DIN EN ISO 4833-2-2014 Microbiology of the food chain - Horizontal method for the enumeration of microorganisms - Part 2 Colony count at 30 degrees C by the surface plating techniq.pdf

1、May 2014 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 07

2、.100.30; 65.120!%2English version EN ISO 4833-2:2013 + AC:2014,English translation of DIN EN ISO 4833-2:2014-05Mikrobiologie der Lebensmittelkette Horizontales Verfahren fr die Zhlung von Mikroorganismen Teil 2: Koloniezhlung bei 30 C mittels Oberflchenverfahren (ISO 4833-2:2013 +Cor. 1:2014);Englis

3、che Fassung EN ISO 4833-2:2013 + AC:2014,Englische bersetzung von DIN EN ISO 4833-2:2014-05Microbiologie de la chane alimentaire Mthode horizontale pour le dnombrement des micro-organismes Partie 2: Comptage des colonies 30 degrs C par la technique densemencement ensurface (ISO 4833-2:2013 + Cor. 1:

4、2014);Version anglaise EN ISO 4833-2:2013 + AC:2014,Traduction anglaise de DIN EN ISO 4833-2:2014-05SupersedesDIN EN ISO 4833-2:2013-12www.beuth.deDocument comprises 19 pagesIn case of doubt, the German-language original shall be considered authoritative.04.14 DIN EN ISO 4833-2:2014-05 2 A comma is

5、used as the decimal marker. National foreword This document (EN ISO 4833-2:2013) has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France/ABNT, Brazil), Subcommittee SC 9 “Microbiology” (Secretariat: AFNOR, France) in collaboration with Technical Committee CEN/T

6、C 275 “Food analysis Horizontal methods” (Secretariat: DIN, Germany). Based on the results of parallel voting, ISO 4833-2:2013 has been adopted as a European Standard. The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food

7、and Agricultural Products Standards Committee), Working Committee NA 057-01-06 AA Mikrobiologische Lebensmitteluntersuchung einschlielich Schnellverfahren. ISO/TC 34/SC 9 decided to revise and subdivide EN ISO 4833 into two parts. EN ISO 4833 Part 1 specifies a horizontal method for the enumeration

8、of microorganisms at 30 C by the pour plate technique and supersedes EN ISO 4833:2003. EN ISO 4833 Part 2 specifies a horizontal method for the enumeration of microorganisms at 30 C by the surface plating technique. DIN EN ISO 4833 consists of the following parts, under the general title Microbiolog

9、y of the food chain Horizontal method for the enumeration of microorganisms: Part 1: Colony count at 30 C by the pour plate technique Part 2: Colony count at 30 C by the surface plating technique The DIN Standards corresponding to the International Standards referred to in this document are as follo

10、ws: ISO 6887 (all parts) DIN EN ISO 6887 (all parts) ISO 7218 DIN EN ISO 7218 ISO 11133 DIN EN ISO 11133 Amendments This standard differs from DIN EN ISO 4833:2003-06 as follows: a) Clause 1 “Scope” has been rendered more precise and specifies in detail the application of the surface plating techniq

11、ue; b) colony count at 30 C by the surface plating technique has been added as a new technique. Compared with DIN EN ISO 4833-2:2013-12, the following correction has been made: a) in Subclause 5.3.1, first line, “Enzymatic digest of animal tissues” has been replaced by “Enzymatic digestion of casein

12、”. Previous editions DIN10192-1: 1981-01, 1984-04 DIN EN ISO 4833: 2003-06, 2013-12 DIN EN ISO 4833-2: 2013-12 DIN EN ISO 4833-2:2014-05 3 National Annex NA (informative) Bibliography DIN EN ISO 6887 (all parts), Microbiology of food and animal feeding stuffs Preparation of the test samples, of init

13、ial suspension and of decimal dilutions for microbiological examination DIN EN ISO 7218, Microbiology of food and animal feeding stuffs General requirements and guidance for microbiological examinations DIN EN ISO 11133, Microbiology of food, animal feed and water Preparation, production, storage an

