1984; Farah 1993),

Studies conceming the development of silk quantity as « function of stage of station indicate Title comelaion Lactation curves in fact indicate

huge differences compared sth other lactating

‘mammals, Some curves indicat low yields during the Fist half ofthe Itation peviod anda inctease in the second, Other Fesuis report lhgher yields at the beginning, followed by falls towards the end

‘one of 0 distinc poaks can be

‘observed of comerel steady production shousbout the lctation (Field, 1979, Bachmann and Sehulbs, F987: Ellouze and Kamoun, 1989; Richard and Goeant, 1989; Martinez, 1989) The high disparity

ous sets of data can probably be

‘plained by differences in genetic poten lint, Feeding conditions and sampling techniques

Milking practice also affets the amount of ilk Gonerlly, the call is allowed 10 suckle for a To

‘Occasional,

between these

minutes bore hand milking The actual volume of

sie IF mÌk xeerled is therefore difficult to me:

miking is

‘mechanical stnlation of the mammacy gland, lower Yields are observed, Milking must be dane by a Ferson who is well known tothe cansel, When the usual mike is changed significant milk retention i often observed Kt also appeats that milking frequency influences daily milk yold Generally animals ate

performed without any

‘hese of mating cheese fro camel i

snitked two to four tmes a day (Harley, 1980: Ramet,

1987; Martinez, 1989; Abeidertshmane, 1994) but

sometimes as many’ as six oF seven times (Knoess

1977) Changing dhe milking frequency Team tao to

foar operations ineeased milk produstion from one to

[LS lites a day (Evans and Pooys, 1980)

‘COMPOSITION OF CAMEL MILK

General composition

Publications dealing with the composition of camel

silk erelatively scare and met ofthe information|

is approximate and fragmentary, Table 2 thertone

‘more important data published in review articles by several authors (Yagil, 1982;

Wilson, 1984: Wilson, Araya and Mebko, 1990;

Farah, 1993), More regent results Have ben ded,

Table 2 shows a farly wide range of values for the

indicates oly

‘main constituents of camel mils As mentioned above

for milk old, this diversity could be main olted

to the different genetic potential of breeds, fo varying

physiological snd Feeding conditions oF to sage of

action, The computed mea value idieates tha t

total solids content of camel milk is slightly lower

han 60s ih,

“The most important ctor affecting the overall

composition of camel milk i water coment, I bas

heen clearly demons th

restricted drinking-water eaused an inerese in water ceperiments shih

content and a subsequent decrease in total sols

(Yagil and Brion, 1980; Yagil, 1986: Yagil, Amit

Aba-Ribaya and Elvion, 1986), Seasonal climatic

vrarations and water and feed availabilty id w

1986: Ramet, 1987

Simla effect (Kaoess et a

Ramet, 19948)

‘The main constituents

Although the over of eae milk is

similar © cow's milk, some dferences exist im the

‘molecular composition of proteins and lps and in

(he minora lance,

Protein, The average mean compesiton of the protein

vel milk are generally Similar to those of co's mil, The average values for

the casein and whey protein contents vary frem 19 19

23 percent and 0.7 to 10 percent respectively The

trogen content of casein is litle lower than cow's

nifk aching 71 10 79 percent of wipro rtrogen

compared with 77 ta 82 percent Jenness and Sloan

Larson-Raniiewicz and Mohamed 1986; Farah and Rosse 1959: Mohamed 1990: Farah, 1993)

‘he sate ofthe eascin micelle srutare has seldom

uc investigated, Most rests however, conchae tha

‘he size disteibution of ease particles in camel mi is signticantly broader han in 600s milk, exhib reaer numberof large panicles The average micelle ameter of camel milk was found to be about double

‘hat ot es milk at 320 nm and 160 am respectively (Table ts Sawaya of al, 1984: Larsson-Raanikiewie

‘and Mohamed, 1986; Far an Ruegg, 1989: Jarl

‘and Ramet, 1991; Janda, 1993),

“The quantity of whey proteins is higher in eam milk han cows mil, 81.09 tL pescent and 07 20

‘08 pewcent espectively vl Factions have heen ilemiied

clectrophoretie mobility anal tote primary sequen

according 10 chromatographic and

of

“Two types of aipha-

their amino eid chains Facalbmin similar to bovine mi Have been isolated Betiloetoglohulin has not ees cleasly identified (Conti et a, 1985; Beg eta, 1987; Farah, 1986)-Two novel camel whey proteins, unlike any’ known bewine milk whey have been separated and characterized (Beg eta, 1987), The heat stabilay of

lk whey proteins was found we considerably

(Fara 1986; Farah and

‘he variability is higher wih extreme Wales ete

290119580 percent in camel mk compared with 4.40

to 580 percent in cov’ mith (Webb, Johnson and Alford 1974)

Table 2 indicates thatthe aera

Lipids A bibliographic review indeates thatthe at content of easel ik varies greatly from 1.10 0 $80 den depending onthe breed and ceding conditions, the average being the same as for cow's milk Table 2),

Shudies on the sinvcture and composition of fat

lobules revealed two main characters:

* Whereas previous sesuls have Found small fat

parce in camel milk (Gouds, EL-Zahat and El

Shabwavy 1984: Kooesse af, 1986), move recent

work micas that fat globule size distebutin is

simlar to cow's milk, with an average of 2.9

micrometres (Wahda ea, 1988; Fạnh and

Rucgg, 1991: Farah, 1993} The fat globule

membrane appt tobe thicker than in othe types

‘of milk and closely bound to the proveins (Rao,

up and Dasts, 1970 Knoess of al, 1946

Farah, Sirf? and Bachmann, 1990; Farah and

Rusgg, 1991), The eweaming properties of came!

milk fat globules are poor, resulting from a

efieieney sn agglutinin that cases a very slows

rate at all temperatures (Farah and Ruegg 1991)

A factor spoil

potcentage of short-chain C4 t0 C12 fay acids

The concentration of long-chain faty acs such as

palmitic and stearic are however, rlaively high

{Table 6) As a consequence, the phy’

propenies of the triglycerides are characterized by

mmích higher acting and erystalization points

1089; Farah, Self and Bachmann 1989; Farah

sind Roeps, 1991: Ahu-Laihi, 199),

Minerals Table 7 indivates the mineral content of

ail milk of varios origins as mise by sever

authors The show that the

soeentnlionx of the major salts are slightly lower

than cs il,

1 appcars that the salt halinee hetsszn the soluble

andthe colloidal forms of calcium, phosphors and

‘magnesium i sey similar to that measured ia cow's

nil, The percentage of the soluble Trations wwaches

nd Ro 1989), It also seems thatthe proportion of soluble

30 percent of the toa content (Farah ä

alii and phosphorus inereases up 10 GT and 75

percent respectively when milk is collected inthe hot

Season from animals managed along traditional

extensive lines

Vitamins ‘The sitamin content of camel milk differs

Arm cow's silk in that i nclades higher level of

viumin Cand niacin (Table 81, Conversely the

amsount of vitamin is much lower, varying hotween

129 BLN g (Ahmed, Aviad and Fay, 179) and

50.0 TNO g (Sawaya ef al, incomplete informati i avaiable on the vitamin 1984), Because enly content of cael mil, the figures mentioned above should be teated with caution,

SUNIMARY OF CHEESE AND BUTTER TECHNOLOGY cheese-making technology

General principles, Mik isa biological substance that

is panoularty suscepible to degradation through the action of microbes an enzymes This ination mainty sais from its complex composition, where spoilage fonganiss can fit large variety of nutrients, The high water content ant neutral pH also facia

‘nestle cha Cheese-making mology aims to preserve milk 0 tha conssmption can be posioned for pesos For 3 Few days 10 several months, The preservation of the oducts obtained mainty throug lacie acitiaton

aration These operations take place

‘ring the so frst steps of processing, the setting coagulation) and dnining phases Por many cheese types third phase knows as rpening then takes place

“This induces changes in the cosgulum, separated

Cased by complex microbial nd

Tn cheese mabing, contol of the preservation process allows these changes 0 be manipoated in

"` sinet physicalchenical ann mirobial composition and sensory character

be divided into fur main satepories depending oa the

‘iellar stale of mi casein Ih practice igi

besa si i effected by to methods

action, using mill-cowing enzynes such anne

+ by enmentaion, bacteria andor inoculated cic Marts

‘The mechanisms of the clotting methods ate

-ompetely diferent but both lead to the Faron of

cogaaldm called a cusd of clot, The physical and

theological properties af the cued depend on the

lowing method used (Table 9,

Intypieal cheese making, the two methods ate never

‘sed separately bat he balance af each is well defined

for a pamicuhir choese variaty The different cheese

categories can he identified on this hass 2 Follows

+ fos chooses procesa manly with Loti sting

‘semi-hard and hard cheeses processed mainly by

exzymic coin:

+ sft chooses proces hy halancing the swaths

Draining

The re cougulam s physically unstable, which leads

toa progressive and spontaneous septation ofthe cand

and whey This development is charter hy

sepiegation of the sifferent components of the milk

solids Most of the water aid lactose and) small

Fraction ofthe fa and preein accumulate i

Most of the protein and fat are pros

oncenied ints the cheesv cunt acorn

te the

methol usdlto dnin te khi

Tm akon toss clotting effet, the acidification

process plays a hey role in climinaing the colloidal

‘minors of the casein micelles The final solubility

level of calcium and plosphonis determines «he

draining rate of the cunt and, in tum, the texture and

total solids content ofthe che

Th

sim lo de

processing pastes fr each Ie oF cheese

op the curd and, at the same me,

acidity profile which induces s specie avidity levet

land physial-chemisal composition Typical acy

eselepiment profiles sist be followed daring the

sing proces in order to prac ferent waeties

soccesflly, This neludes the need 19 know the

strength of the late seid actin ano understand

and contol the development of lacie states

Ripening

AL the end of draining, the composition volume and

shape ofthe curd are ell defined A ths slag, mest

cheese varieties replaced in sipening rooms, The

Purpose ofthis final processing phase i to mei and

improve the appearance composition texture, favour

und tive vals of the cheese

‘roma chemival standpoint, npening comesponals to

ni of the curd in which

an enzymic develope

proeolysis and lipolysis ae mainly domi Casein

is hydrolysed during ripe molecule ing imo fractions of tow

polypeptides, peptides, amino acids and ammonia, The fats ess modified in the marty fof cheeses but, consersety, more hydrolyse in some blue types of soft cheeses, As a result, fay acids, glyeerl, aldehydes and Ketones are liberated and sscumulated in exch ype of chee

'ypica profile, Prowolysis and lipolysis ane eased by: numerous

according 103)

enaymes of varios origin: endogenous ilk enzymes, the cesidual aetiity oF milky cloning enzymes nicrabial enzymes prod ed by moulds and bacteria

til yeas growing imo oF on the suroeeof te cheese

‘THis last category is ominane in cheese varieties Fipened ly hese microflora For cheese without external of internal flor, hydrolysis much lower

“The epsimam pH forthe enzymes is generally ne seutral (pH 7.0, Atte end of caining the csese

‘round 45 vo 52 đepehMiag on the varity, is too low

‘and unsuitable for optimal development Ks thus

iy in pratice to increase the pH, which mas be đone as follows:

mí hanl and hued chooses, neutralization

‘curs esl oF a large amount of minerals

remaining inthe co

‘or soft cheeses and some semi-hanl cheeses, he

pi incsene Í fected hy sposfie miroflra that assimilate lati aid

The choose ripening specific 10 each che

processes are complicated und

rom a practical siandpoint, ever factors such as regulation roam

imate Cemperature, humiciy, air Row), time and unig (Wuming and cleaning) are used 4 obtain a standand predict in accordance with the nga

