2,4-D Selective systemic herbicide used for post-emergence control of annual and perennial broad-leaved weeds in cereals, orchards, some vegetable crops and sugar cane.. Dairy starters
Trang 12,4-D Selective systemic herbicide used for
post-emergence control of annual and perennial
broad-leaved weeds in cereals, orchards, some vegetable
crops and sugar cane Classified by WHO as
moder-ately hazardous (WHO II) Also known as
2,4-dichlorophenoxyacetic acid
Dab Marine flatfish species (Limanda limanda) which
occurs abundantly around the northeast Atlantic Flesh
has firm texture and a sweet flavour Marketed
fresh, dried/salted, smoked and frozen
Daconil Alternative term for the fungicide
chlorotha-lonil.
Dahi Fermented milk product popular in India Dahi
made from buffalo milk is generally preferred to that
made from cow milk A sweet variety of dahi, misti
dahi, is prepared by adding cane sugar to milk
dur-ing heatdur-ing, givdur-ing a caramelized flavour and brown
colour.
Daidzein One of the two isoflavones of particular
importance in soybeans, the other being genistein.
Both compounds are structurally similar to oestrogenic
steroids and possess both oestrogenic activity and
anti-oestrogenic activity, the principal functions
re-sponsible for the health benefits associated with
con-sumption of soybeans and soy products.
Dairies Premises in which dairy products are
manu-factured Also called creameries or dairy
Dairy beverages Drinks based on milk or other
dairy products, e.g whey.
Dairy desserts Ready to eat desserts based on
dairy products, such as cream, milk or yoghurt.
Available as chilled, frozen and shelf-stable products
Include mousses, custards, fromage frais, milk
puddings and ice cream products
Dairy factories Premises in which dairy products
are manufactured Also called creameries or
dair-ies.
Dairy-lo Trade name for fat substitutes composed
of whey protein concentrates which have been subjected to controlled thermal denaturation, result-
ing in functional proteins with fat-like properties Used
mainly in reduced fat dairy products, frozen dairy desserts (such as ice cream), bakery products and salad dressings Marketed by Cultor Food Science Dairy products Products manufactured from milk Include as major product groups, cheese, yoghurt, butter, cream, fermented milk, ice cream and whey products Also called milk products.
Dairy science Division of food science dealing
with the characteristics, manufacture and quality of
dairy products as well as the production,
manage-ment and distribution of dairy animals such as cows, goats and sheep
Dairy spreads Spreads based on milk fats and
containing other, sometimes non-dairy, ingredients to
give a lower fat content than butter.
Dairy starters Microbial cultures used in manufacture
of fermented dairy products, including mented cream, fermented milk and cheese Dalia Types of porridges made from wheat grits ȕ-Damascenone One of a number of aroma com- pounds found in plant foods and beverages pro- duced from them A member of the ketones class of chemicals derived from carotenoids and has the mo-
fer-lecular formula C13H18O May be added to
flavour-ings, but more commonly used in fragrances, being a
characteristic aroma compound in rose oil Imparts a
floral, fruity or woody aroma.
Daminozide Plant growth regulator (the active
com-ponent in Alar) which has been widely used in the
cul-tivation of apples Concern arose in the 1980s over
the safety of Alar when it was identified as a possible carcinogen Daminozide is also known by a number of
other names, including N-dimethylaminosuccinamic
acid, kylar and SADH
Damsons Purple plum-like fruits produced by
Prunus damascena Eaten cooked or used to make
jams or damson cheese, a solid preserve of damsons and sugar.
Danbo cheese Danish semi-soft cheese made from cow milk Has a smooth, dry, yellow rind and is
Trang 2sometimes coated with red wax Ripened for 6 weeks
to 5 months
Dandelions Common name for Taraxacum officinale.
All parts of the plant are consumed The root is used to
make beverages that smell like coffee but have the
flavour of chicory, the leaves are used in salads or
as vegetables, and the flower heads are used in
wine-making.
Danish pastries Sweet bakery products made
from laminating yeasts-fermented dough with
but-ter or margarines and filled with nuts, fruits or
custards Often glazed with thin sugar/water icing
Dark chocolate Chocolate that contains at least
35% cocoa solids In the US, both semisweet and
bit-tersweet chocolates may be referred to as dark
choco-late An equivalent term is plain chocochoco-late Dark
chocolate is a rich source of gallic acid and
epi-catechin.
Dark cutting defect A defect of beef, often
associ-ated with bull beef Dark cutting meat, also known as
black beef or dark cutter beef, has a darker colour,
and poorer flavour and texture than normal beef;
moreover, the high pH value of dark cutting meat
en-courages the growth of spoilage bacteria and reduces
shelf life Physiological stress and exhaustion
pre-slaughter deplete muscle glycogen stores, ultimately
increasing the pH of meat and leading to the
develop-ment of dark cutting defect In young bulls, incidence
of dark cutting defect can be decreased by low stress
handling and prevention of bull behaviour (mounting,
mock fighting and butting) in abattoir pens prior to
slaughter
Darkening Discoloration of a substance by
becom-ing dark or darker Red colour is often used by
con-sumers as an indicator of the freshness of meat
Darkening of the product, which occurs during storage
due to pigment shifts, is perceived as being a negative
event, even though this is not a true indicator of
whole-someness or nutritional value Because of consumer
concerns, packaging films are designed to protect
meat colour, largely by controlling diffusion of
oxy-gen Darkening is also a problem during repeated use
of frying oils.