14、d performance testing of culture media DIN EN ISO 4833-2:2014-05 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4833-2 September 2013 + AC February 2014 ICS 07.100.30 Supersedes EN ISO 4833:2003 English Version Microbiology of the food chain Horizontal me

15、thod for the enumeration of microorganisms Part 2: Colony count at 30 degrees C by the surface plating technique (ISO 4833-2:2013 + Cor. 1:2014) Microbiologie de la chane alimentaire Mthode horizontale pour le dnombrement des micro-organismes Partie 2: Comptage des colonies 30 degrs C par la techniq

16、ue densemencement en surface (ISO 4833-2:2013 + Cor. 1:2014) Mikrobiologie der Lebensmittelkette Horizontales Verfahren fr die Zhlung von Mikroorganismen Teil 2: Koloniezhlung bei 30 C mittels Oberflchenverfahren (ISO 4833-2:2013 + Cor. 1:2014) EN ISO 4833-2:2013 was approved by CEN on 2013-07-26 an

17、d Corrigendum AC:2014 on 2014-02-19. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such na

18、tional standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own lan

19、guage and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greec

20、e, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG M

21、anagement Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4833-2:2013 + AC:2014 E Contents PageForeword to EN ISO 4833:2013.31 Scope . 42 Normative references 43 Terms and definiti

22、ons . 54 Principle 55 Culture media and diluents . 55.1 General . 55.2 Diluents . 55.3 Agar medium: plate count agar (PCA) 56 Apparatus . 67 Sampling 78 Preparation of test sample . 79 Procedure. 79.1 Test portion, initial suspension and dilutions 79.2 Inoculation and incubation 79.3 Counting of col

23、onies . 810 Expression of results 811 Test report . 8Annex A (normative) Surface colony count using a spiral plater 9Bibliography .15DIN EN ISO 4833-2:2014-05 EN ISO 4833-2:2013 + AC:2014 (E) 2Foreword to EN ISO 4833:2013 + AC:2014 .3DIN EN ISO 4833-2:2014-05 EN ISO 4833-2:2013 + AC:2014 (E) 3Forewo

24、rd to EN ISO 4833-2:2013 This document (EN ISO 4833-2:2013) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 275 “Food analysis Horizontal methods” the secretariat of which is held by DIN. This European Standard shall be given the st

25、atus of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2014, and conflicting national standards shall be withdrawn at the latest by March 2014. Attention is drawn to the possibility that some of the elements of this document may be the subje

26、ct of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 4833:2003, together with EN ISO 4833-1:2013. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following c

27、ountries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

28、 Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 4833-2:2013 has been approved by CEN as EN ISO 4833-2:2013 without any modification. Foreword to EN ISO 4833-2:2013/ / AC:2014 This document (EN ISO 4833-2:20

29、13/AC:2014) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 275 “Food analysis Horizontal methods” the secretariat of which is held by DIN. Endorsement notice The text of ISO 4833-2:2013/Cor. 1:2014 has been approved by CEN as EN IS

30、O 4833-2:2013/AC:2014 without any modification. 1 ScopeThis part of ISO 4833 specifies a horizontal method for enumeration of microorganisms that are able to grow and form colonies on the surface of a solid medium after aerobic incubation at 30 C. The method is applicable to:a) products intended for

31、 human consumption or for animal feed;b) environmental samples in the area of food and feed production and food handling.This part of ISO 4833 is applicable to:1) products containing heat-sensitive organisms that are likely to form a significant proportion of the total flora (e.g. psychrotrophic org

32、anisms in chilled and frozen foods, dried foods, other foods that may contain heat-sensitive organisms);2) products containing obligately aerobic bacteria that are likely to form a significant proportion of the total flora (e.g. Pseudomonas spp.);3) products that contain small particles that can pro

33、ve difficult to distinguish from colonies in a pour plate;4) products whose intense colour prevents the recognition of colonies in a pour plate;5) products for which distinction between different types of colony is required as part of the assessment of food quality.In addition to the manual spread p