"1.1

‘Tne technology of the main choose varieties Fresh (cottage) cheese, Fresh

isinguishod y various techoologeal characteristics

its indivi eharacter

Congstation Coagulation dar acid in charetee fresh etcesepretin is mtaly The choeemker seinfinces the pronkiton of lactic acid first by moenling the mie

ty 30 lites fees) and by adjusting dhe rik temperate for optimum growth (38 19 27°C), Second, he activity fof the mailceloing enzyme is ited by the use of

vith measured amounts of etic laters (0

‘ety low amounts (1 to 5m fees) and by setting

‘the temperature as far as possible fromthe opt,

Conseguenlly, the progress of coagulation depends

closely on acidity development and the subsequent

decrease of pH This development is quite slow The

lowing time varies fom 6 0 1S hours an the custing

tine increases to around 16 40 48 hours, This kong

scggulaon tne encourages fat creaming when fll or

—¬ ` vod this,

the use of homogenized or skimmed milk ss

recommen

A the end of the coagulation period the acidity is

high (0.65 to 1.00 percent) se pH value is lowe (pH

04.8) and the curd takes om is paticular theologieal

Properties, such as high firmness and britleness and

00d whey peeteabiliy

Danning

“The ability’ of acid un wo Un fs extemal lini,

“Thoin choose solids content ith generally les than

30 percent, with arange btacen L2 and 22 percent

Spontaneous syneresis remains slow and weak

oF the high demiaeralization of the casein

‘micelles and subsequen! Tow cud elasticity, To aban

reasonable wheying-of times and Wel drain ehees,

ft isoften necessary in practice to apply some physical

tnsatments tothe cond, which mist alvays be carried

ut carefully hecase the curds rate

Ín tritional processing these treatments consist of

ting pressing and mising the curd, The prosess

takes place while mowlding the cot in draining bags or

hoops ard daring ting, The cual drsining peri

Tass for 24 10 36 hours at com temperature 20 10

30°C With modem centnifigal processing techniqus,

Femoval of whey occurs instantaneously jn thế

separation This harsher mechanic treatment requires

Firmer curd, achieved hy increasing the amount of

losting en2yme ad the temperature of senneting

Atte end of draining, the cheese is characteris

by 2 fow dey-muater content aa foe pH values an

mineralization (0.1 pescentcalvinm and 0.2 percent

phosphorus) AS n rei, the chese lacks cohesion

and looks like soft watery paste For (unher

reservation the product nist be packaged ilo rigid

Aight cups in onder fo prevent wheying off and

eslemal contamination

Consumption of fresh cheese generally occuts

without pening immediately afte draining, The basic

ci taste cane modified hy aling lange sarily’ of

¬ spies or jams

Shelf 4 limited to a few days under eesrigorated

‘conditions (194°C) bat can be increase by applying

Dain Soft

‘in acconlance with the theological behaviour of the

se drained using mild mechanical wetment lat, These conditions ld athe formation ofa chaos

Wand resid

‘mineral content (0.2 660.8 percent clesum) an alow

pl (47 10.49), The cư is of average cohesiveness The size and weight ofthe chee

of average soils content (5 1055 pt

Ripening Ripening of soft cheese is fac nape wo 40 eight weeks) depending on the water content and the osotftenee of microflora with high eneyanic activity

growing on the sarfice or imie the choess, On the tras of the dominant type of ripening organism, three soft cheese categories may be distinguished

soft cheeses with, sree moulds: Peneltians eamender

‘soft cheeses with sahee bacterial fons: Bresibacterinn inns:

‘soft cheeses with intemal moulds oguefor Peniciltiaas Semi-hard and hard cheese, Toe process

heo cheeisddinelby the fdllasing chưnyleriie Cangulalon

‘The main enzyme coagulation seton is obtained by using high concentrations of elting enzymes (2010 40

‘300 Tives) and hy adiasting the temperature 10 a level which is madera for enzyme setiviy 2 AIC) For the same reason, laste aid developinen reimsins sery hinted Unogh the ase of Tow inital amoum of mesophilic anor thermophiie bactesia

10516 100 ties,

ofan hes fn cat te

Under ese coniton, clotting time is shor (100

30 minaes) The urd possesses the spiel properties

of an enzymic go good easel low britkeness and

high synresi ability, al of whic ae diet induced

by high casein mineralization,

Draining

Drainage of the curd is fast and thorough, The high

solids content (45 40 70 percent, is reached by

applying physical weatments sich as euting, sting

washing cooking and pressing, These actions ave

improved by moderate patel acd development of the

utd, This development i atm at obtaining high curd

‘mineralization (1-2 to 18 percent cfeiun) ana larpe

cheese The pH value atthe end of draining anges

from 3.010 82

Draining takes fom 20 0 48 hours, with the greater

prof the whey running of during the frst ee hours

The final pressing is carried out manly to compact the

cod grains ater than to luee lunber dnn

Ripening

“The process of chỉ ripening is conditioned by

vation determined mainly by the imtererion hotween lactic acid and ealeams Tn some

cheeses, complementary neutralization takes place

‘through development of mierofleron the sure,

saft cheeses,

These erations induce progressive neatalization

and subsequent protein and fat breakdown ia tie cheese

Aang Uke varios sources of enzymes involved in

Fineing the elating proteases and those of ica

‘origin are most svosed.For some hand cheese types

(Gmyề and Emmemthal,

specific propionic Fermentation develops during the second part of the

"pening pie, posiding the types olex ad avour

“The average ripening time is three weeks six

montis under factory conditions and ca extend 19 610

12 mosh for aditionalprxetion acsoeding to dry

‘matter content, The remperatre ofthe epening roams

's normally between 12 and 14°C, When propionic

fermentation i required, the temperature is nereaned

to about 20°C daring the lator pat of ripening

"` "

cheese surface in order to regulate growth of certain

microbial ors oe 0 inkibit adverse gsowth on products

‘with dey cous or nists,

Cheeses made from hes Whey gonerilly eowtins

Significant amounts of whey proteins 10.78 1 09S

percent, which consist largely of lactalbumin nd lnetoglobalin (Webb Johnson and Alford, 1974) These proeins coagulate when beat is applied (Lyster 1979) and are easily collected llr precipitation Heat denaturation bepins when the temperate is close lo 68°C and increases with the Hime-temperature combination used daring heating

In practice these properties are exploited 0 produce the specie airy products know 36 whey’ chaos"

hich are tainly manufactured largely an the cvties found the Mediteranean (Pornust, 1979: Ramet, IONSe; Kandarakis, #986) These procs are fot genuine cheeses, because they ae not blued Aire from the coagulation of mill

Pracessing consists of selecting whey rch in soluble Prolcins and, preferably, drained trom hard cheeses

‘made foun rao terized ith The vhey is loaly

an 95°C and he at tha temperature for 9 father 1S 49 30

heated for 2010 45 minutes to between 7

rina The Fist clotted pails appear a around 78

1 SOC depending on aeidly andl whey” protem

‘concentration The clisters of coagulated proteins tee atthe surface of the whey and can be easily

collected using simple echiques such as fi

"ough clo or skimoxing with a ade

“The degree of heating itivenees the quality of the

‘hese, Above S¥°C, the texture tnd to becom dir hander and more granular A cooked Mavour makes the she ess acceptable, Hefow these tempertures, the hist ‘ne sina, crumbly and iia to gather the Preciptte is watery and druins slowly: Cheese yes

able and elosely dependent on thế ribaee 0ˆ the whey andthe water content ofthe inl prot For Camp, the yield trom cows milk cheese wey can

The solids content of whey’ cheese

is around 20 0 28 percent the pescenage of fan dry rater iy generally boise Hand 45 porent

The keeping quality ofthe product is poor becuse of the high water coment and reduced acidity (gH SS 62) Th

‘in cooking and pasty [Numerous alternatives ta the above process ate used, These processes are aimed at

nese ca be eaten like othe cheese or used

improving recovery of whey proteins and inweasing the total solids ofthe cheese 4 40 t0 50 pereent as

‘sith scat oF bracein The best method consists of saline fom 20 fo 30 poxcoat whole mil to the whey for increasing the avidity 0 pH 4.6 10 S8 {Kandarakis, 1986), Acid development nay he supplemented with

‘organic aids such as atic, cite, lotic oF tara:

with mineral aids ike phosphor acid or by using

avid whey The addition of sats (0.1 to 0.5 percent

‘alelum andr sodium chloride) is sometimes sed for

the same purpose

‘The most

modern processes imolve more Sophisticated techniques suchas ultrafiltration 4

whey proteins prior to heating or

‘centifgation to enhance separation of precipitates

Whey chaese is generally accepted by local

consumers oause of is typical taste and smooth

texture, Nutonal value is high hecause of the

richness of whey proteins in essential amino acids

mainly cystine and methionine Pane, 1978)

‘Summary of butte-making technology

The fa globule The ft in cow's mitk is emulsitid as

fat globules 3 0 micrometes im diameter The fat

lobules have & heterogenous structure composed of

the pars: an external membrane a central core of

Uiglyeerdes with high melting points and am

Intermediate sratom of tiglyeerids wih Tow meting

pons The stay ofthe Fat emilsonis dependent om

‘he integrity ofthe globular siete

Buuter making consists of destabilizing the emulsion

in onde ta concentrate the fat conten from 35 0 45

percent in milk to §2 pecem in bater Thì

transformation proessls tưough several mechanical

snd chemical tages

The phases of butter making, The fist sep of biter

processing isto separate the milk to obtain teat with,

4 fal content about fen times higher than mk, The

process cam be cari out by natural creaming of il

ám the traditional way or by modern contigat

techniques

Sometimes, when the acidity is in excess of 2

poten, it is necessary to neutralize the cream in onder

to avoid coagulation during heating and development

of disagreeable Mavours in the baer Newtriation is

catieỞ out either by dilution with water and further

separation or chemically using soi hydroxide

Heat treatment of the eieam is recommended to

<liminate the bacteria and enzymes that could cause

quality problems and spoilage For this reason, the

‘ream i heat treated at a temperature of 90 10 95°C

for between 30 seconds and (wo mites Heating

lakes place in containers (vats, eaulrons, et.) on

tubular or plate exchangers, Opin de-gassing may

be used to remove disagrocale favours which say

heating the ream is cooled to betwen & and 14°C for ripening be dissolved in the water or fat A

Ripening, or ageing, is used to lower the pH slightly,

to develop favour and o regula fat en stalization, Bological ripening is effected by adding a late stant for 10 t0 16 hours at § t0 14°C The or city required for traditional chursing wethods is 10.40 to 045 percent but oly 0.20 to 0.35 percem for comingous butter making During ripening lactic acid hasteria ako produce flavouring molecoles such as diacetyl which ae important in buikding up dhe typical cooked or hazelnut Favonte

Physical ripening is caried out «0 regulate the proportion of soi and guid fa, At low temperatures all the fats erystline, leading 1 long churning times and very hard buster texture, H the temperate isto high al he at mils andthe butte will he very sf resulting in considerable fat losses inthe butermilk Another important factor in physical ripening is conto ofthe eram cooling rte If this 00 slow fare fa

erystals will orm, leading wo a Fracture sandy texture

tn the butler he coo

se smal and not delet seis 0 fas, the eye inthe mouth Asa esl the leu of the butter significantly improved

"The final phase of butter making consists of breaking

a limited mimber of fat globules in order to expel

‘sal amount of iif that will essare a continuous bond with adjacent globules, When this boring takes place grains of butter appea In order 0 faite ths