Dark firm dry defect Commonly abbreviated to DFD
defect, a condition associated with pork in which meat
has a high pH value and darker than normal lean
col-our The defect results from a decreased glycogen
content in swine muscles prior to slaughter; it is often
associated with pre-slaughter stress In beef, the term
dark cutting defect or dark cutter is used to refer to
the same condition
Databanks Large stores of data held on computers
DATEM Anionic oil in water emulsifiers used as improvers in breadmaking Acronym for diacetyl
tartaric acid esters of mono- and diglycerides
Date marking Marking of food or beverage containers
with a date that may be the date of manufacture, the sell-by date and/or the use-by date (expiry date) The sell-by date is the date by which the manufacturer rec-ommends that a perishable product should be sold Use-by dates are chiefly used in the UK instead of sell-
by dates, and indicate the recommended date by which
a perishable product should be eaten or used, after which it is no longer deemed to be safe, desirable or effective Date marking is often required by law, par-ticularly on packs of foods which should be maintained
at low temperature, e.g cheese, pates and ready meals, and on foods in which spoilage organisms
are likely to multiply or cross contaminate other foods,
e.g fresh meat and fish Other foods, such as bread and cakes, which tend to deteriorate in quality rather
than safety do not require date marking by law, but are often labelled voluntarily by the manufacturer or re-tailer
Dates Fruits of the date palm (Phoenix dactylifera).
Vary in colour, shape and size, and may be soft, dry or semi-dry Contain high levels of sugar, amounts and individual types of sugars varying among cultivars, but
small amounts of vitamins Vitamin C content is
relatively high in fresh fruits, but is reduced to trace
amounts by drying Served as dessert fruits and porated into many food products, especially cakes and biscuits In addition, in Arab countries, dates are also used in preparation of syrups, vinegar and sugar substitutes.
incor-Date shells Marine bivalves (Lithophaga
litho-phaga) occurring along shores of the Mediterranean
Sea and eastern Atlantic, which bore into rocks using a secreted acid Consumed as a table delicacy in some Mediterranean regions
Dating Process of marking a product or its outer
pack-aging with date information, such as date of ture or date by which the product should be consumed
manufac-to ensure quality
Davana Common name for Artemisia pallens, a plant
used as the source of aromatic herbs and essential oils with a characteristic fruity odour Used in fla- vourings for cakes, pastries and value-added beverages.
Dawadawa Fat- and protein-rich fermented foods
from West and Central Africa, traditionally made from
African locust beans Seeds are cooked, fermented
and formed into balls, which can be used to flavour
soups and stews The fermented products can be stored for long periods and are a good source of li-
Trang 3noleic acid and vitamin B 2. Also known as iru in
Nigeria
Day lilies Plants of the genus Hemerocallis that
be-long to the family Hemerocallidaceae Some species
have edible flowers, which may be used fresh or
af-ter drying, and which exhibit sweetness and a mild
vegetable-like flavour The young green leaves and
tubers of some species are also edible
DDD Alternative name for TDE.
DDE Persistent non-systemic organochlorine
insecti-cide occurring as a degradation product of DDT Usage
of the parent compound to control insects on crops
has generally been displaced by less persistent
insec-ticides.
DDT Persistent non-systemic organochlorine
insecti-cide used to control a wide range of insects Subject
to the Stockholm Convention on Persistent Organic
Pollutants and usage on crops has generally been
dis-placed by less persistent insecticides Classified by
WHO as moderately hazardous (WHO II)
Deacetylation Form of chemical structure
modifica-tion involving removal of acetyl groups (CH3-CO-)
from molecules Used to convert chitin or chitosan
into biologically active derivatives and to alter the
rheological properties of additives, such as
xan-than gums.
Deacidification Neutralization process whereby the
acidity of a substance is reduced Deacidification is
of-ten used in conjunction with the processing of apple
juices, cider, vegetable oils, wines and grape
musts Deacidification of grape musts is crucial for
the production of well-balanced wines, especially in
colder regions of the world Malolactic
fermenta-tion is widely used to reduce the acidity of grape
juices Young wines can also be deacidified with
cal-cium carbonate and potassium hydrogen carbonate
Deacidification of vegetable oils (such as rice bran
oils and corn oils) can be carried out using solvent
extraction and membrane processing Nanofiltration
has been used for deacidifying and demineralizing
cot-tage cheese whey, ready for use in ice cream and
other frozen dairy desserts.
Deaeration Removal of air or oxygen from a solution,
for example by bubbling with an inert gas Also known
as degassing
Deamidation Form of chemical structure
modifica-tion in which amide bonds undergo hydrolysis to
remove amide groups from molecules such as
pro-teins and amino acids Enzymic or non-enzymic
deamidation of cereal proteins is often performed to
improve functional properties, such as solubility,
foaming capacity and emulsifying capacity Can
also cause undesirable damage to amino acid side
chains on certain food proteins during processing Deaminases Includes members of EC 3.5.4 These hydrolases act on carbon-nitrogen bonds other than
peptide bonds, removing amino groups from
com-pounds Ammonia is produced in the process strates include purines, pyrimidines, nucleotides, nucleosides, etc., and hence can affect food fla- vour.
Sub-Debaryomyces Genus of yeasts of the family
Sac-charomycetaceae and class Saccharomycetes omyces hansenii, which tolerates high concentrations
Debary-of salt and is cryotolerant, is the most common cies of yeast found in all types of cheese Also found
spe-on fish, in salted dairy products and in brines as it
is able to grow in the presence of salt at low
tempera-tures, and to metabolize lactic acid and citric acid.
D hansenii also provides proteolytic and lipolytic
ac-tivities during cheese ripening This species is one of
the most frequent yeast species to be associated with
chilled foods Used as a starter in the manufacture of fermented sausages, and has been responsible for the spoilage of fruit juice concentrates and yo-
ghurt D hansenii is able to convert xylose to
xyli-tol.
Debittering Removal of bitter compounds from foods such as citrus fruits, chocolate, soybeans and cruciferous vegetables, and beverages such as wines, fruit juices, cider and beer, to make them
more palatable Debittering can be achieved
biologi-cally, using enzymes or immobilized bacteria tone hydrolases are used commercially for debitter- ing citrus juices by removing triterpenes Correction
Lac-of excessive naringin bitterness in citrus fruits can
be achieved through use of adsorbents or dextrins to form less bitter inclusion complexes De- liberate aeration of the pulp during apple juice ex-
cyclo-traction for cidermaking promotes the removal of bitter
and astringent flavonoids through their binding to the pomace Fining with gelatin decreases contents fur- ther still by coprecipitation Proline-specific amin- opeptidases can be used for debittering food pro- tein hydrolysates Enzymic hydrolysis of oleu- ropein by ȕ-glucosidase from Lactobacillus planta-
rum offers an alternative to chemical debittering
treat-ments for table olives.
