Tiêu chuẩn iso 06887 2 2017

© ISO 2017 Microbiology of the food chain — Preparation of test samples, initial suspension and decimal dilutions for microbiological examination — Part 2 Specific rules for the preparation of meat an[.]

Microbiolog y ofthe food chain —

Part 2:

Specific rules for the preparation of

Micro iolo ie de la ch îne alimentaire — Pré aration de s

éch ntillo s,de la sus pension mè e et de s d utions décimale s en v e

de l’e xamen micro iolo ique —

Partie 2: Règle s spécifique s p ur la pré aration de s viande s  et 

produits carn s

S con edition

2 17-0

Refer ence n mb r

ISO 68 7-2:2 17(E)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2017, P blshed in Sw itz rlan

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written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

the r eq eser

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CH-1 14 Vernier, Geneva, Switzerlan

Tel + 12 7 9 011

Fax 412 7 9 0 4

F reword i v

1 Sc ope 1

2 Nor mati ve r eferenc es 2

3 Terms and definitions 2

4 Principle 2

5 Diuents 3

6 A pparatus 3

7 S mpl n and sample types 3

7.1 General

3 7.2 General types of samples sent to the la or atory 3

7.3 Spe ific types of samples sent o the la oratory 3

8 Preparatio of samples 4

8.1 General 4

8.2 Purp se of testing 4

8.3 General case for acidic pr od cts 4

8.4 High-fat pr oduct (o e 2 % of total mas as fat) 4

9 Specific pr oc edures 4

9.1 Initial pr ep ration of the diferent types of samples 4

9.1.1 L b ratory sample with a mas eq al to or les than 5 g 4

9.1.2 Blocks, lar g e pie es, meat cuts 4

9.1.3 Slc sor pie es of meat or co ked meat 5

9.1.4 Frag ments, sha ving s an trimming s 5

9.1.5 Meat prod ct in “ skins” ( ausag es) 5

9.1.6 C oked meat 5

9.1.7 Chicken and duck fe t 5

9.2 Pr oc dure for pre-p cked pr oducts 5

9.3 Pr oc dure for non-fr oz n pr od ct 5

9.3.1 Sample pr ep ration from depth within the tes mate ial 5

9.3.2 Sample pr ep ration from the surfac of meat (excision/des ructive method) 5

9.3.3 Sample pr ep ration from in ividual slc s 6

9.3.4 Sample pr ep ration of car cas samples 6

9.4 Sample pr eparation for fr oz n prod ct 6

9.5 Sample pr eparation for dried an p rtialy dehydrated meat an meat extract 6

9.6 Sample pr eparation of surfac samples ( wa san othe devic s) 6

10 F rther di utio s 6

A nne x A (informative)Template for the delne tio of a sur face sample area 7

Biblog raphy 9

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www iso org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www iso org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

For an ex lanation on the meaning of ISO spe ific terms an ex r s ions r lat ed to conformity as es ment,

as wel as information a out ISO’s adhe enc to the Wor ld Trade Org nization (WTO) principles in the

Te h ical Bar ie s to Trade (TBT) se the folowing URL: www iso org iso/ for word html

The committ ee r sp nsible for this document is ISO/TC 34, Fo d produc ts , Subcommitt ee SC 9,

Mic ro iolo y

This se on edition canc ls an r plac sthe firs edition (ISO 6 8 - 2:2 0 ), w hich has be n t ech icaly

r vised

A l s of p rt in the ISO 6 8 se iescan be foun on the ISO websit e

Microbiolog y ofthe food chain — Pr eparation oftest

Part 2:

WARNING — The use of this document may inv lve hazardous materials, o eratio s and

equipment It is the respo sibiity of the use of this document to establ sh ap ro riate safety

and he lth practices an to determine the ap l cabi ity of re ulatory l mitatio s before use

This document spe ifies rules for the pr paration of meat an meat prod ct samples an their

suspension for mic o iolo ical ex mination w hen the samples r q ir dife ent pr p ration from the

methods desc ibed in ISO 6 87-1 ISO 68 7-1 defines the g ene al rules for the pr p ration of the initial

suspension an diutionsfor mic o iolo ical ex mination

This document ex clu es pr p ration of samples for both en me ation an det ection t es methods

w he e pr p ration detai s ar spe ified in the r lev nt Int ernational Stan ards

This document is a plca le t o the folowing fr sh, raw an proc s ed meat , p ultry and g me an

their prod ct :