‘development the fat globules have to come together

hari chuening Tiss brought about bythe formation

‘oF foam as churning wf the eream begins As ening

the bubbles get smaller, making the foam fore compact and so applying pressure on the fat lobules, As the bubbles becom increasingly deme, more liguil at s squeezed out and the foam becomes

sa j eoTipses The discharge ofthe lig Fat

sed by the impact of globules agaist each ther and against the surface ofthe churn, Inaedisely thề hutier particles appear, the foam collapses and ulemmil separates fom the buter

‘When the hater particles become lag Separation, the bustermil is run off and choi, working continues If the bute sintended fort

enough for

provide effective protestion against micrabial

contamination and mst be opaque alight in

fit oxidation The keeping guaHy øf the pmduet

depends on the residual cootest of microbes and

senzymes and on the stra

remperatute, For storage over several months or yeas, deep freezing 10-20 10

38°C is required n critiona!protetin mets, the

buter is melted and boiled to desteoy sporlage

‘ongunisms and enzymes and kept for several ants a

«cans or glass or earthenware jars

Chapter 2

Camel milk and cheese making

In trtiona! pastoral systems, camel rik imi set

for feeding calves and for human consumption, To

‘quae ofthe udder are wslly slot for king and

segregated sith ropes, while the cal suckle the eter

to ques Rarst, 1987 Rams, 1980, Ramet, 1090)

Milk for human consumption is usually drunk

immediatly aftr milking tan alo he consumed as

femmented milk made by natural a ie suring over

scseral hours in askin oF clay container The fermented

rl may’ sometimes he separated hy vigorous shaking

the aid skimmed milks drank and the bute used for

‘coking urcosmetc of micinl purposes Yagil, 82)

“The processing of camel milk ino chooses sad tbe

Jifficll, even smmpossible (Dickson, 195L

Maubois and Ads 1969; Yagil 1982; Wilson, 1984)

is surprising thar alhough the majority’ of pastoral

stems have produced a least ane type af cheese, no

trations methods exist for making ehoese from camel

milk This might be explained by loca ulus oie

allow the consumption of camel milk oly as dn aud

exclde the possibilty of trae Is also possible that

he highly perishable nature of cheese in hot desert

simites his not fen condicive 19 exe

Gas

btcenilated commis

m1

that camel mu i eehniedly more dieu to process

than milk from other domodie day anumals A

bibliographic review inicates that im the Ahagaarepion

and the Sinai peninsola only a few rae cbeeses ave

‘manufactured by acidic separation and beating of elk

plein (Gast, Maubois and Adds, 1969; Yagil 1982)

These products soem to have the characters of

perishable fesh cheese with high moist coment

Shellie may be increased o several ont by awd

sun dying (Abeidertsbmane, 194), smote thi these

cheese types da not ome unr the stn defingion of

cheese hich reals trom the simultaneous action of a

rik eloting enzyme a Isetic song (Rar, 1985),

COAGULATION

Enzyme coagulation

Action of eloting enzymes on camel milk Most

atlempis to make cheese ftom camel milk Have

revealed major difficulties in geting the milk t0 coagulate Iii field attempts increased the rennet concentration compared with thi usually used for

loting co's mill by 50 ta 104 times (Gast Maus and Add, 1969: Wilsoo, 1984), More recent atlemps

‘oni tha the enpet coagulation of came milk is

to to four times slower than for cow's milk tated

‘ner the sane conditions (Ramet, 198Sa; Fara and Bachan, 1987; Ramcl, 1987 Mohamed and Larsson-Razikiewi, 1990,

“This specific behaviour hasbeen observed with most

of the eloHing enzymes used for coapulation

Significant ferences im the inhibition of oth sti Tole to the origin of the ens h ve be rote however, Several observations (Ramet, 1988s

Ramet, 1990) have shown that ovine pepsin coglates camet ik well Calf rennet andthe leting fezyme extracted ftom Mucor miei have an effect

than bowie pepsin, Chymosins of etetic origin and proteases of Endothia parasite have the lowes flac (Figure 2),

Milk cloting tals made under sila contin sing cither milk reconsttated

ovine il (pH 6.68) or fresh aw cae it cpll (6.55) have demonstrate a noticable improvement in sloMing camet nu comped si cow's milk ashen calf rennet, Mucor mice’ and Endochio parasitica proteases and genetic chymosin were used With ovine pepsin, the clotting time was five ties shorter

in camel milk (Table 10) This unigue behaviour of pepsin could be expitined by is higher affinity for nel mill ad ts ied aetvty ata near neutral 9 These lierat afin, which depend on enzyme could be pay explained by the incidence of

“ensronmental fasts (pl eniperatre onic stent

ân carmel milk of spocitic protease inibitors andor ptiular casein miele stmctre Timing acceso the protease lo the Kappa casein substrate, These Inypoeses ane yet 10 he confrmes

“More genril, it amist be stated that some nomads

{in the Sahara and Sinai sce 0 be able to make choese

sing pts of the stomach of the desert rabbit as a

coagulating agent (Gast Maubois and Adda, 1969

‘Yagil, 1982), This somach contains pepsin (Lehe,

1991), More recent work carried out in Egypt (EL

Abasss, 1987; ELBatawy, Amer and Ibe, 1987)

shows thatthe pepsin pradice frm the soma o he

sult camel is just as good in terms of activity ad

aility However, this work didnot desl with the

general ability oF the chưyng for chee

‘appears that using the stomach of young camels for

making camel choose as never been investigated or

making te

tied, which is strange, Moreover, no work has

‘tioned the actual enzyme composition of the

cal slomach, sae

‘Aurther distinguishing teaure ofthe Mucor mite

‘nage when used in weak concentration in camel milk

{so case part inhiBidon, d shown by the non-near

relationship betwcenthe clating ime and the inverse of

enzgime concentration (Figure 2) This phenomenon,

previously observed in rave cow's milk, probably

‘ovginates fom the enzyme reacting with the she

proeins, As a eomsequence, in practice the enzyme

‘quanti, sto be sity inereased The inhibitory

fect disipeas whon the milk is heat weated wader

high từmelempan

(Ramet, 19854)

Curd formation and rheological properties Many

jbservations of making cheese from camel milk point

to the difficulty jn messting the early sages of

cagulation An empirical appraisal of the physical

Properties of mk during the Tigid ¢© gel transition

[hase isnot easy ecanse ofthe persistence ofa dfs,

e8dtike pseudo-ge Further build up ofthe eaaguins

isslow and weak (Ramet, 1985a: Farah and Bachman,

1977; Ramet, 1991; Ramet, 19949) The gel etre is

charcteriged by low chrdiely and

Moceove, the fragility ofthe cum is increased whe

eid Fermentation occurs (Rar, 1987; Ramet, 190)

On a practical note this rheological đaslopme

indicates the need wo inrease the sped of eoagtlation

in order to avoid making the curd too weak to withstand

the mechanical ation used in ding

‘Thisuique shsological behaviour hasbeen traced by

engidedl methods (Gas, Mabois and Adds, 1960

Ramet, 1985a; Rome, 1987: Mohamed and Larson

Ramikiewicz, 1990; Ramet, 19944) and confimed and

quanti by instmental methods, Figures 9 and

show examples of measurements made by gelogtaps

‘enzymes s probably largely duc tothe composition of the casein micelles Some recent research bas shown) that the kappa casein, representing the micellar fraction which tects ait the cating enzymes, has 3 dierent lgcio-potential frm cow's ilk, which

‘eauses lower eladtophohoie mohjly (Farah and Fani-Rieen, 198; Jardali, 1988: Mohamed and Lanson-Razmikiowiez, 1990; Farah, 1993; Larsson Raznikiewicr, 1994.)

“Thịt mnusal bebovidur indicates very spose casein micelle composition characterized by a low proportion of kappa casein, Relevant daa are liste in Table 3, which indicates thatthe average content of

‘ap casein in camel mk Feom various sources ses

tw only about 5 percent of tra easein, compared with 1.46 escent in eow's milk ard, 1994) Camel rik casein also difers terms of micellar size

‘Table th, Instat measurements showed thatthe ean diameter ranges from 280 to 328 mieromerss,

about double the 160 miogomties in cow's ith (ara and Bachmann, 1987: Janda, 1988; Farah ad Race 1989: Fda and Ramet, 1991),

{9s important to emphasize that seasonal variations Jin the composition and sizeof casein micelles have alo ben foal in cow's milk, These ave caused by thy saiable effect of environmental Gctors sue as temperate and feed availability: For examp) noticeable variation inthe diameter of the micelles from 150 to 250 nm was observed in hulk mi collected inthe eastern part of France, During the hot Season, the micelles are larger and lower in kappa

The same milk had a reduced whilty tò coagulate compared with winter mk The cleting time with renaet was longer and the Fires of the

‘ud significantly seduced, Tn the cold season, 00 he

‘other hand the micelles weseeicher in kappa casei, soagulated faster and produced sương

(Ekstrond, Larsson-Raznikiewier and Pesimann,

1980, Niki and Arima, 1984: Scher, 1988), Adding rennet to camel mill causes proteolytic reaction which ean be traced through the development ofthe quantity of non-protein nitrogen The trend of

he carves shows that hydrolysis is similar in anal rnilk and cow's milk, although the percentage of

‘appa casein is quite diffrent (Farah go Bachmama,

1087, Mehaia, 1987),

1 appears tht the secondary reaction of the eloting

process in camel mik, which comespands co the

aggregation of casein miele aces definite

sequence rhashoen observed by electronic microscopy

‘hatin cow's milk homgenous rework oF micelles

exited te time coresponding 1980 pecent ofthe

vis cling time In camel milk, the auereyation of

roeeles costs later and the nett i soe a ess

dense (Farah and Bachman, 1987), 1 scems that the

reduced abit of micelles to potserize is the result of

the weak capacity ofthe substrate to Tink cain bonds

‘wth prices ‘The large-size micelles are known tobe

lover in caleium than the smallor ones (Scher, 1988),

Measurements made chewhere dig the hot season

stowed tha the content of colloidal ealeim hound ta

es imcansl nik was mach Tower (35 pexcent

ofthe tol ediium) thân in cow'S ml (6Š bao) and

that therein content was also sc rede by

svaterrestiction (Yagil and Eizion, 1980; Yagil, 1994),

“The mor cole of caleium in the coagulation pocess

the ive

'xeogbonted by te fad tại eoelled enrichment of

camel milk with ionic calcium drastically reduces

loi ime and reinforces the ge strength more than in

cow's milk under similar conditions (Ramet, 1985

‘Ramet, 1987; Farah nd Bachmann, 1987; Jana, 19

(Ovid Elya and Ramet, 1904)

Inflence of oa sald lì knoan thế ty thelogied

optics of ed also depend cose onthe otal sls

‘nthe mils a ar impo as ol li xe ifreised

Tre components of the dry master behave differently

dhving clot Formation The casein tent has the major

role the higher 118 he Songer the formation of the

Inicelle network, Fat snot active in gel formation, Fat

lobules are caught in the cissin mats, vere they

decrease clot righty Ata similar ft percentage, the

`

‘han with Inger ones The soluble substances do ot at

itty om gel formation; hey nly modify the viscosity

ofthe whey located nthe intesgce the ced

Analyses show that dhe dy-mattr content of camel

milk varies azcordng to the origin ofthe ik Table 2,

Sirsa variations exist dhe Fat and pose conten

Generally, however, the Ft tha Ue aroun of ese

components are lower than in c's milk pli the

Tower theological quality of camel milk curd, Such

auerse effets acer most hen animals have restricted

accesso Water: sen observe, fr example that

tot soli can fall fora 14.3 t0 8S potent, protsin from 46 4025 percent and fa rom 13 #0 LI percent (Yagi and Exzion, 1980; Yagi, 1994