Deboning A process for cutting of meat from the bones, which can be done either manually or me-
Trang 4enhance milling performance of cereals as well as to
provide by-products with potential as food ingredients
However, debranning may also affect the nutritional
quality and functional properties of the cereal and
subsequent products
Decaffeinated coffee Coffee from which caffeine
has been removed by a solvent extraction process
us-ing aqueous, organic or supercritical solvents
Decaffeinated tea Tea from which caffeine has
been removed by a solvent extraction process using
aqueous, organic or supercritical solvents
Decaffeination Removal of caffeine from a
sub-stance such as coffee or tea Caffeine is removed
from coffee by soaking coffee beans in chemical
solvents or water The resulting decaffeinated product
contains approximately 3 mg caffeine per 150 ml cup,
compared with 75-150 mg for normal coffee
Ȗ-Decalactone One of the aroma compounds,
with molecular formula C10H18O2 Synonyms include
decan-4-olide and 5-hexyldihydro-2(3H)-furanone
Has a fruity, peach-like aroma and is naturally present
in various foods, including fruits and alcoholic
beverages Microbially synthesized Ȗ-decalactone is
used in food flavourings.
Decanal One of the aldehyde flavour compounds,
which occurs naturally in a wide range of foods and
beverages and is used in flavourings for processed
products
Decanoic acid Synonym for capric acid Member
of the medium chain-length saturated fatty acids
with 10 carbon atoms Found in a range of animal and
vegetable fats and vegetable oils, and, in its free
form, contributes to the flavour of foods and
bever-ages.
Decanol Alcohol with 10 carbon atoms Along with
some of the other higher alcohols, contributes to the
flavour of foods and beverages, especially
alco-holic beverages, and is also widely used as a
sol-vent
Decanters Stoppered glass containers into which
wines or spirits are decanted
Decarbonation Removal of carbon dioxide from a
sample Required for sample preparation prior to beer
analyses, such as determination of original gravity
and alcohol content
Decarboxylases Lyases belonging to subclass EC
4.1.1 that remove carboxyl groups from a molecule,
especially amino acids and proteins When acting on
single substrates, a molecule of CO2 is eliminated
leav-ing an unsaturated residue
Decarboxylation Chemical modification involving
the removal of carboxyl groups from organic
com-pounds, generating CO2 Can be due to the influence
of enzymes (decarboxylases) or other catalysts,
or can occur spontaneously Several aroma pounds, including diacetyl, are formed by decar-
com-boxylation reactions
Decenoic acid One of the monounsaturated fatty acids, having the chemical formula C10H18O2 Vari- ous isomers exist, some of which are used as fla- vourings, including 4-decenoic acid and 9-decenoic
acid (also known as caproleic acid) Also present as
natural flavour compounds in foods, including
dairy products The derivative
trans-10-hydroxy-2-decenoic acid occurs in royal jelly and is used as a
marker for this product, while another,
10-oxo-trans-8-decenoic acid, is produced by mushrooms and hibits antimicrobial activity.
ex-Dechlorination Process of removing residual rine from a substance In the food and beverages industries, chlorination usually cannot be considered
chlo-without the added expense of dechlorination, as ual chlorine must be removed to prevent chemical
resid-changes affecting flavour, aroma and colour of the final product Activated carbon is usually used in
the beverages industry to dechlorinate and remove
trace levels of outside flavour compounds from water to be used in producing beer and soft drinks.
A non-chemical means of dechlorination involves use
of a high energy ultraviolet system This cost effective process reduces free chlorine levels by up to 99%
Decoction A liquor containing the concentrated
es-sence of a substance, produced as a result of heating
or boiling.
Decoloration Removal of the colour from an item
Also known as decolorization
Decolorization Alternative term for decoloration Decomposition Breakdown of matter, including
foods, into its constituent parts Leads to recycling of nutrients and their eventual return to the biosphere Can be mediated by bacteria or fungi May lead to quality deterioration and food poisoning outbreaks Can be induced by exposure to airborne microorgan- isms, storage at room temperature and wetting of dried foods Also induced by exposure to light (photolysis) or by autolysis Can be prevented or delayed by frozen storage, drying, canning, pickling, vacuum packaging, controlled at- mosphere storage, irradiation, pasteurization
or addition of preservatives.
Decortication Removal of the outer layer from
seeds or fruits prior to consumption or further essing Also called husking, dehulling or hulling Deep freezing A method for preservation of foods by rapid freezing and storage at -18°C Freezing pre- serves foods by preventing microorganisms from
Trang 5multiplying Enzymes in the frozen state remain
ac-tive, although at a reduced rate Commercial freezing
is usually undertaken by one of the following methods:
blast freezing, where air is circulated at -40°C; contact
freezing, in which refrigerants are circulated through
hollow shelves; immersion freezing, where, for
exam-ple, fruit is frozen in a solution of sugar and glycerol;
and cryogenic freezing, using, for example, liquid
ni-trogen spray Rapid freezing avoids structural change
that would affect flavour or appearance of foods, as
in the shrinkage and distortion of cells by formation of
enlarged ice crystals in the extracellular spaces Some
quick frozen foods require thawing before use, and
cooking must then be prompt This method of
preser-vation is widely used for a great variety of foods,
in-cluding bakery products (both ready to eat, and to
be cooked when desired), soups, and precooked
complete meals.
Deep frying Cooking of foods in an amount of hot
fats or oils sufficient to cover them completely during
frying.
Deer Common name given to various species of
even-toed, hoofed, ruminant mammals belonging to the
fam-ily Cervidae The term is used specifically to describe
any of the small- or medium-sized species of the
Cer-vidae family, as being distinct from other large-sized
species such as elks or moose Deer are farmed or
hunted for their meat (venison).