— r frig erat ed or froz n;

— cur d or fe ment ed;

— minc d or commin t ed;

— meat pr p rations;

— me hanicaly sep rat ed meat ;

— co ked meat ;

— dried an smoked meat at v rious degr esof dehydration;

— conc ntrat ed meat extract ;

— ex cision an swa samples from car as es

This document ex clu es the sampl ng of car as es ( e ISO 17 604 ) an pr p ration of samplesfrom the

primary prod ction s ag e ( e ISO 6 8 -6)

2 Normati ve referenc es

The folowing document ar r fe r d t o in the t ext in such a wa that some or al of their cont ent

cons itut es r q ir ment of this document F or dat ed r fe enc s, only the edition cit ed a ples F or

un at ed r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amendment ) a ples

ISO 68 7-1, Mic ro iolo y o the fod chain — Prep ration o tes t s amples , initial s us pens io a d dec imal

diutio s fr mic ro iolo ic al ex min tio — Part 1: G ene al rules fr the pr p ratio o the initial

s us pens io a d dec imal diutio s

ISO 7 1 , Mic ro iolo y o f od a d a imal fe din s tufs — G ene al r q ir ments a d g ida ce fr

mic ro iolo ic al ex min tio s

ISO 17604, Mic ro iolo y o the fod chain — Carc as s s ampln fr mic ro iolo ic al a alys i s

ISO 1 5 3, Mic ro iolo y o fod a d a imal fe din s tu fs — Hori zo tal meth ds fr s ampln te h iq es

from s urfc es us in c ontac t plates a d swa s

3 Terms and definitions

F or the purp ses of this document, thet ermsan definitions given in ISO 6 87-1 an thefolowing a ply

ISO an IEC maintain t erminolo ical data ases for use in s an ardization at the folowing ad r s es:

— IECEle tro edia: a aia le at ht p:/ www ele tro edia org

— ISO Onlnebrow sing plat orm:a ai a le at ht p:/ www iso org o p

3.1

block

larg e piece

me t cut

sample w hose composition an dimensions ( urfac an thick es , but thick es in p rticular) alow a

sample t o be taken at depth u de satis act ory st erie con itions

3.2

shaving

sample from froz n meat r sulting from a cut surfac sample

3.3

fra ment

sample taken at depth inside the t es pie e b ele tric dri l or a hand-dri

3.4

slce

cut of meat with a pro imat ely paralel sides up t o seve al c ntimetr s thick

3.5

trimming

meat sc a that has be n cut from car as es or larg er pie es of meat

4 Principle

The g ene al principles for sample pr paration an subseq ent st eps ar detaied in ISO 6 8 -1 w hie

ISO 68 7- 2 desc ibes spe if ic sample pr p ration for meat an meat prod ct

5 Di uents

Diuent for g ene al use an spe ial purp ses ar desc ibed in ISO 6 8 -1 an the e ar no ad itional

spe if ic r q ir ment for meat an meat prod ct

6 A pparatus

Usual mic o iolo ical la orat ory eq ipment for g ene al use (ISO 6 8 -1 an ISO 7 1 ) an , in

p rticular, the folowing

6.1 E uipment for cauterizatio of me t surfaces, e.g p rta le g as blowtor ch

6.2 Template for surfac e samplng , metal c or plas ic frame of a pr opriate dimensions ena lng

the delneation of the surfac to be sampled, s e i z d b autocla ving or imme sion in 7 % (v lume

fr action)alcohol an flaming

An ex mple of a t emplat e or frame is shown in An ex A, but othe suita le t ools ar a ai a le As

some spor s might survive flaming, a pr -st eri iz d metal t emplat e is r commen ed w hen t es ing for

sp rulat ed mic o rg nisms

7 Sampl ng and sample types

Car y out samplng in ac ordanc with the spe ific s an ard a pro riat e t o the prod ct conc rned or

se ISO/TS 1 7 8 If a spe if ic s an ard is not a ai a le, it is r commen ed that a r ement be r ached

on this subje t b the p rties conc rned

7.2 General types of samples sent to the laboratory

Methods for han l ng the g ene al ty es of samples that ma be submitt ed for t es ing, such as froz n,

hard an dry, lq id an non-viscousprod ct , an multi-component prod ct ar detaied in ISO 68 7-1

as these ar a plca le t o many ty es of fo d an fe d

7.3 Specific types of samples sent to the laborator y

Meat an meat-b sed prod ct ma inclu e any ofthe folowing ty es:

— unit of meat or meat-b sed prod ct , pr p r d or proc s ed an of dife ent dimensions;

— cut of meat taken from larg er u it of meat ;

— primal cut of meat aken from car as es;

— sha ings or fra ment taken from froz n blocks;

— ofal from v rious spe ies;

— oriental delcacies such as chicken an d ck fe t

Tis ues, swa s or othe ty es of samples cole t ed using non-des ructive methods ( e ISO 17604 ) ma

also be sent t o the la orat ory

The phy sical s at e of the samplesr c ived ma v ry ac ording t o the folowing fact ors:

a) t empe atur , for prod ct that ar

— non-froz n, or

— froz n or de p-froz n ( e ISO 7 1 );

b) wat er activity (a

w ), for prod ct that ar

— untr at ed, or

— int ermediat e mois ur meat prod ct in w hich mic o ial growth is inhibit ed as a r sult of the

r d c d wat er activity (a

w )

8 Preparation ofsamples

Al pr parations an manipulationsshal be car ied out using aseptic t ech iq es with st erie eq ipment

(ISO 7 1 )

8.2 Purpose of testing

Gene al detaisar given in ISO 7 1

The purp se of mic o iolo ical t es ing of meat inclu es det ection an / r en me ation of

— mic o ial flora from samples taken at depth,

— surfac mic o ial flora, or

— mic o ial flora from the entir sample ( urfac an depth)

Pr p ration of samples shal take int o ac ount he aim of the t es ing an the natur of the sample

8.3 General case for acidic pr oducts

The g ene al case for pr p ration of acidic prod ct (pH betwe n 3,5 an 4,5) is given in ISO 6 8 -1 an

the e ar no ad itional spe ific r q ir ment for meat an meat prod ct

8.4 High-fat products (over 20 % of total mas as fat)

The g ene al case for pr paration of high-fat prod ct is given in ISO 6 8 -1 an the ear no ad itional

spe ific r q ir ment for meat an meat prod ct

9 Specific pr ocedures

9.1 Initial pr eparation of the diferent types of samples

This a ples only t o samples for the det ection or en me ation of the t otal mic o ial flora from b th

the surfac an depth Use suff icient mat erial from the la orat ory sample t o give a r pr sentative t es

p rtion as spe ified in the t es method

9.1.1 Lab ratory sample with a mas equal to or les than 50 g

Use the w hole la orat ory sample for pr p ration of the initial suspension if the samplemas is eq al t o

or les than 5 g

9.1.2 Blocks, lar g e piec es, me t cuts

F or meat cut , take the t es p rtion at depth an / r a surfac sample an pr p r the initial suspension

9.1.3 Slc es or piec es of me t or c ooked me t

Take s rips from the c ntr of the slc s or pie es t o pr par the initial suspension

9.1.4 F rag ments, shaving s and trimming s

Homog eniz these thoroughly befor r mo ing the t es portion for pr p ration of the initial suspension

9.1.5 Me t prod cts in “skins” (sausag es)

If the skin is not int en ed for consumption, disinfe t the co ked or raw sausag es at the p int of incision

b wiping the surfac with 7 % (v lume fraction) alcohol or b caut erizing using a blowt or h (6.1);

pul t o r move the skin with st erie for eps or t ongs Slc the sausag es an cut int o smal pie es befor

homog enizing

Do not r move edible skins from raw sausag es, but slc an homog eniz inclu ing the skin