34、lating technique, this part of ISO 4833 also specifies the use of a spiral plater, a rapid method of performing surface colony counts (Annex A).The applicability of this part of ISO 4833 to the examination of certain fermented food and animal feeds is limited and other media or incubation conditions

35、 can be more appropriate. However, this method can be applied to such products even though it is possible that the predominant microorganisms in these products are not detected effectively.For some matrices, the method described in this part of ISO 4833 can give different results to those obtained u

36、sing the method described in ISO 4833-1.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the r

37、eferenced document (including any amendments) applies.ISO 6887 (all parts), Microbiology of food and animal feeding stuffs Preparation of test samples, initial suspension and decimal dilutions for microbiological examinationISO 7218, Microbiology of food and animal feeding stuffs General requirement

38、s and guidance for microbiological examinationsDIN EN ISO 4833-2:2014-05 EN ISO 4833-2:2013 + AC:2014 (E) 4 ISO 11133, Microbiology of food, animal feed and water Preparation, production, storage and performance testing of culture media3 Terms and definitionsFor the purposes of this document, the fo

39、llowing terms and definitions apply.3.1microorganismentity of microscopic size, encompassing bacteria, fungi, protozoa and virusesSOURCE: ISO/TS 11139:2006,32.26Note 1 to entry: For the purposes of this part of ISO 4833, microorganisms are bacteria, yeasts and moulds that are able to produce colonie

40、s under the conditions specified in this part of ISO 4833.4 PrincipleA specified quantity of the test sample, or a specified quantity of an initial suspension in the case of other products, is surface plated on a solid agar culture medium contained in Petri dishes.Other plates are prepared under the

41、 same conditions using decimal dilutions of the test sample or of the initial suspension.The plates are incubated under aerobic conditions at 30 C for 72 h.The number of microorganisms per gram of sample or the number of microorganisms per millilitre of sample is calculated from the number of coloni

42、es obtained on the plates containing fewer than 300 colonies.5 Culture media and diluents5.1 GeneralFollow ISO 11133 for the preparation, production and performance testing of culture media.5.2 DiluentsUse the diluent(s) specified in ISO 6887 for the product concerned or the specific International S

43、tandard dealing with the product under examination.5.3 Agar medium: plate count agar (PCA)5.3.1 CompositionEnzymatic digestion of casein 5,0 gYeast extract 2,5 gGlucose, anhydrous (C6H12O6) 1,0 gAgara9 g to 18 gWater 1 000 mlaDepending on the gel strength of the agar.When dairy products are examined

44、, add skimmed milk powder at 1,0 g/l of the culture medium. The skimmed milk powder shall be free from inhibitory substances.DIN EN ISO 4833-2:2014-05 EN ISO 4833-2:2013 + AC:2014 (E) 5 5.3.2 PreparationDissolve the components or the dehydrated complete medium in the water, by heating if necessary.

45、Mix thoroughly and leave to stand for several minutes.Adjust the pH (6.5), if necessary, so that after sterilization it is 7,0 0,2 at 25 C.Dispense the medium into flasks or bottles (6.9) of suitable capacity. Sterilize in an autoclave (6.1) at 121 C for 15 min.If the medium is to be used immediatel

46、y, cool it in a water bath (6.4) maintained at 47 C to 50 C before use. If not, allow the medium to solidify in the flask or bottle. Before use, melt the medium completely in a boiling water bath, then cool it in the water bath (6.4) maintained at 47 C to 50 C.5.3.3 Preparation of agar platesPour 15

47、 ml to 20 ml of the medium into sterile Petri dishes (6.6) and allow to solidify.The plates may be stored at (5 3) C for up to 4 weeks.Immediately before use, the agar plates should be dried in accordance with ISO 11133.5.3.4 Performance testing of the culture medium5.3.4.1 GeneralPlate count agar i

48、s a non-selective medium, used in this part of ISO 4833 as a pre-poured plate for surface inoculation. Productivity shall be tested according to ISO 11133.5.3.4.2 ProductivityIncubation (30 1) C for (72 3) h Control strains Escherichia coli WDCM 00013 or WDCM 00012aWorld Data Centre for Microor-ganism