Deer meat Alternative term for venison.
Defeathering Removal of feathers from the
car-casses of meat-producing birds, such as poultry,
during processing If defeathering is not performed
properly, carcasses can be mechanically damaged or
microbially contaminated, both of which are of
eco-nomic importance to the poultry industry
Defecation Removal of impurities, usually applied to
the stage of purification of sugar juices during
sugar manufacture Defecation involves
clarifica-tion of sugar juices by heat and lime The lime is
added to neutralize the organic acids present, after
which the temperature is raised to approximately 95°C
This lime and heat treatment forms a heavy precipitate
of complex composition, which contains insoluble lime
salts, coagulated albumin, and varying proportions of
fats, waxes and gums The flocculant precipitate
carries with it most of the finely suspended material of
the juice that has escaped mechanical screening
Sepa-ration of this precipitate from the juice is undertaken
using a juice clarifier Degree of clarification has a
great bearing on the boiling house operations, and on
yield and refining quality of raw sugar
Deficiency diseases Conditions arising due to the
absence of a dietary nutrient, such as one of the
essen-tial vitamins or minerals Include various types of
anaemia, rickets, scurvy, pellagra, beriberi and tre Strategies to counteract these disorders and im- prove nutrition often combine direct dietary interven- tion (provision of food supplements, food fortifi- cation, dietary diversification) with agricultural measures (development of foods of improved nutri- tional values and bioavailability, development of
goi-improved agricultural practices) and economic
meas-ures for improving food security.
Defoaming agents Substances, often silicon-based, used to minimize formation of foams during food
processing These foams would otherwise cause lems for both the processing operation and final prod-uct quality Typical applications where foaming prob-
prob-lems occur include freeze drying, sugar esses and manufacture of fruit and dietetic soft drinks Similar to antifoaming agents.
proc-Defoliation Removal of leaves from plants Can affect
fruit growth and quality
Deformation Persistent change in shape or size of a
substance in response to an externally applied force Routinely determined for foods during analysis of
rheological properties, and can include puncture
deformation, torsional deformation, breaking tion and maximal (peak) deformation
deforma-Defrosting Thawing of frozen foods, or tively the freeing of an item, e.g freezers, of accumu-
alterna-lated ice
Degassing Alternative term for deaeration.
Degradation A form of decomposition Usually
refers to breakdown of particular compounds in foods
Can have an adverse effect on quality, e.g Modori degradation of proteins in fish surimi, or loss of pigments in fruits during storage However, can
also provide benefits, e.g enzymic degradation of
phytates in plant foods may increase ability of minerals May also reduce the allergenic- ity of allergens, such as gluten.
bioavail-Degreening Process of ripening or improvement of skin or peel colour, usually by application of ethyl- ene to citrus fruits (such as satsuma mandarins and lemons), bananas, rapeseeds and mustard seeds Decay tends to be more severe in degreened
fruit because the degreening process itself promotes decay, and because packaging line fungicide treat-ments have to be delayed until after degreening Un-even degreening of bananas is a ripening disorder characterized by either partial or delayed yellowing or
by permanent greenness after treatment with nous ethylene Green seed is a significant economic
exoge-problem in rapeseeds because the rapeseed oils
ex-tracted from such seed contains chlorophyll-type ments Seed crushers can remove the green colour
Trang 6from rapeseed oil with bleaching clays, but this
in-volves an added expense and poses an environmental
problem
Degumming The first stage in the purification of
crude oils, which involves removal of
phospholip-ids and colouring materials Degumming is necessary
to prevent separation and settling of gums (sticky,
vis-cous oil-water emulsions stabilized by
phospholip-ids) during transportation and storage of crude oils, to
reduce oil losses in the subsequent phases of refining,
and to avoid excessive darkening of the oils in the
course of high-temperature deodorization
Degum-ming agents, such as phosphoric acid, may be used
to-gether with a flocculation agent such as alumina
During water degumming, phosphatides in seed oils
are removed by centrifugal separation, after
precipita-tion with water Acid degumming involves removal of
gums and impurities via centrifugal separation after
precipitation with acid and water By-products of the
degumming process are known as lecithins.
Degumming agents Processing aids used to remove
phospholipids, trace metals and mucilaginous gums
during the initial (degumming) stage of oils and
fats refining Examples include water, phosphoric
acid and citric acid.
Dehairing Removal of the hair from hides and fleece
of animal carcasses, usually by scalding, singeing or
chemical methods Carcasses are dehaired as an
inter-vention to reduce microbial load and improve visual
cleanliness prior to dressing.
Dehulling Removal of the hulls from fruits or
seeds prior to consumption Also called hulling or
husking This term also relates to removal of the
cluster of leaves from the tops of strawberries prior
to consumption
Dehydrated foods Alternative term for dried
foods.
Dehydration Alternative term for drying.
Dehydroacetic acid Organic acid used in
preserva-tives to inhibit microbial growth in foods and
bever-ages.