9.1.6 C oked me ts

F or p ckag ed co ked meat , o en the p cka ing in ac ordanc with 9.2 and pr p r t es p rtions as for

raw prod ct

9.1.7 C icken and duck fe t

Cut seve al u it of chicken or d ck fe t ( inclu ing al p rt ) with a p ir of st erie scis ors along

the joint int o smale pie es Mix an weigh out the t es p rtion in a tar d st erie plas ic b g Ad

nine times this mas of an a pro riat e di uent ISO 68 7-1) an mas ag e b han for 1 min t o 2 min t o

make the 1 in 1 initial suspension

9.2 Proc edure for pre-packed products

F or g ene al ins ructions on sample pr p ration of p ckag ed prod ct , se ISO 6 87-1

9.3 Proc edure for non-frozen pr oducts

9.3.1 S mple preparatio fr om depth within the test material

Such t es portions ar used t o ex mine only the de p tis ue an sampl ng is car ied out aft er

caut erization of the surfac Use scalpels an for eps t o r mo e an a pro riat e ar a of skin from cut of

meat pr sent ed with skin on

If p ckag ed, r mo e the sample aseptical y and plac on a st erie tra R emo e a surfac la e 2 mm

t o 5 mm thick from the up e surfac t o ex ose an ar a of a pro imat ely 5 cm b 5 cm with a st eri e

scalpel or k ife Caut eriz this ex osed surfac using a blowt or h (6.1) u ti char ing oc urs Using a

fr sh st eri e knife or scalpel, r mo e a la e a out 4 cm b 4 cm an 1 cm de p from below the char ed

ar a Using st erie for eps an scalpel, r mo e the r q ir d t es p rtion from the ex osed ar a an

plac it in a tar d st erie containe or plas ic b g

Weigh the t es p rtion an ad nine timesthismas of an a pro riat e diuent ISO 68 7-1) t o make the

1 in 1 initial suspension

9.3.2 S mple preparatio fr om the surfac e of me t (e xcision/destructi ve meth d)

Samples ar taken without caut erization of the ex osed surfac

If packag ed, it ma be ne es ary t o r mo e the meat asepticaly an plac it on a st erie tra with the

t es surfac up e mos Use a st eri z d or disinfe t ed t emplat e (6.2) an a ply t o the designat ed ar a

( e Annex A)

Using a st eri e scalpel, cut along the inside edg es of the t emplat e Then, using st erie for eps t o l f the

t es p rtion, cut ac os the w hole ar a t o a depth of 2 mm t o 3 mm an plac the pie es in a tar d st erie

containe or plas ic b g

Weigh the t es p rtion an ad nine timesthismas of an a pro riat e diuent (ISO 6 8 -1) t o make the

1 in 1 initial suspension

F or such surfac samples, the initial diution should be r corded F or ex mple, from a sample from a

2

surfac diut ed in a t otal v lume of 1 0 ml ofdiuent, 1 ml of this initial suspension r pr sent

0,2 cm

2

9.3.3 S mple preparatio from indi vidual slc es

Samples ar taken without caut erization of the ex osed surfac

If packag ed, it ma be ne es ary t o r mo e the meat asepticaly and plac it on a st erie tra with the

t es surfac up e mos

Using a st eri e scalpel an for eps, cut a s rip 1 cm wide along the c ntr of the gr at es length Cut the

s rip int o smal pie es an plac them int o a tar d st erie containe or plas ic b g

Weigh the t es p rtion an ad nine timesthismas of an a pro riat e diuent (ISO 6 8 -1) t o make the

1 in 1 initial suspension

9.3.4 S mple preparatio of car cas samples

Proc d r s for sampl ng car as es from fr shly slaught er d animals ar given in ISO 17604

9.4 S mple preparation for frozen products

Proc d r s for han lng smal samples of al ty es b defros ing befor samplng an those for samplng

larg er blocks of meat an meat prod ct without pr lminary defros ing ar given in ISO 6 87-1

9.5 S mple preparation for dr ied and partial y dehydrated meats and meat ex tracts

Proc d r s for dried an p rtial y dehydrat ed prod ct ar given in ISO 6 8 -4

9.6 S mple preparation ofsurface samples (swabs and other devic es)

F or non-des ructive car as samplng using swa s or othe devic s, r fe t o ISO 17 604

F or g ene al pr p ration an calculation ins ructions for swa s an othe devic s, r fe t o ISO 1 5 3

10 Further di utions

Pr p r furthe di utions in ac ordanc with ISO 6 87-1