Athi cause of weaker cart eigiity in camel miki The vnal sie ofthe fat globes, which ae between 1.2

ae coagulation of camel mils is governed by lactic geal bacteria whic onginate either ro the fas nil

fr from the extemal inoculation of late states Ramet, 1985a) The ability of eared milk to acy i

in tum, dependent on several compositional factor hit interior with hactesial gros,

Milk may be considered a medium favourable for Icrbial growth with near neutral pH, a high water aetiviy and a large vavety of nuttive substances faciiating the proliferation of eels incteding lactic acid bacteria, Lactose is the mtrient of prime Jimpomanse, Abough as content in camel ilk ray sary geealy depending on feeding and watering conditions £Yapil and Htzon, 1980; Yagi, 1994), it appears that lactose availabilty is always satisfactory,

‘eve in cases of song aidty There are no studies of Introgen nustion that assess the precine requirements etic bacteria in relation a the specific composition

of cam! mi

‘On the otber ha, bibliographic review indicates that rawr came milk contains several antimicrobial agents that can limit microbial growth to alhisher degree than in ilk fom other dames animal, Significantly high levels of Iysozyne (Barbour ez al, 1984; El Sayed

‘tal, 1992; Fara, 1993) and vitamin C (Kon and Cowie, 1972; Knooss, 1979; Yagil, 1982; Yi,

1984) are reported Move reezaly, the tivity of other natural proteins such as

and immunoglobulins as stdied TManaam eta, 1989; IDE, 1991; EI Sayed et

cl 1992; BI Agany.1994) Eah of these a

and Ervin, avin

ns pasesces a selective spectrum of activity agaist

site sins o hacer ad vines

As 4 major consequence, when fresh aw ail is allowsd to sour, acleriastatic pod is observed for the first few hours alter iki This lag phase is sealer in cams ilk (four t sn hours) thai o's milk (to tothe hours), Acid development tes ase slower throughout the incubation period (Ramet

1985: Ramet, 1987; Gran ea 1994) Aer camel

milk has been heatsreated using thermizing or high

pasteurization conditions, partial inition persists

"becase the animierobi Factors cold be

94a; FI Agar 1994), Another eason for the reduced acid

prodvtion rate appears to be related © the higher

buffering capacity of eam! milk compared wih cow's

rik (Rao, Gupta and Das, 1970: Ramet, 108Sb;

Ramet, 1987; Farah a Bachman, 1987),

Ipearesistan than in cow's milk (Ramet

Formation and rheological properties of lactic gels

“Throughout the course of acct of cows mil,

progressive neutalization of the electric charges of the

les curs ealing to the emerzence ofthe

curd The ceagulation point occurs earlier when the

ciity and temperature are high (Veisseyre, 1975:

Ramet, 1985) Tn camel mith iis difical vo detet

similar development because the formation of the clet

is slow and unstrctred and resembles a flock rater

than a precipitate (Ramet, 198Sb Ramet, 1987; Farah

and Bachan, 1987)

DRAINING ABILITY

Curd properties and syneresis

“The ability of cutds to drain is iret dependent on

ticirsheoogical properties, which develop thưougho

he hardening phase, taking into account the

development of firmness ad elasticity,

The extreme weakness of camel milk curds causes

the destruction of the casein network if physical

treatment applied at cutting and mauling is not done

and slowly IF these conditions se not

served a significant potion ofthe dry mater ofthe

rn is noe retained in the cheese bt lost in the why

Recovery is then limited to about 30 percent, whe

itinereases to aboot 50 percent for cow's milk and 68

Perent for sheep's mil under similar manufacturing

‘conditions (Ramet, 1990),

‘The draining of curd made from camel milk 8

characterized by rapid symeresis compre with cow's

rik, Figuwe 7 shoves the lage difference during

Wwheving off measured in a curd ebained chilly by

aid coagulation (Ramet, 1987) This developement

appears tobe consequence of the low ater Fetention

‘capacity ofthe gel ease ofits rather limites cassia

sontent, Another factor is thatthe hydration of cael

vivelles is reduced by the low bare Fraction which s very hydrophilic, and hy the restrict

carefully

lk casein

surface area olatve os high volume (lard 1988;

Schor, 1988; Fra, 1954), If shoul be noted that similar signiieam relationships have beun observed when seasonal variations nthe composition of cow casein micelles have been accurately’ maasured Inthe

Ft season micelles ae larger bat lower in kappacscin

fd the resubing curd has a weaker waterretention pacity than inthe cod season (Seer, 1988)

The fac thatthe aciication rates slower in camel anil appea elect on wheving of

Tk must be seressed, however, that under these s0ndiionsthepưoscive elect of ait im preventing the spread of spoilage organisms is delayed Is hs necessary to mk the cheese under especially hygienic

to have no aber

sondiien

Whey composition

‘The composition of camel milk whey ischarateized by

ut 70 and 65 escent, respuctively, wheres the dy-mater content Is

higher otal solids than e0w'S ak, foftes tower in camel milk wey (Ramet, 1987, Ramet sand Kamoun, 1988; Kamoun and Bergaovi, 1089, Rann, 9848) I basen emphasized ha at contest

is particulary high, teaching the to four times the Value measMEdl in whey from cheese made under Similar conditions from cow's auilk — 03 and 13 perce, espectively, Tis concentation is equivalent te

‘mre than 6 pewwent of the content ofthe mie Rane 19890; Mohamed, 1990; Ramat, 1994} "The smal ize

of fat globules and the fealty of the casein mic eto ae the cause ofthese loses

The sey from camel milk cheese sent hy ts white colour compared wih the greenish whey From co's ik chowse (Ramet, 1989; Ramet et Kamu 1988; Mohamed and Lars Razrikiewiz, 190; Rat, 98a) Ths propery of camel whey is paul he rst

‘of concentration of alps (pein at globus)

‘shich, through complex điữiaeton and refaetion phenomena, oloue Another reason could

be the fw consentmtion of nolan ina ails (Webh ohnson apd Alford, 1074: Farah 1993),

RIPENNG

Lite inonato is avaiable on the sping of cheese rade from camel ilk, What saab is based on esperimendl paidueton cared out using small (qutites of milk The frst commercial proustion Stated rvenily in Mauritania in a ness, purpose built camel cheose-saking facility (Ramet, 1994) Trends ray this be observed hut final conelusions cannot yet ale

The techno of hing cbs rm os

Results from sources in Tunisia (Ramet, 1987)

Saudi Arabia (Ramet, 1990) and Mavi

1994) show thatthe taste of fresh

highly sasfactory The smoot testute ail ship se

ofthe curd were well fked bya esting panel, Siar

results were observed by most the panellists fr soft

2 tral sls coment of $5 1-48 ponent at

the ead of draining, However, some ges trained

the sensory evaluation of sot cheese mane fron cow's

"

cheese is

——

ilk have noticed & rougher texture in camel cose

“The somewhat chalky structure is probably a resale of

‘the reduced fat content ofthe cheese because oF high at

losses inthe whey an the weak watering capacity

‘of camel milk curd The sensory profile of sot ean

hese is very similiar (0 that of low-fat sole cheese

made from cow's mith, A simile erly granular

tovtre has beet also found i semishard and had

cheese (Ramet an Kamoun, 1988; Mohamed and

Lassoa-Rarnikiewier, 1990, Ramet, 19a), The fst

‘servation confims that the cheese hesomes less

smooth whon the fat and water conten decreas,

Ather defect hạt reas ichy hese cad has

sometimes boon noted, The cheese tends to are

quite stony co the tongue and palate while is being

chewed, No explanation of this is Known hut i sees

thar some properties ofthe cael cheese sch as th

high level of short-chain faty acids and their

sigaiicanly hinh meine point (Abadeiha, 1987

Abu-Leiha, 1989; Farah and Ruegs, 1991s Metis,

1994) may be relate othe phenomenon,

Temporary bitemess has been note in some st

and semichant cheeses (Ramet, 1987: Ratt and

Kamoun, 1988; Ramet, 19948) The detect is detested

mainhy Aler the choose has been swallowed, This

perception of bittemess is delayed beciwse the

ceptors sensitive ro iter molevies ne locate at the

bk ofthe tongue

“The prohable origi ik

hese has not heen clearly deermined ls own tht

bitemess in dairy products way be eased hy Factors

such as alkalis of ingested plants, sills of extemal

‘of the bitemess in came

sly calcium and magnesivas chlorides

and carbonates or biter peptides generated by casein

hydrolysis, The mast likely case is thoxe proteolytic

resides which agcumulate when tbe pH ofthe cheese

sil proteolytic activity fron the lowing enzymes emis i he cura The fact that is is low and a high

necessary t9 averdose the cloting enzyme to sped up

coagulation of eamel rik ncaes the lst possibility

asthe origin ofthe bitlemess

PRODUCTS OBTAINED FROM WHEY Whey cheese

Prodising whey cheese hy coagulatin Proteins in came mitk whey is more dffiul than wih cow's milk she, at east when teatonal methods are used, When camel mi whey s heated aggregates of donated proeins begin to foe at temperamres otween 72 and SIPC (Ramet, 1987, Mohamed and Larsson-Raznkieicz, 1990; Ramet, 19a), However the particles emin very small and isolated an do no

the sole

ome together during fanher heating asin cow's i {When ft at ambient temperature for en 0 16 hours, these disint phases occurs an upper Hating layer

‘composed of wate, proeins and ft; an intermediate

and & weak white

layer made wp of clear hey preciptate atthe hotom The separation of te upper part by radiional simple fration is ineffective Alematves to this process, seh as action with lacie and chic aids, ation of calcium and sim Ctlordes or adion of 30 percent of wc camel milk,

do not improve collection of the panicles (Ram 1987: Ramet, 1990), The only way t separate isto use

4 centrifuge, which allows a watery concentra to he recovered with about 16 to 22 percent total solids (Ramet 1990,

Tie unique behaviour of came mi whey compared with cow's milk whey cowl! be explained by siren

in the eoripostion of the soluble whey proteins and thoi higher heat stability (sce ‘The main constituents on p 3) thas aso beea noted that when

cow's milk is strongly heated, a reaction occurs horweon hetrlacloglohulin and Kappa casein that makes he formation of rgeagaregses easton (ite et

‘af, 1962), Absence in eave milk oF protein sina bet-tactogloulin and low kappa casein content could

‘ase this ferent beuviour, Finally is possible that the high amount of fat in camel milk whey could have some adverse effect on the surface properties of the

‘whey protein particles, leading to thei dispersion Winey butter

Given she very high ft content of camel mith why, the question arises whsther i 6 possible make hater

that making totter from came milk whey has bees controversial for Tre review ofthe Mrature indicate

2 long ie Many nomads do net produce butter From pure fresh camel mill (Dickson, 1951; Wilson, 1983),

‘whereas some ators report that butler is produced

ì Resco has conti hat hater aking from cae

under good management candtions (Yagi 19%

rik whey is Feasible but more itfcult than with com's

rilk whey (Par, Sie and Bachmann, 1989; Ramet,

1900)