Dehydroascorbic acid Oxidized form of vitamin
C, which together with ascorbic acid (the reduced
form), makes up the total vitamin C activity in a
sub-stance Present in many food materials, where it has
been implicated in browning or discoloration
reac-tions in certain matrices, such as citrus juices In
breadmaking, dehydroascorbic acid is formed from
ascorbic acid (used in bakery additives) and acts as
an oxidizing agent, promoting formation of disulfide
bonds (important for dough strength)
Dehydrogenases Oxidoreductases that oxidize
substrates by transferring hydrogen atoms to an tor that is either NAD/NADP or a flavin enzyme
accep-Dekkera Genus of yeasts of the family
Saccharomy-cetaceae and class Saccharomycetes Telomorph of
Brettanomyces Important spoilage
microorgan-isms in several foods and beverages Dekkera lensis and D anomala are responsible for the spoilage
bruxel-of beer and wines However, at low levels, these yeasts can have a positive effect on the sensory properties of specific wines and beers Typically iso-
lated from barrel aged wines
Delicatessen foods Speciality ready to eat foods
purchased from delicatessen shops or departments
Ex-amples include delicatessen salads, imported cooked meat products and speciality cheese Also
known as deli foods in the USA
Delicatessen salads Ready to eat chilled salads (frequently mayonnaise-coated) obtained from deli-
catessen shops or departments Examples include
coleslaw, potato salads and herring salads Delphinidin One of the anthocyanidins pigments, often present as a glycoside, and found in many fruits and vegetables Displays antioxidative activity Deltamethrin Non-systemic pyrethroid insecticide
used to control insect pests on a wide range of fruits, vegetables and cereals; also used in stored cereals
and as a dip or spray for cattle, sheep and swine sified by WHO as moderately hazardous (WHO II)
Clas-Demineralization Removal of minerals from
sub-stances Includes processing steps in food manufacture,
such as for sugar syrups, drinking water, musts and whey, and for treatment of food factories ef- fluents Processes used to achieve demineralization include electrodialysis, reverse osmosis and nanofiltration Also covers the undesirable removal
of selected minerals from previously healthy tissues such as bone and tooth enamel, which may be caused
by a variety of factors including nutritional imbalance and excess acidity, respectively
Denaturation Structural change, especially in teins or nucleic acids, in response to extreme con-
pro-ditions of temperature, pH, pressure or salt tion, which renders the molecule incapable of perform-ing its original biological function Used in food proc-
concentra-essing to inactivate detrimental enzymes, or to alter the gelation properties of proteins such as gelatin
or whey proteins However, can also be deleterious, leading to impairment of functional properties such
as water holding capacity in proteinaceous foods,
and to reduced product yields in enzyme catalysis
Denitrification Process of removing nitrogen or nitrogen compounds from a substance, or alterna-
Trang 7tively the liberation of elementary nitrogen from
ni-trogenous compounds in the soil by bacteria.
Densitometry Technique for measuring the optical
density of a material by recording transmission of
light
Density One of the physical properties of a
sub-stance, defined as the mass contained in a given
vol-ume Routinely determined for a wide range of foods,
including fruits and vegetables (sometimes related
to ripeness and composition), fats and oils, foods
produced by extrusion, and cereals Density
deter-minations can also be used as process control steps
in food processing
Dental caries Disease in which cavities are formed in
the teeth resulting ultimately in dental pain and tooth
loss Caries formation is associated with the action of
oral Streptococcus mutans strains Cavity formation
is increased by the consumption of sugar-containing
foods, as the sugar is metabolized by the bacteria to
form acids, which destroy the tooth enamel and
sub-sequently the dentine Increasing oral saliva
produc-tion, achieved by various means such as chewing
chewing gums, can buffer bacterial acid production
and reduce cavity formation Sometimes known as
car-ies
Dental health Measure of the physical condition of an
individual's teeth and gums, or factors influencing their
condition Cariogenic foods, including many with a
high sugar content, promote development of dental
caries (decay), whilst cariostatic or anticariogenic
foods or ingredients reduce these processes
Fluorida-tion of drinking water is undertaken with the aim of
improving dental health, and oligosaccharides with
cariostatic properties are being developed for use as
sweeteners.
species of sea bream.
Deodorization Removal or concealment of an
un-pleasant smell in an item Deodorization is usually the
last step in edible oil refining, involving vacuum-steam
distillation at elevated temperature, during which free
fatty acids and odoriferous volatile compounds
are removed in order to obtain a bland and colourless
product Deodorization can be conducted under
con-tinuous, semi-continuous or batch conditions
Deoxycholate Salt of deoxycholic acid (one of the
secondary bile acids) Used in surfactants and
se-lective media for cell culture, such as
deoxycholate-citrate agar Also known as desoxycholate
Deoxymyoglobin Form of myoglobin in which the
ferric iron in the haem moiety is not bound to O2, but
is commonly bound to water Formed initially on
cut-ting of meat and imparts a purple colour to the meat
Has relatively low oxidative stability and its tion to oxymyoglobin restores a red colour to the
oxida-meat Responsible for the purple colour often seen with
meat subjected to vacuum packaging.
Deoxynivalenol One of the Type B trichothecenes
group of mycotoxins, produced by Fusarium spp Also known as vomitoxin Occurs in Fusarium- infected cereals, primarily those infected with F
graminearum and F culmorum Deoxynivalenol has
been implicated in cases of mycotoxicoses in both mans and animals However, large amounts of grain containing deoynivalenol would have to be consumed
hu-to pose a risk hu-to human health
Deoxyribonucleases Nucleases, also known as
DNases, that cleave the phosphodiester bonds between
nucleotide subunits in single- or double-stranded DNA.
Include endodeoxyribonucleases (EC 3.1.21, 3.1.22 and 3.1.25) which cleave within DNA molecules and
exodeoxyribonucleases which hydrolyse terminal cleotides (EC 3.1.11, 3.1.15 and 3.1.16) Endodeoxy- ribonucleases include the restriction endonucle- ases.
nu-Deoxyribonucleic acid One of the nucleic acids Commonly abbreviated to DNA.
Depolymerization Form of modification in which biopolymers (e.g proteins and polysaccha- rides) are broken down firstly into smaller fractions (peptides and oligosaccharides) and finally into individual monomers (amino acids and sugars) Occurs in pectins and celluloses during ripening.
Depolymerization of polyacrylamides may lead to
formation of acrylamide in foods during heating Depositors Devices for laying down a body of accu-
mulated matter In the food industry, they may be used
to place such substances as fillings, toppings, ters and mixes in position
bat-Depuration To make or become free from impurities using controlled purification systems employing ster-
ilized water Systems can be flow-through or lating types, and water sterilization treatments involve
recircu-the use of chlorine, UV light, ozone, membrane filters
or iodophors Depuration is usually applied to cation of shellfish, such as oysters and mussels.
purifi-Post-harvest depuration in controlled waters can crease the safety of shellfish by reducing the number of
in-pathogens present following harvesting from
moder-ately polluted water
Dermatitis Inflammation of the skin Atopic dermatitis
may be associated with other atopic diseases such as
asthma and type I allergies, including those in
re-sponse to foods
Desalination Removal of salt, e.g desalination of sea water.