‘The ficulties seem to stem fom the properties of

the fat globules, which ae gonerlly small with a tick

‘membrane (see The main constituents on p 3) For

these reasons, the mechanical resistance of the fat

lobules is probably strengthened, which ress in

Tong churning time of about five hours when milk is

diecủy processed without pdor conteitugal

omeentration ofthe fat (Ramet, 1990), If he agitation

of whey iseatied out afr increasing the acidity t pH

50, churning time is reduced to one to two hours

“The concenration ofthe fa emulsion ino cream by

‘oF hy ceniluggion as found less

‘easy than For co's ilk becase ofthe sl sizeof the

lobules, Ta obiain 20 to 30 percent cream fat, i is

necessary to double centifugation This leads to a

significant reduction in churning ime, which promotes

the oveurrene of buter gas, The time falls between

five and 45 minutes, depen on etipcitire, fa cone

and team acid (Fah, Stell and Buchmann, 1989

Rast, 1990) Aching the cream makes chung faster

but overs far ecover in bute Figure 8)

‘A eature ofthe composition of camel rik it sts

low shon-chin Fatty’ ae content and high proportion

fF palmitic and stearic acids ‘This results high

‘melting and solidification points compared with cow's

nik: 414 19 41,9°C and 303°C for camel mith and 28

to 32°C and 228°C for cow's mith IL seas shown

cathe (sce Summary of butter-making technology on

8) chat temperature important to balance the

Dhysieal state ofthe fat The major roe of temperature

is contiemed by te fist that formation of butter grains

oes not occur at T0 to 12°C, which is the wstal

chuming temperate for cow's wil eteam, and that

‘over 36°C the baller yield begins to fll, The best

conditions for making tutter are 25°C for a 225

percent fat cream with a charng time of minutes

(Para, Streit and Bachmann, 1989)

“The sensory profile of utter made from came ih

is condoned by its very white coloue (Farah, Steiff

and Bachmann, 1989: Ramet, 1990), which probably

resolls froma high amoant of non-fat components such

28 proteins inked othe at elobales, and considerable

fetention of buttermilk by capillary action (Ramet,

1990) The bute is ereasy and sticky when eter or cut

With kaif (Farah, Sire? and Bachmann, 1989

Ramet, 1990), The Maso is mental and unk buter

made from eos tk

The foregoing remarks on buter processing ae only hypotheses ay fo the Testy of making utr from camel ik whey, Is obvions that the fat in whey is more adulterated than in milk oF cream as a consequence of the physical and cheinicel processes applied ducing the diferent stages of eheese making I appears that churning times and fal losses in tera,

‘re more important than fr fresh eran, For the same reason, the tse aod keeping qualities of camel whey batter would also be les satsFaetny

Drinks made from whey

“Trials have shown tha camel mile whey may be used

to make acidified drinks, These drinks have an sveelent nutritive vale because of the presence of essential amino acids, lactose, late acid, vitamins and minerals, The taste properties of whey a well know ivi sweet or slighlly acid depending on the level of city These dominant flavours ean be masked if milky taste i to be avoided by adding concented {vies from ac ris, Becase of the opaque colour of whey and the posible presence of a whey protein rept cis better to use cloudy juices that contain

lp such cits fruits, The low pH of those nic get the whey a characterise refreshing tases the

‘ukiiona acidity is proteston against development of

‘most spoilage oxganisms Consumption of the product should be within (wo 10 three days Addition preservation by pasteurization fs

term storage,

sary for Tonge

he seta fring cece rm

Chapter 3

Ways of improving cheese made

SELECTION OF HIGH-GRADE MILK

“Milk sed for making wood cheese mast meat certain

eiieal physical, chemical and microbial standavds

“Those standatds, which should he hgorously impose

when the milk is infended for human consumption,

have been widely reviewed in specialized

publications, More detailed information on quality

sontol, milk coletion and keeping methods may be

‘oblained fom the following publications: Ramet

19WSS; Seo, 1986; Robinson, 1990 Weber, 199%

Lambert 1988; IDF, 1999, The iain pois are

‘covered in the follwing sections

‘Segregation of abnormal milk

Milk ust be abined only fom healthy animals Nie

From sek animals may’ contain haeteia harmful tạ

constmees, IF the animals have been ated with

antibiotics, their milk may include residues whose

residal action night ib developent of lactic ai

states when the milk is processed into femmented

ity produets suchas cheese

Colostrum milks, seereted a the begiin

lactation, ae mot suite fore i

low casein and hgh sl eels, They should be avoided

for one 10 two weeks after calving Camel milk

produced by animals ander seioas water shortage

conditions contains abnormally fw milk stds and its

se mk

heose processing ability is poor It shouldbe discarded

‘or ied with milk from other eames that sicher i

dry mater or with other ik thats better ape! to

theese making

Microbial quatiy

“The potential vectors of milk contamination are

‘numerous and of varius origins, They inclade: diy

animals, soiled udder, contaminate! dairy utensils aad

clos ad diny hands of mikes, Stet observance of

scoped cleaning and dsinfesting proces is vital 10

fens good quality nik and dsiry pred,

“The fllowing rules should he flowed

+The udder skins often heavily soiled! with manure

from camel milk

sind din, fs is necessary to clean i eaefully wih 3 Jesse paper towel ora cath fel msened in lukesarm đìnaoanl The elder should then be sipeldy

The fest ik drain from each ler quaner lx always charged ith microbes should he collected separately ad mot mixed with the milk obtained hac

+ Microbial contamination may be caused by inadequately wained mihers To get good quali ilk, ers should

he healthy” people prricolely on the hands svanh and dy the hands hofoe milking:

rt ane utensits with iy hands thoroughly clean and lsinfct cach ateail in otc wih ill

Without open wounds

2 or eo0m without dust inset nana oF sagt wer

-vork inaclean pl cool milk rapidly 10 4 (0 4PC AF processing or

‘consumption does nat our within five 4 eight thurs of milking (Ben at these fow tempera, psyehnotophic bacteria may grow The tot! raw

‘ilk olin potod shoud nat last more ha 2410

of contamination Surfaces tt are in coma with ik an diy 48 hours, depending on he products must be effciny cleaned and disinfected

efenlion time of microorganisms is round 2069 30 mines under optimal growths

‘oditons temperature: 25 40 38°C: pl: 6.63; water tivity (As more than SŠ pereenl)

cally, the following manual cleuming and sisinfotng metbos shoud be Follows:

"`" he Soak the utensils if cleaning can wot be done

‘immediatly + prepare non-abrasive alkaline detergent solution wih a concentration of O to F percent at a temperature of 40g ASC,

+ soak iy utensils and cover all sarfaces for ie to

‘ beush vigorously witha nylon brash wo remove all

debe and sais:

‘rinse with drinking-water to remove all aces of he

detergent,

+ aery and stone utensils aay frm moisture, dst

ard insects

‘before re-use, isinfcct utensils by sahing in

chlorine soltion ata concentration of 250 mgrlire

A 38 1940°C for ten ta 20 minutes:

‘rinse again with potable water t0 eliminate the

Chlorine cess

shouldbe noted tat

‘most alkaline detergents and disnfectams are

abrasive to dlamnum and sts alloys at room

Temperate an eanse blackening and corrosion of

the mals the given soaking Himes must not he

cenceeded

+ stainless steel is resistant to the ation of detergents

even a high temperature hut, unfortunately i is

antacked by chlorine disinfstams at over 35°C the

seneenrdion of chlorine and its germicidal

ficiency fall with vine Because of os af gaseous

chlorite

+ nse of low detergent and dsinectant concentrations

axl shor soaking tine may cause emer

` agents in

‘detergent and disinfectant solutions

‘use of soft wale forsinsing is ecommmende

‘the coacentration of chlorine in indus

disinfectant preparations varies from 12 10 50

<hlorometic degtees (1 chlorotic degre = 3.17

sim)

MILK PREPARATION

Heat treatment

Raw milk alvays contains scroom

lmportance and variety’ depend on the beak of the

animal, hygiene conditions daring milking, the milk

collecting system and time-temperature conditions

ring storage (Ramet 198Sb: IDF, 1990), Among the

microbe population,

dangerous because they may transmit diseases to

nisms whose

Tnumans pathogenic germs) or cabse defGets the

final produet (gas-forming, pretelgtic and lipolytic

cell) Depending on the extent of microbial eroh

and subsequent cell concentation, uh contamination

may cause problems daring processing oF sensory

defeats inthe Finished prxuet<owine, oor texture,

bitteress and ranciity) or lea © tbe destnation of

the produc,

Raw milk contains varying quantities of lati acid Baslena suiable (or processing cheese, These bacteria pradace the Inte acid required fr futher dining aa

‘cid proection ofthe ead, This natural aiicaion of

anil is, however, variable io speed and iment

ste 10

because i depends on factors thar are ot ei time As esl the processing and inal quality ofthe product would not be regular Heat

bulances out these unos hut requies the ation fof hctic laters prior the coagulation phase For hhypione anal echnical reasons, heat meatmeat of camel nik prior to processing into cheese is strongly

recommended

‘Onthe bss of cheese-making wials cared eat under

‘avions conditions with milk from difleren: ongins Rann, 1987; Ramet, 1990, Ramet, 1994 Ramet, 1005), it appears hat hermizang (62°C for one nate)

‘ pasteuizing (72°C for one minute) are best for

‘nicebial stabilization of camel milk apd fr peeserting

‘evasion curd lowing (Table 1) The results shove

‘hat silk eloting and esining ability ane progressively reduc if higher heat eat condions ane nse,

‘Tho maia features ped during coagulation were & longer sloting time, a decreas i the firmness ofthe

url and an increase im brileness Similar chang roti after heating cous milk were caused by heat induced chemical eeacions, sich as formation of 3 complex between kappa casein snd betslactoglobalin and a decease in soluble cali content, These resstions decrese the response of the modu (0 the action of mith loting enaymes (Webb, Jenson and Alford, 1974: Rams, 1985a; Eck, 1990)

progressive deerease inthe propensity ofthe cund

to whey off duving draining has ben noted elated to

an inetease in the tm-temperature conditions used Cưởng beating (Figure 9) This development of the coagulum originates mainly from the higher water bonding capacity of the whey proteins caused by feat deaturation The curd subsequently remains more ois! and cnambly and the dry mer losses the wey inerease in sltion to the itleness Table HL

‘With regard to the above observations, i appeals ncessary to regulate the heat oatment of camel mile according t0 the total selids canten requited in the

‘cheese atthe ed of dining, Mik (0 be processed into fresh or soft cheese should be heated under low peteafxion condilons (72.10 76°C foe 15 w 30 secon), heres for production oF less moist ches

such as Semicbard aa hat t0 thatming at 622C For one to swe minates only should be cari out

The cits of in hese rn sate nữ

Another Factor 10 be taken into assount when

determining heat reatment conditions the oa sls

coment ofthe milk: The adverse eects have 8 more

elect on milks with lower dry-mater and

casein contents han tho richer in these components,

Camel milk produced in the hot season by anials

hon of food and water fas poor cheese taking

pabiliy (See Composition of camel milk on, Sam

Coaguiaton on p 11) Such mil should not be heated

0 avoid further reduction of is cheese-making

capability Hygiene and technical sks

processing mean that these poor milks should he

rejected For other ks with higher tol solids and

ase coment Hay be suicient to hale th

temperature conditions of feat tveatmient with the

seasonal variation in milk composition, Further

experience of cheese making i requted to establish

these parameters in relation ta de er iitstions of

the cheese-making prowess, sh as yield and taste and

texture quality,

The heating equipment nus be capable of proving

even eaten! throughout the alk Spevial ples oF

lubolar heat exehangers are best suited For this

‘operation, When a Kettle heated over afte is used for

sma scale processing Family or household level the

during

rik must be sited continuously dering the heating

races in order to aod lcalized overheating next 10

the vescel wall

Tk nwsi be remembered that acid milk coagulates

when ated lading to precipitation of casein on the

heating surfaces The ait ofthe milk should this be

checked by tiation or plT meter before heating stars

[Mil of mone than 022 percent itaiable ails or of

less than pl 630 shold be neutized before heating

Neutralization can he carisd out wing vodam

hydroxide on th has that 0 g of sian by rosige

IN:OH) will neutraize 90 2 of lactic avid, The

following example iistrates the calewaion

“Tho cheese msker wants vo race the acidity of 100

liyes of milk from 0.30 percent (30° Dorie) don to

(6.16 percent (16° Doric) simple easton shows

thatthe total amount of acid contained nthe 100 bes

of milks

0.20 0.18 = 014 49 of acs

{90°D- 16°D) x 100 kg = 1 400° = 140.9 of

cid

“The quanti of sodium hydroside necded to neuize

this amount of eid i

40x 100 = 62:2 g NaOH

Số

The procedure used for neualization i follows + accurately weigh oul the dry sodiam hydroxide + dilute dhe quantity in 0.2.0 0.5 fiwes of water:

* str mi by hand or witha mechanical agitator + slowly add the solution tò the ml, sống continues for one toto minutes

+ chock the result by’ aeid uation

Control of fat content The composition of cheese depends msialy on the total solids, or dry-matter conte, an the fa content The total solids content of 100g of cheese is reusred bythe weight of dry_mater Jef alter evaporating the water in an oven The fat content is

‘esually determined hy the Gerber method, sith the

rest expressed as «percentage of the dryer content ofthe cheese (Pox, 1987: Lambert, L088: IDE 1990)

In cheese making the fat and total solids coments

re controlled to ene standard iste and tem

‘coagulation The dey-muater content is subsequently

‘adsied hy contralling the factors regulating the Ursining and siponing of the nd (Ramet, 1985c; Rolhinson, £9905 The Fat conten inthe whole milk i higher relate tothe average amount of fat required i mst cheese varieties, Tho milk must therefore he

uviod out by nara

‘reaming or by seooping ofthe cream which hc tien

partly skimmed, This may be

‘othe top ofthe rier i hs stood fora fee hours

at oom temperature A more efficient method is separ off called amoant of eream in a milk sontriag, This is known ay standuedizing and as he catried oat either by continuously separating the caees fat or hy hatch process, mixing calculated

‘amounts of whole an skimmed iki the chee

“Ve amount of ft required inthe standardized ilk

fs caleulated as follows FSM! = (FMC x G) + FM

SNFC Fat content of standardized mi

TMSM FMC = fat coment of cheese (poreemage dry mater [SNEC = non-fat solids conten of cheese (pecentaze dry mater

G= evelliciem of recovery of non-fat milk solids in cheese (ite)

TA 1 content of whey (git)

Example

The cheese maker wants to standardize the fat

omen af camel milk to make achsese with 40

fat in toa solids, Other information required for the

Barch ri (shoe to skimmed ih)

‘hola mie ¥ 900027 = 70 ros:

‘skimmed rik 100 705 = 205 ses

‘subtract from the skinimed milk quantity the

‘volume of Figuiktie starter to be inoculated into

the milk for coagulation:

900

accurately measure the volume of whole and

skimmed milk into the sats

eazeilly stir the beh to obtain uniform milk

composition

[Correction of dry-atter content

(One ofthe most cial factors involved in processing

el nil into cheeses ts ow tla slids coment and

‘nique casein and calcium composition, fn paste, tis

possible to use comeetive methods, singly oF together,

to prepare the milk For praessing into chasse

Increasing casein concentration Diternt techniques

may be used 10 iorease the reatve concentration of

sein in ik, The aim 8 to redace coagulation me

sun improve the feological properies of the cunt

Evaporation of milk n principle, the method consists

fof concentrating the dry matter in milk by patil

tevaporaton of water In ender to aid the damaging

effects of high Heat on curd cling and draining (see

Mik preparation on p 18}, low temperatures (5 10

460°C) should be maintained, Such operations my’ Be

faricd out at the household level at atmospheric

ressure in the open ín small commainers AC the

indus level, vactom evaporation is beter, because tenable hier outputs, imposes yields and reduces ost In both cases, the optima concentration is

& 20 percont otal mail: sods hotween 15

"1 nore advanced procedure for concentrating eassin in Ink, Th view of IS wiespread indstral ase with 03's mi, it should he possible to raise the protein

‘onfent of camel mito Potcen 36 and 3.8 percent

No definite snformaion or practical experiences Have teen published about elation of cane milk 1 emphasized that ltfittion remains a sensitive process requiring thorugh cleaning and disinfetion procedures, complete safety in Feeding Mids 1 che system and skilled technical staf, Most of the pment curently aval on the kot has avery

high capacity and is unsuitable for small-scale provdction, For these reasons, ulation hus to be reserved for itdnsvil-eal production

Adding milk power Foifying cae milk solu wih tik powder improves the eluting Ue and cases significa inyrovement in cond mess, Camel mi can thas be processed ia a beter echnical condition (Ramet, 1987), Te amount of mitk powder tobe sled isaroun 4 to § percent Tis hardly ales the ast and fevtre quality of the cheese snd doesnot inerease the ost, Low- and medi heat powders should be use Another interesting alternative canld bo w use dry

by giơalhmMion or dhàydnHon, The technology is complex, however

rc etnies are expensive and nt real avaiable Production of powder fom camel mak has not been investigated, even on a pln scale Abu-Lehit, 1998) 1

is therefore nivale anil poser of bovine

‘origin as 1 be used The mixture ofthe 680 #ypes af ilk reves the anti of cheese made From pare canie} milk Local regulations concerning posible

milk reentates obtained

ferdion ngal tobe taken into account Adding fresh milk from other species Geogeaphical goats, sheep ze cattle a tales age often bed in

‘ssoctation with cams, The mis ofthese ana ae

‘table for cheese making because oftheir casein and

e milks with came! ail

salam content, Mixing thes has be

processing properties of came milk for cheese ming

ld trish carried out in Saudi Arabia (Ramet, 1990) and Mauritania (Ramet, 1994) have concluded

gaested as @ means of enhancing the

fof 10 to S0 percent has a honeficial effect pm

ation and draining

+ lowing time is significantly altered; for example

the Gime is rudiced by about percent alter

sadn only 10 percent sheep's milk (Figure 10

‘urd firmness, measured by cipiical and

instrumental ethos, s doubled alter ading only

Ho percent she’s ni (Figure 1

+ cud desing

of whey equal © $0 percent ofthe processed milk —

18 reduced by about 20 percent after adding 10

percent sheep's milk (Figure 12)

+ ity development is accelerated after ung 10,

perce sheep's milk (Figure 13), whieh reduces the

butfering capacity ofthe mix compared with camel

ilk alone

the ime needed te obain a volume

‘the recovery sate of milk solids inthe cheese is

icing camel ik With 10-10 30 percent sheep's mill, recovery

significantly inseased: ater e

reaches 42 an Sb percent respectively insted of

only 37 percent forthe pure camel milk conto

(Figure 1: Table 12),

‘The postive fees on coagulation and draining are

explained by the improved curd stctre resting

From the igh solid af sheep's mill (28.9 percent) and

lodting motrials (casein insoluble calium) Mixing

sheep's milk with camel milk brings considerable

benefils tothe processing of camel milk into cheese

‘oven when small amounts ate sed The simplicity of

the method makes it very easy 4 ¥se om both the sll

sind the instil scales Assisted howe, homeo the

dt loses ils intent a pare camelsnik preduet

asresul

Salt balance correction

Adding calcium sets The presence of enc clin is

‘eset ormplte the secondary phase of the ltt

cin micelles process and to site the network of

Feang to curd formation (see Enzyme coagulation on

p11; Wehb, Johnson and Alford, 1934: Ramet, 19SShs

Eck, 1990), Because a unigoe st folanee eis i

camel mil, the ation of @ soluble casi st, sch

asa chloride or monophospiie, produces a significant

reduction in eloting time and winfores gel seat

Rum 198Sb: Ramet, 1987; Rane, 1990: Ramet

19042), The postive fen ofthese als is expand by

the consequent pH decrease (Figure 13), which

enhances the proteolytic activity ofthe mill-leting

fenugines aul by the fet that enrichment in ealcium

ions generates sional links, which strengthen the

‘obesion ofthe easein micelle nowwork (Figure 16) Depending on the caleium salt concentration, the effects 151620 percent hher i camel ik compared with cow's milk Calcium smonophosphate 4 move ficient than caleium phosphate Ramet, 19850) From practical cheese echnolozy standpoint the alton of

ia sas has to be limited 10 10 6 15 p por Hb Ties of ik o aid development of sop’ and bitef Flavours, These amounts rede eloting times by 220

25 percent compared with cot milks Rat, 1985 Fora and Bachmann, 1987: Ramet, 1990; Ramet onda,

In onder to ensure wniform dispersion ofthe alia sas the ik ad to achieve the eqaied change in salt ala, the calvin als have to e add st east

Mi minats fore dhe ills closing enzyme tis eal time is observed, the ealeiom salts have less inlacnce

‘om eagulation Mohamed eal, 1990) When smh is heated at the beginning of the manyactring process ta improve cheese quality (sce Heat treatment on p 18), the caium sis must be

‘nk tothe milk aller thermiging or pasteurizing and sobscquent cooling to slotting emer, The kod salen salts will otherwise be prsipitated and tei enhancing effet ls

The cali sls mast be of food grade to avoid ad flusours and toxie eninerals in the cheese, For this reason, ontetinad aks should not be used, Calum cilloride of cheese-making quality is readily: and hhaply alle om the mathe in died form ipower for granules) or as an agusoas concentrate (S10 git) Caleium monophosphate should be sat in powder firm, has wer solubility anda higher pce than

‘atm chloride ands ot 0 eaiy swale

15 percent forthe cousulation process is ubtaned for remet and bovine pepsin coagulants Whon súng poteentages are ahove these sais, cleing times ae inceeased, AL ates over 06 percent NKCI, coagulation longer thin for unshod eonto! milk (Ramet, EL May und Weber, 1982; Ramet a PEMaydi, 198)

‘The positive effest of sodium chloride at low

‘somcentrations is explained by the reduction in pH,

Which enhances action, A higher

concentrations, sodium cloride has mainly

issociaing action on cassia mcelles and enzymic

proteins the salting cut effet), which adversely alests

rd formation

The effect of sodium ehlevide on cow's milks not

the same in the presence of different ¢ypes of mi

cloting enzymes (Hanily an Edelsen, 1910: Ramet

and EkMayda, 1984), A simile station fas been

found for camel milk, Bovine pepsin appears tes

sensitive (© NaCI than al rene, partial at high

concertratons (Figure 18),

The hcologieal properties of gels areas intend

bythe presence of seam chloride inthe same manner

as clotting enzymes AL the lowest concentration,

firmness is improved and britleness reduced AL

medium and high concentrations, the effets are

—

nd case a dctease in gol srength and an

in ritleness

These changes are more

significant for calf rennet than for bovine pepsin

{Ramet, 1990),

Soting camel ik a concentration of 3 percent

ray thus be recommended 1 impose eloting, The

honetit is linited in prasties, owever by the Fat tha

sodium ebloideincrases water tetesion in ead ad

redaces draining aby, Tae mea ca therefore only

be use for proton of moist cheese and some Sot

‘thsse (Rant, EL Mayda and Weber, 1982; Ramet and

EMaydi, 1984, Ramet, 19880) Whey drained trom

led curd conti about § gre of xodinm chloride,

‘shich shoal not fet its economic valu

‘COAGULATION

Choice of milcclotting enzymes

Expenmenal work in Saudi Arabia amet, 1985

Ramet, 1990) and Tunisia Ramet, 1987) hs shown tha

Aisferentcosmmerciat mulk-tosting products do ot all

have the sume ability to coagulate camel milk (Fi

2), Ofthe enzymes, bovine pepsin hasbeen ident

the best for cling camel milk Calf rennet and mai

cloling enzyme extneted from the mould Mucor

ited have slighly less effect Other observations

(Gas, Miu and Adia 1969 Yagf, 1982: F1 Abs,

1987 EL-Bata, Amer and Thahim 1987) coroborle

the advantage of pepsin for cougutting camel sik

Acharueteistic common all pepins is tha they ae

more ative than chymmosin and rennet in acid media

Cning sti decreases rapidly at pH level above

163 Atte pH of tres mit (6.65 0 6.75,

ot occa Sim Iohaviour hs been observed in both toting does

cow's and camel mi Figure 19) Ress indice that

Ae milk most be acidified to pH 62 10 5 prior to

"pgulation in ero acieve the est fos Kt be rote, however tha such an increase in aciity li

in demineralization of the casein micelles, which in tur

Inreases und frilyy and makes draining: mose ith

processing int fes ad so cheeses can be asks ult For these reasons, milk to be used foe

as describ above, For semi-hard und hard ehsescs issalvisible to init acid deselopment in ration tothe total soli ansipate in the hese to pl 641065 for semi-hard chaese and pH 65 to 66 for hard cheese, Pepsin has 2 high non-specific peoeoltic activity which may peice iter peptises inthe choose during ripening depending on the amaunt oŸ reuhal mhÏk lowing eneymes, This is tse eonitined by the pH

“The biter peides mainly riinae From betweasein

ilk

Idols, whieh is eekaively Nigh an ca

‘Obveevatons indicate, however, tha th hikemess i o> more common sane cheese than cheese made From eer ai

No definite information exits of any eactions tha

‘ould nic de se of pepsin to produce camel cheese Calf renset and fungal protease fom Mucor mie dle lor sks and could thus he prefered Uo pp,

in ite of tir veaker abit clot camel mi

Reducing al Milk-clotting enzymes are ackd proteases whose psa etsy is generally close 10 pH %5 (Ram 19854; Eek, 1990), From he Herat, appears hat fresh eam milk pH varies fairly widely fom 6.55 to (685, depending on origin and val produston factors {Fach 1993, Jali, 199%), These pH values ate not Priticuasly suitable for good clotting

enti cheese making oi the milk sighủy athe time of ang enzyme I ean be demonsrated {Figue 19) sha ineessing milk acai trom pH 6.66 0 {6.40 decreases the cloting tin By 28 percent when using tenet and 70 percent, when using hovine pepsin, Varios proceres can be used ( rhice pH sal

Was thus

«The simplest method consists of inocdlaihe the

rk sith 1402 percent etic tater culture with 2

ity of 0.8 percent This reduces pH by {6,10 100.15 pH units this reduction i 00 smal

the mi should be lft at 28 0 38°C for father aid

evelopment by the lactic acid aetria The

Fipenng time may bo incresed by 3010 90 minutes

depending on starter activity and the aciaity

regu the tar of egulation,

+A second widely use method eases pl by

means of calcium or sodium sats The dosage ates

are motioned in Salt bance corection on p21

> A thi mts to akd an exter ganic ai fo

the milk Acids with song, distinctive Mavours

(ctr aid

lowe conenations, Porsgnie lacie ack est

suited for adjusting pH Pouring must be cated ut

slowly whi the milks being vigorously stirs I

este aod, et) shouldbe used only at

the turbulence is mot steong enough, casein

Ittciplito tthe point of pouring the aid ino the

fk, The city

uring dosing to achieve the roquited pl or 11 mus he checked regularly

sieatabe ait

When fod- aad ac is not avaiable, an alersatve

retical method could be used whieh insoles aking

acid whey (1210 8 percent acti aid) abaine trom

proviogs choose making Prior ta aking the ac th

the enistng Ice ae hactria present in the camel

ilk should be destroyed by pastcurizing at 7210 16°C

for ane minut to prevent excessive goth daring ie

processing This procedure cies the conceteation of

{he milk components, howescr, so it mis he Hed

Indusikied counties, The frst aviiies the milk

‘vith ehaconic acd produced from agueous hydrolysis

gf gieo đela-ladone (GDL), Thờ seeonM s based

‘the forifeaion øểcubonie eidin ml by ijsetin=

purtiod carbon dioxide The gs ready soluble and

induces rapid pl de

Increasing acidity generates

demineralization af the casein micelles in addition to

the pH decrease This development, int

sradual decrease in cud chastity ad desing ability:

‘The reduction of pl must therefore be cared out with

can ng thề nano, wgl-lelined linnts foreach

a corresponding

chat tin (See Summaries 0n p 28)

Tn some Affican countries milk including camel

rn, is stored in wooden containers, which are scoured

With charcoal or heated over am open ite Uses tha

‘his out cause small decrease in pH oF 0.1 2

pH units) resting from the dispersion of engi aids

in he milk, MiK treated inthis way, ad the reslant -ehvese, havea chaniceisic smoky’ Mavour (Mohamed, 1990; Ramet, 1995),

Increasing he cloting temperature The optimum temperature for most milk-cloting enzymes is around 40 t 48°C Abo this range, the

‘enzyme is progressively deactivated up 1 65°C, shen denaturation is total (Ramet, 1984, Eek, 19%, Đelseen 25 and 40°C a linear whationship exists hotween femperaure increase and the reverse oF loti tins Using rent asa coagulant, foe example

"9l đeensee the clotting time of 0's milk by about nh "

ey with earpel milk, but the

nt (Farah and Bachan

‘There isa simi tende crease is mite 10 $0 per 1980),

In prostic, it posible to capaize on this property

The possibility of increasing emperarre i Feasible hratonly by 840 5°C

Increasing the amount of mi lating enzyme For most miesfetting enzymes, a inear eatonship

‘evislshotwcen eon time and the reverse of enzyme

‘eancetation 1 fe mount of enzyme is doubled, the cloting time is rednced by half (Ramet, 19850)

sd with cae,

naetice this aljustment shouldbe emo hecaune altering the enzyme concentration upsets the delicate balance hetwoen acd and enzyme wakeup, Which defines any cheese-making process Oxerdoxi fof the milk-cltting enzyme invariably causes ki

opment of bere resting fom accumulation of bitter peptides lar eur texte ad the de

À Íudher consideration i) Timuting enzyme

‘concentration is thatthe cling abi of camel il

is reduced mote than forthe milk of eos, sheep, goals

this sation calls

or bolle, Ax previously mention for an inetease in enzyme concentration in order 10 tain comparable processing times Is not advisable,

however, (© inorease the clotting enzyme amount

signi

DRAINING

Methods

The chet feature of the camel ilk eoagulum during

raining, even alter remedial traHtent is thất ik

‘depends mini onthe bitlenes and the low ckesticky

fof the curd Physical weatment applied doting the

catliee stages of draining should thas be euried oat

wth cae to prevent any damage and unwanted cord

Aisinegeation

‘A wellfortfied coagulum is needed at cutting,

‘which mst be done with cate These conditions are

essential (© preven the cud from disintegrating iio

‘small pariles that will be lat in the sthey, The

moulding techoigue should not cause tener curd

breakage Methods used to ensure proper draining

depend on the type of cheese to he presse:

* For soft, semicard and had Gs, fimer cud

mins are essential to ensure that hey will not he

furtererashed onthe draining surtaces by clths

‘maul or plates, The sizeof cut ofthe cued grains

fs thus fo reduced compared sith cow's milk

cd to ensure production of standard cheese, The

curd rains should be left to whey if fora anger

Pesca in the cheese vat Hoth these processing

‘modifications prodoce a significant norease in the

total solids of the cunl, which reinforces the

cohesion of the casein network (Ramet, 19853;

Ramet, 1991; Remo, 1990),

For fresh cheeses with a water content of more than

65 percent and high eur fragility zee illing ino

hese moulds is difficult because of high cud

losses through the holes onthe hottom ad walls of

the moulds In onder 10 avoid these unwanted

fleets, the cư should fest be deine 48 muslin

cloths or bags Muslin ensures good cut retention

and whey filtration, Two to thước hou hiến

Imoukling of the putally drained curd can he

canied out thou fumber excessive cud losses

(Rant, 1995),

“These meuifiations are particularly calle for when

the mith to be processed has lo toa solids gontent,

This situation cecues often in the hot season when ilk

is collected from animals under feed and water

Frndship (Ramet, 1990; Ramet, 1991; Ramet, 1994b;

Ramet, 1995),

Afr moulding, subsequent drsining of camel mk

cond is eharacterized by several distinctive features

“Large amounts of cunt soon sick to th dining surfaces, cloths anal mas, To prevent th te Fist turing of te cheese mold mist be doe a soon as Possible, preferably within 1 to 8) mites of filling The sovond tring must be cased out 3010 {60 minites later: Inordero reduce curd sticking and

«ensure better whey seepuge a god solution ist put

‘as akdtional cloth (cotton tarban elt, curtain lodh etc.) the deaining ma removing iar the second turing (Ramet, 19946; Ramet, 1995),

‘Compared wi the draining of cunt trom other nik, wheying off eamel milk cord is much faster

‘Whey’ drainage is geneally complete within six hours of moulding, When draining is eoatinned for futher 1610 24 hones using the common metho for other milk, camel eleese becomes very dey, with «ard, chalky texture ‘The higher water soNent of camel mik and the reduced water binding abiey of the cesin are probably the cases To avoid this, cheese-making techniaues that reduce wheying off should be used, sash 2s lowering the temperature of the draining roam oF reducing the aumber of turns and the level of acidity I mast he stessed that these techniques

owed to init acid development and henge the offec of pH depression inte cheese,

ao much (Ramet, 1990; Ramet, 1995), Some ofthe techniques proposed to improve the eoagulation abihiy of camel milk, such as heat weatment oF

‘avihnent with whey preeins, have the secondary clfect of inseasing curd hycation and slowing down whey druinage

Ate end of draining, the absorption of sale into

should not be

‘ame! cheese is mach faster than ita cheese mae from other milk (Ramet, 1987; Ramet, 1990, Ram, 194) Asa rest ees entre becomes Jha ad the taste too sally It appears that this

‘original effect could be the result of several factor,

‘sch as ower fat conten resulting fom high at loses inthe wey a weaker casein wate-hinding capacity and larger micelles Ramet, 9045 Ramet, 1995) In exer to avoid these defect, the amount of salt to he sled fo the chvese must be carefully checked It is preferable to sat by dipping the hese in brie, The exact sal evel can then be accurately deveined by regulating the time the cheese is in the sak bath Compared with similar

ch reduced by aboot hai for soft cheese (Ramet, 94h; Ramet, 1995),

made trom cow's milk the salting tie is

‘he sets f mang chee cae mil

cheese yield

Cheese yields under experimental cheese-making

conditions indicate thatthe gevonery of milk solids i

the cheese depends largely on ilk origin and choos

season from milk with & poor dey-mutier content, the

percentage of solids recovered slow (31,7 pence) and

Similar tthe level measured withoot coeretive

treatment (Ramet, S87} When core

such a pasteurizing and ang cacivm salt are uses

‘on mk from intensively managed animals recovery is

improved to 48.7 percent (Table 13),

For sft cheese made from mil: preduced by camels

managed under extensive systems, solids recovery

‘ares fom 38.0 percent al the en of the et season 1a

42.0 percent at the beginning of the cold season

Ramet, 1994; Ramet, 1995) When camel lk is

enriched with sheep's milk at rates of 300 and 500

percent, recovery is geal improved rom 33.3 percent

0 $5.1 and $8 percent spectively

‘The recovery of dry mater in fresh cheese is Wher

thar in other cheese, mainly hesase the whey solids

re more strongly held in the cur, For example, when

ccamol mith is prosessed after pasteurization an!