Trang 8Desalting Removal of salt.
Desaturases Includes EC 1.3.1.35 and members of
subclass EC 1.14.99 These oxidoreductases have a
number of uses in the food industry, e.g fatty acid
de-saturases introduce double bonds into fatty acyl chains
and are useful for production of polyunsaturated
fatty acids Genetic modification of desaturases in
plants and microorganisms can be used to modify
contents of fatty acids, and cholesterol desaturase
can be used to reduce the cholesterol content of
foods
Desaturation Process by which a substance is made
less saturated In the case of organic compounds,
e.g fatty acids, this involves removal of hydrogen
atoms from adjacent carbon atoms, thereby forming
double bonds and increasing the degree of
unsatura-tion Such reactions are catalysed by desaturases.
In the food industry, introduction of double bonds into
fatty acyl chains in this way is useful for production of
polyunsaturated fatty acids, intake of which can
have beneficial effects for risk of cardiovascular
diseases development
Descaling Removal of deposits of scale from an item,
particularly removal of limescale from heating
ele-ments in kettles and boilers For removal of fish scales,
the alternative term scaling maybe used
Desiccated coconut Product prepared from coconut
endosperm by shredding and drying Used in
manufac-ture of sugar confectionery and bakery
prod-ucts.
Desiccation Alternative term for drying.
Designer foods Functional foods targeted towards
a certain purpose such as the prevention of certain
dis-eases, or provision of tailored health benefits
Desmin One of the animal proteins present in meat
and fish muscle It is an intermediate filament protein
present in the cytoplasm of skeletal, cardiac and
smooth muscle cells In skeletal muscle, it is found
near the Z-line of sarcomeres and is thought to be
in-volved in maintaining alignment of the sarcomeres and
in regulation of the distribution and function of
mito-chondria Post mortem proteolysis of desmin by
calpains has been demonstrated with effects on meat
tenderness and water holding capacity.
Desmosterol Member of the sterols group, found in
a variety of animal and plant foods including goat
milk, sea urchins and wild palm oils It has also
been detected in human milk.
Desmutagenicity Specific type of
antimutagenic-ity relating to the abilantimutagenic-ity of a chemical to counteract
the mutagenicity of another chemical This attribute
has been demonstrated for several foods or isolated
food components, and contributes to their associated
health benefits Foods and components displaying this
property include tea polyphenols, extracts of weeds, cheese and fermented milk Some mi- croorganisms used in food fermentations have also
sea-been shown to have desmutagenic activity, including
Bifidobacterium spp and some lactic acid
bacte-ria.
Desorption Physical or chemical sorption process
by which a substance (gas, liquid or solid) that has been adsorbed or absorbed by a liquid or solid material
is removed from the material Desorption isotherms of
foods during drying are commonly studied to quantify
reductions in moisture content An O2
adsorption-desorption process has been observed in dough ing breadmaking A thermal desorption step is used
dur-in analyte separation durdur-ing GC analyses
Desoxycholate Synonym for deoxycholate Dessert mixes Dried instant foods used to prepare desserts, typically by adding water or milk Also called pudding mixes.
Desserts Sweet foods usually served as the last course
of a meal The term encompasses many different types
of food, including dairy- and fruit-based products, cooked or raw Available frozen, chilled or shelf-
stable, as well as in the form of dessert mixes Popular desserts include cheesecakes, mousses, gateaux, fruit products and ice cream products Dessert wines Sweet wines of varying alcohol con-
tent usually drunk in small amounts as an ment to the dessert course of a meal May also refer to
winemak-high levels of SO2 (1200-2000 mg/l) and then
desul-fited just before fermentation.
Desulfovibrio Genus of sulfate reducing, obligately
anaerobic, rod-shaped Gram negative bacteria of
the family Desulfovibrionaceae Occur in aquatic ronments, including fresh and salt water sediments, and also in the gastrointestinal tracts of animals, and in
envi-faeces Capable of reducing sulfur compounds to drogen sulfide.
hy-Detergents Surfactants, such as soaps, used for cleaning purposes
Deterioration Spoilage process involving a decline
in food quality Can occur during storage via the
ac-tions of microorganisms or chemical reacac-tions Can
Trang 9also be caused by physical processes, such as heating
or freezing.
Detoxicants Substances which inactivate, neutralize,
or render harmless toxins or poisons
Detoxification Process of removing poisons or
tox-ins (e.g from foods), or process of inactivating,
neu-tralizing or rendering harmless toxins or poisons Can
be effected by the use of solvents, chemical reactions,
enzyme systems or microbial action
Detoxification enzymes Enzymes involved in
trans-formation of ingested xenobiotics, including drugs,
pesticides and some food components, to a form that
can be excreted in urine Classified as Phase I and
Phase II enzymes Phase I enzymes initiate
metabo-lism of xenobiotics and include cytochrome P450
monooxygenases, while Phase II enzymes continue
the process by modification of the products of Phase
I enzyme reactions, and comprise many
trans-ferases, including glutathione transferases
He-patic detoxification enzymes have been studied
pre-dominantly The anticarcinogenicity of some plant
foods, e.g garlic, has been linked to their stimulation
of Phase II enzymes
Dewatering Process of removing excess water from a
substance, e.g after washing of a food Used in
proc-essing of foods and in treatment of wastes In the
case of foods, water can be removed by various
proce-dures including passing over vibrating screens, using
specially designed rotary screens or centrifugation.
Dewaxing Process in which solvents are used to
dissolve waxes from oil solutions During the
proce-dure, the wax solution is chilled and removed by
fil-tration.
Dewberries Blackberry-like fruits produced by a
number of Rubus spp., including R caesius in Europe,
and R hispidus or R canadensis in America Similar
in appearance to blackberries, but smaller, with a
slight whitish bloom
Dextran Branched glucans formed by certain lactic
acid bacteria through the fermentation of sugars.
Found in dental plaque and as a deterioration product
in the sugar cane industry Employed widely, such
as in aqueous two phase systems and as a model
polysaccharide molecule in carbohydrate research
Used therapeutically as a substitute for blood plasma
and as a plasma expander under emergency conditions
Dextranases EC 3.2.1.11 Catalyse the
endohydroly-sis of 1,6-Į-D-glucosidic linkages in dextran,
produc-ing isomaltose, isomaltotriose and other
isomal-tooligosaccharides Useful in the sugar industry for
degrading any contaminating dextran that may be
pre-sent, which can interfere with filtration and
clarifica-tion of sugar juices.
Dextransucrases EC 2.4.1.5 ferases which catalyse the synthesis of dextran from sucrose Can also synthesize oligosaccharides,
Glycosyltrans-e.g leucrose (a sugar substitute) in the presence of
ap-propriate sugar acceptors, e.g maltose (a strong ceptor) and fructose (a weak acceptor) Used in the
ac-production of prebiotic oligosaccharides
Dextrinases Previously used as an alternative term for
Į-dextrin endo-1,6-Į-glucosidases, which are now
re-classified as pullulanases (EC 3.2.1.41) Also sionally used in conjunction with limit dextrinases
occa-(EC 3.2.1.142) or with dextrin dextranases occa-(EC 2.4.1.2)
Į-Dextrin endo-1,6-Į-glucosidases Alternative term for pullulanases.
Dextrins General term used for a range of soluble polysaccharides formed by partial hydroly- sis of starch, including maltodextrins and cyclo- dextrins Used for various applications in the food industry, such as prevention of crystallization or as
water-thickeners Their sticky consistency also makes them suitable for use as edible adhesives Cold-water soluble
dextrins are used as carriers for flavourings in ucts such as dry mixes, soups and gravy
prod-Dextrose Name given to the dextrorotary stereoisomer
of glucose (D-glucose)
Dextrose equivalent The percentage of hydrolysis
of glycosidic bonds in products, particularly dextrins, glucose syrups, corn syrups and other starch products, calculated as dextrose (D-glucose)
malto-on a dry weight basis; e.g if 40-60% of the glycosidic bonds are hydrolysed, the corn syrup will have a dex-
trose equivalent of 40-60% Pure glucose has a trose equivalent of 100, pure maltose approximately
dex-50 and starch effectively zero Often abbreviated to DE
DFD defect Abbreviation for dark firm dry defect
of pork.
Dhal Term used in two ways In India, it is used to denote split pulses of a number of varieties, including grass peas and lentils It also refers to a spicy dish
based on lentils or other pulses that may be pureed and served with curries Alternative spellings include dal, dahl and dhall
Dhokla Popular fermented foods of India Typically prepared by soaking meal from chick peas or other legumes in water with buttermilk or curds for sev- eral hours, seasoning with ginger and chillies, and
steaming the batter The steamed cake is cut into
squares, garnished with grated coconut and coriander
and served hot
Diabetes Group of two diseases (diabetes mellitus and
diabetes insipidus) of disparate pathology, both
Trang 10terized by excessive urine production Diabetes
melli-tus, the key feature of which is raised blood sugar
lev-els or impaired glucose tolerance, is classified into two
types: type 1, juvenile-onset or insulin-dependent
dia-betes; and type 2, maturity-onset or non-insulin
de-pendent diabetes Type 1 disease is a result of insulin
deficiency and type 2 disease is due to insulin
resis-tance Control of blood sugar levels can be achieved
by dietary manipulation in some cases, particularly in
mild forms of type 2 disease, by reducing consumption
of foods with high glycaemic index values
Diabe-tes insipidus is due, in general, to reduced ability of the
kidney to concentrate urine, possibly caused by an
im-pairment in the hypothalamus/antidiuretic hormone
system
Diabetic diet A diet designed specifically for
indi-viduals with diabetes to help control their symptoms
and disease progression The amount of sugar or
read-ily available carbohydrate is usually limited to avoid
large increases in blood glucose levels
Diabetic foods Dietetic foods manufactured
spe-cifically for individuals suffering from diabetes.
Generally formulated to be low in absorbable
carbo-hydrates, e.g by replacing sucrose with fructose,
sorbitol or other sweeteners that do not induce a
large increase in blood glucose level
Diacetoxyscirpenol Trichothecene produced by
Fusarium spp Also known as anguidine
Diacetyl Yellow, flammable liquid with a strong
aroma and buttery flavour derived from
fermenta-tion of glucose Soluble in water and alcohol Used
as an aroma carrier in foods and beverages
Diacetyl tartaric acid esters of mono- and
di-glycerides Emulsifiers known by the acronym
DATEM.
Diacylglycerols Glycerides composed of a
mole-cule of glycerol bonded to two fatty acids Possess
emulsifying capacity and are used as additives in
foods, including shortenings Also known as
di-glycerides.
Diafiltration Extension of the ultrafiltration process
in which water is added back to the extract during the
concentration process During diafiltration, both
diffu-sive and convective mass transfer take place
simulta-neously as a result of two driving forces: a
concentra-tion gradient and a transmembrane pressure gradient
This is useful in selectively removing lower molecular
weight materials from a mixture, and offers a useful
alternative process to ion exchange or
electrodi-alysis for removal of anions, cations, sugars,
al-cohol or antinutritional factors Diafiltration is an
accepted method for production of alcohol free, low
calorie and low alcohol beer.