ation of mositiod mitk-loting enayme ad ealeium

salt recovery reaches 560 percent (Ramet, 19944)

The weight of cheese predced from 100 lires of

rik is dependent on the mostre coment of the cheese

ad the level of recovery ofthe lk solids, On ave

the yield Yor semi-hard and soft cheese some 10.5

107kg per 100 litres of milk when the milk solids are

high (Table 13; Ramet and Kamoun, 19NS: Kemet

19940), When the quality ofthe aw mi spor, sete

esreane markedly to as low as 6.7 percent Ram

ON For fesh cheese made trun good-quality ilk

the yield eeaches 2600 percent (Rant 194),

whey

Whey’ deained feom carmel milk has & charwcerstie

white colo total sls content averages 63 10 7.0

percent of whieh 12013 percents Fat Ramet, £987,

Ramet, 1904}, The amount af sli loss i whey ca

the reduced ducing processing by using milk with high

total solids and being careful with mechanical

tweatment during clotting and draining Te flration

foe at draining greatly influences the solids losses,

With higher rates proucing beter recovery an lower

fat levels of around 0.6 percent Ramet, 1905)

“The tại amount of whey produced daring drning

Js mpomtant I varies asthe reverse of cheese weight

sand comprises beuween 70 and 90 perwent of the

“quai of processed milk for res, soft and seman cheeses, espetively

RIPENING

Date on the ripening of limited, becanse bile scieniic research has een "` samel out ino this relatively new subject Only sonora observations have been made daring teas on Luray or pio scale Very ltl speetic information

hs been published on eipening cme

‘compositional factors regulating enzyme potetal or The changes in cheese composition caused by the Fxperimental resus indicate that taste and texture quality develops in a similiar way to cheese produced from cow’ mils i important distinction eoncers the

‘development of a more crumbly, chalky eheese texture

“These properties re probly the resi ofthe Tome at samem and reduced waterbinding capacity of the asein, Another factor, which fas aseasionally been reported when the cheese is consumed, is a greasy sematton in the mouth (Ramet, 1987: Ramet and Kamoun, 1988: Melia, 1994), This dest is assumed

to originate fom the fally aed competion of cane

‘vith fal ahd fom interactions iavolving mouth temperate and the meting pot ofthe fa

For cheese ripened forse

days inthe open at ambient tempers, water evaporation fromthe curd thsper ad fis in camel mitk cheese than in cheese fro osher milk, These developments led lo te Formation of cnistysurace an hurd ext whih ae rahably linked 10 he speiisefeets of ft and essen

‘sic Fiat the migration af five water towards the strong atmosphere As eamel milk cheese is more sersiive to water Balance, the relative humihty of the ripening room oF eontainer must be accuntely sono at bexween MO and 95 percent Such soir diffe in dy ever environments where the humidity {soften a low as 154920 percent (Ramet, 1995), Another important factor is that the growih of

‘microbial flora involved it pening # termined by water activity (AW), mainly on the surface of the ese [far humidity drops below 65 percent, surface water activity saiizes at 0.65, siting developmen

of microorganisms according Wo thee sensitivity 0 AW

“The development of cheese competion and taste quality ceases and ripening doesnot progress normaly For choese that is mainly ripened by fa

composed of Penicillin camembern, Peniitlivn

ora

quer and Geonrtchunn lass the visual owt ad

appearance of the mycelia have heen judged

sallfactory for various iypes of chooses such as

Camembert (Ramet, 1987; Ramet, 1990: Mehais

1994; Ramet, 1994: Ramet, 1095), fesh cheese

(Ramet, 1987) and semi-ban cheese (Ramet, 991)

Ôn seme batches of hard

development of the micofira has be

rot byen clculy determined whether dis originates

from the effect of ater astivty or ftom residual

activity of the strong antimicrobial eapacity ofthe ra

‘ame! mik (Ramet, 1994; Ramet, 1995)

“The taste of cheese me from came! mk varies

cheese, slower ote has

according to Fipeing te and cheese type, Fo [nh

cheese consumed immediately afer draining and

“ung without ripening the taste profile is reat

Without any distintive charters For youn soft

cheese and semi-hard eheese, similar resus have been

Found (Ramet, 1987: Ramet, 1984)

For sot cheese ripened with Peni camembert

a the dominant ore, a distinctive, exiginal tse

Abevelops with im al ansformation ofthe ond occurs This avout, which is completely ferent from similar cheese made feom cow's mil, is azcopted posivey hy testers (Ramet, 19940, Ramet 1995) [Aslight to moderate hitemess has sometimes Been rote in all hese types during the carly sages of Fipening, This generally disappears as ripenin develops, The origin ofthe deet bas not been slaty Aienitied lieould be auselhy the effect of igh evel

ff calcium salts ws for improving the coagulation process andor the accumulation of biter peplides formed by residual proteolyie aetvity of the ih slotting enzymes anl the resaant lowe pH valve (Ran, 1987; Ramet and Kamoun, 1988; Kamoun and Bergaoui, 1989),

“The salty andor biter uste sometimes detected in some barshes of camel milk choose originates fron

¬ thas aot been determined

‘The choy af mang cheese fn cnet

Chapter 4

Methods of processing camel

To produce high quality cheese i #8 necessary to

follow rostine practice sonnet the prediction ofall

cheese types Only the basie tops are outined below

For more detailed information, wferenee shld be

‘made to specialize publications a the subject (Als

1984; Veiseyee, 1975; Rams, I9SSe, Seat, 1986 Fos,

1987; Robinson, 19909; Eck, 1990), Later i this

hapler, processing methods far thế mam Iyps of

‘camel milk cheese are sommrized,

GENERAL GUIDANCE

Basie mile proces

To achieve a gond-quality product,

recommenditons should be followed the ollowing

‘select milk with good chemieal and mirabiat

ina clean, dust fee environmen

‘use properly cleaned and disinfected wtensits

‘employ health clean tine sta

+ enhance the processing capability of eam milk

‘ase only additives dactie starters, mithcloting

‘enzymes, sis ee.) of fone grade std with

Properties + store heat sensitive additives under eigration to

lint ato

+ keếp pershah

products under cool conditions and protected ro

Tig stand rodent

catment such as heating andioe

Milk

and calcium salt (se

Preparing and using late startors

Using the rit late starter ensures authsntic taste and

hygienic quality Forchese mde from rss ilk te

star audition is reeommended boost the moral

population of lactic aid hyeteria and inhibit afl

milk into cheese

Moxa such as coliforms and psycMokaphie and pathogenic hisieria, For cheese mia fom heated

it, Htc ster dition i mandatory 19 develop proper ait da

sr, Lactic starters ean be prepared by Simple methods

household oF for andustal prevhition, The revommended method of preparation

tnd ei preservation of the

adapled either for i848 follows

"` ố rnilk wth good bcteidlogiedl and chemical quality

‘oF pesonstted nik obtained from dissolving 10 event skimmed milk: powder in potable water:

* pour the reconstiuted mith do conbiners lóc

steization lize the milk 100 t0 120°C for ten to 20

‘cool down to the incubating temperature

‘ingot the mill under aseptic condos with the

mother culture at the mate of ether OS g of dry ature por 0.5 to Ft, oF 20 el of id ular pert 0 1 hte

‘incubate im an incubator or at coor temperate risophibic starts st 25 10 35°C for eight co 12 hours theropilie starters at 42 10-45°C for 149 9 four hoes:

‘halt incubation whe the acidity reaches 0.7 0 0 erent late acid of pl 50 to 55

‘cool doin and hoep the starters under erperte

‘conditions (0 x0 4°C) ai ws + avoid long so

——

“Rap thế temperatures (4010 80°C)

pods, eich ede lati aid

"` feezet

‘Adding cheese-riponing moulds Some types of cheese are tutionally ripened with moulds that do op either on the surface (fresh, so tnd some semictard cheeses) or in the body oF the cheee (Me elseseo), Tradionali, the uptake of moulds eccues through natural inoculation when the

choose i eft ou in the siping room, which is fall of

spores, This meted Js risky, Rowover, and cagses

‘consistensy in appearance and taste ofthe cheese, I

Js beter « use a mare contlled inoculation of

commercially available complementary exogenous

calles, ovale in died or Higuid form,

“The dominant organisms in the surice Mora are

‘teins of Pencil, Gevsrcluon an, occasionally,

Mucor These moulds ar often also associated with

yeasts and bacteria, Peniclin cxamembert is widely

tse and gives atypical white appearance to many soft

cheeses, suc as Camembert or Brie, an some smi

hard cheese such as White Tore

oquefor is the typical mould that develops in ue

sovwing im the holes in the chee

Inoculation of spores is cate! out hy two msthos

‘in the milk prior to coagulation by mixing ám

appropriate quantity of commercial stains,

E sure of the siltd cheese, either by

soaking ina solution of spores in serie water oe by

spraying the solution over the whole surtace

EEquipmont used fo ineutation mus be thoroughly

cleaned and disinfected t avoid contamination by

spoilage organisms The spore concentation is

ajusted according 10 the method given by the

manufacturers

Because the moulds sed in cheese pening re

highly aerabic, the cheese i placed on tays oF wooden

boards which allow good sl-round surface aeration

During ripening, the chsese is regully tnmed 10

emame even growth of the mycelium Oder

‘vironmental factors aso need tobe closely sepulted

‘0 optimize mould development The temperature is

wesually set between 12 and HỨC, except for bloe

fees whem i is set a 6 1a 7°C The relive hamidity

Pencils

ud,

is set between 85 10 95 petwent, depending om the

sensitivity ofthe microflora to water aetvity Under

1 mould growth is Qui rycolium becomes visible after four 19 i days fll

development takes upto 15 4 25 days,

The proeolyic and lipolytic potential of mouk!

enzymes is important and influences significant

biochemical changes in the composition and taste of

the cheese

‘dese condition sow, The

Characterizing and using mlleclofing preparations

The activity of commercially avilable milk clot

reparations is determined in cheese making by

clolting strength, which corresponds 10 the ratio

hetween a defined amount of the preparation (une

fo liquid prepurations, weight for dried preparations) and a defined amount of milk to be sftted under precise time-temperatore conditions The standacd reference used in Europe ingicates that t kg of poskered rene, labeled with a strength af 1150 000,

‘ill coagulate [50.000 fies of mit a 35°C within 40 The sirens of Figuid preparations dectines slowly a ambient temperate (1S fo 43°C) and refrigerated

‘storage (0 to 6°C) s recommended Dred preparations are les sensitive, but refigeation & advisable for prolonged periods of storage

"Tho eesuls indicat that camel milk is not readily processed into choese compared with mil from other

‘hy animals This results mainly fom its low wt solids content, unique composition and cascin properties Its suitability for cheese making decreases Sgnifcanly in the hoi season, ashen camel mike rection is ifluenced by water and feed avila

‘The summaries have been modified (0 cover processing of poor-quality milk Ist recommended thai bi hơi rolmenl and cal iu salt enrichment be

‘employed, To effect the changes et outin Chapter 3 the other conetise steps may’ be applied Is als crucial

Tức kelodop of mang cheese rom coe mi 2 Fresh cota) cease

Seat — ane “Heømnaamr igo em 1 ig a eT TON

Seg a a SE ae RIT (aia ne ‘Systane TP aes

Gana crane ae a Hal opr

sean