Diallyl disulfide Organic sulfur compound which is a major component of garlic and garlic oils and a ma- jor contributor to their aroma In addition to its sen-
sory properties, the compound also possesses health
benefits including antitumour activity and tion against the risk of cardiovascular diseases Dialysis Separation of particles in a liquid on the basis
protec-of differences in their size and thus ability to pass
through a membrane Membranes are chosen that
will allow small particles to pass through, but retain larger particles The process can be used to remove unwanted particles and enrich or concentrate a solu-tion
Diamine oxidases Alternative term for amine dases.
oxi-Diarrhoea Disorder characterized by loose watery stools which are often evacuated at increased fre-quency Diarrhoea may be an indicator of many dis-
eases of the gastrointestinal tract, including borne diseases, food poisoning, gastroenteri- tis, food intolerance, colitis and colorectal can- cer.
food-Diarrhoetic shellfish poisoning Food poisoning resulting from consumption of marine bivalves con- taining certain diarrhoetic shellfish toxins (such
as okadaic acid) produced by dinoflagellates Symptoms include nausea, intestinal pain, diarrhoea
and memory loss
Diarrhoetic shellfish toxins Toxins produced by certain marine dinoflagellates which are responsible for causing diarrhoetic shellfish poisoning The
most important of these toxins are dinophysistoxin-1,
okadaic acid and derivatives of these compounds Diastases Alternative term for Į-amylases.
Diastatic activity Total activity of starch degrading enzymes in grain malts An important quality charac- teristic for malting and brewing.
Diatomaceous earths Powdery natural materials
formed from the microscopic skeletons of diatoms, posited in most cases during the Cenozoic era Diato-maceous earth is fine in texture and grey or white in colour; when pure, diatomaceous earth is composed almost entirely of silicon dioxide or silica, but it is of-ten found mixed with clay or organic matter The ma-
de-terial is used in fining agents and filtration
materi-als in the food industry, among many other varied and wider fields of application
Diatoxanthin One of the carotenoids detected in several types of fish and shellfish and also in brown seaweeds.
Diazepam Sedative drug that exhibits antihypertensive
and myorelaxant properties Normally used as a feed intake and growth promoting agent Use to reduce
Trang 11stress in animals during transport to
slaughter-houses is not permitted Undergoes extensive and
complex metabolism in animals
Diazinon Non-systemic organophosphorus insecticide
and acaricide used for control of sucking and chewing
insects and mites on a wide range of fruits,
vege-tables, cereals, sugar cane, cocoa, coffee and
tea; also used as a veterinary ectoparasiticide
Classi-fied by WHO as moderately hazardous (WHO II)
Diazocyclopentadiene One of the plant growth
regulators A competitive inhibitor of ethylene that
can be used to control ethylene-induced developmental
responses in fruits and vegetables.
Dicamba Selective systemic herbicide used to control
annual and perennial broad-leaved weeds and brush
species in crops, particularly cereals Often used in
combination with other herbicides Classified by
WHO as slightly hazardous (WHO III) Also known as
banvel
Dichlofluanid Fungicide used for control of scab,
brown rot and other fungal diseases in pome fruits,
stone fruits and various vegetables; also has a
suppressive effect on spider and rust mites on fruits
Classified by WHO as unlikely to present acute hazard
in normal use Also known as euparen
Dichloroacetic acid One of the haloacetic acids
and disinfection by-products found in drinking
water treated with chlorine Chemical formula
C2H2Cl2O2 Also detected in some foods and beverages
washed with chlorinated water Toxicity, including
hepatotoxicity, neurotoxicity and
carcinogenic-ity, has been demonstrated in studies using animal
models.
Dichlorobenzene Organochlorine compound used
widely, including as an insecticide and acaricide in
apiculture, a moth repellent and a deodorant
Classi-fied by WHO as slightly hazardous (WHO III)
2,4-Dichlorophenoxyacetic acid Alternative name
for 2,4-D.
Dichlorprop Selective systemic herbicide used for
post-emergence control of annual and perennial
broad-leaved weeds in cereals Also acts as a plant growth
regulator Classified by WHO as slightly hazardous
(WHO III)
Dichlorvos Organophosphorus insecticide and
acari-cide used for control of insect pests and mites in
stored fruits, vegetables and cereals; also used as
an anthelmintic in animals Classified by WHO as
highly hazardous (WHO Ib) Also known as vapona
Dicing Cutting of materials, such as foods, into small
cubes
Dicloxacillin Semisynthetic penicillin antibiotic used
to treat a range of bacterial infections in animals, ticularly those caused by staphylococci
par-Dicofol Non-systemic organochlorine insecticide and acaricide used for control of mites on a wide range of fruits and vegetables Classified by WHO as
slightly hazardous (WHO III) Also known as kelthane
Dieldrin Persistent organochlorine insecticide that has been used for control of a wide range of insect pests
in crops A breakdown product of aldrin and a potent
neurotoxin Subject to the Stockholm Convention on Persistent Organic Pollutants and usage on crops has
generally been replaced by less persistent cides.
insecti-Dielectric constant One of the electrical ties, describing the ability of a material to store elec-
proper-trostatic energy when a unit voltage is applied Also known as relative permittivity Dielectric constants have been used to determine changes in foods, such as
moisture content changes in sugar confectionery,
or degradation of frying oils, and also to monitor processing steps such as the use of microwaves in thawing and cooking.
Dielectric heating Heating of electrically
non-conducting materials, such as foods, by subjecting
them to high frequency electromagnetic fields The
material to be heated is placed between two electrodes,
to which a source of high-frequency energy is nected In homogeneous materials, the resultant heat-ing occurs throughout
con-Dielectric properties Electrical properties of
dielectric materials, i.e non-conducting materials which can sustain electric fields and act as insulators
These properties include the dielectric constant,
dielectric relaxation and dielectric loss Examples of their use in food analysis include assessment of the
stability of dough during frozen storage, and parison of the quality of musts from different culti- vars of winemaking grapes.
com-Diet Selection by individuals or population groups of
foods and beverages for consumption Dietary sition is the major factor affecting nutrition status and can have profound effects on health and risks for a range of diseases
compo-Dietary fibre Complex mixture of plant cell wall components including lignin and carbohydrates that are resistant to digestion in the small intestine The carbohydrate components include nonstarch polysaccharides Classified into insoluble fibre and soluble fibre High-fibre diets can help control obesity and constipation, reduce the risk of cancer
development and lower blood cholesterol Fibre-rich