1、BRITISH STANDARD BS EN 1133:1995 Method for Determination of formol number of fruit and vegetable juices The European Standard EN1133:1994 has the status of a BritishStandard UDC 663.81/.82:620.1:543.8BSEN1133:1995 This British Standard, having been prepared under the directionof the Consumer Produc
2、ts and Services SectorBoard, was published undertheauthority of the Standards Board and comesintoeffect on 15January1995 BSI12-1999 The following BSI references relate to the work on this standard: Committee reference AW/21 Draft for comment89/54812 DC ISBN 0 580 23153 4 Cooperating organizations Th
3、e European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standard Finland Su
4、omen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unifica
5、zione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Associatio
6、n suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN1133:1995 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Normative references 3 3 Definitions and
7、 symbols 3 4 Principle 3 5 Reagents 3 6 Apparatus 3 7 Procedure 3 8 Calculation 4 9 Precision 4 10 Test report 4 Annex A (informative) Bibliography 5 Annex B (informative) Statistical results of the interlaboratory test 5 National annex NA (informative) Committees responsible Inside back cover Natio
8、nal annex NB (informative) Cross-references Inside back cover Table B1 5BSEN1133:1995 ii BSI 12-1999 National foreword This British Standard has been prepared under the direction of the Consumer Products and Services Sector Board and is the English language version of EN1133 Fruit and vegetable juic
9、es Determination of formol number, published by the European Committee for Standardization (CEN). EN1133 was produced as a result of international discussions in which the United Kingdom took an active part. A British Standard does not purport to include all the necessary provisions of a contract. U
10、sers of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside
11、back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN1133 October 1994 UDC 663.81/.82:620.1:543.8 Descript
12、ors: food products, beverages, fruit and vegetable juices, chemical analysis, determination of content, formol, potentiometricmethods English version Fruit and vegetable juices Determination of the formolnumber Jus de fruits et de lgumes Dterminationdelindice de formol Frucht-und Gemsesfte Bestimmun
13、gderFormolzahl This European Standard was approved by CEN on1994-09-29. 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 bibliograp
14、hical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. The 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
15、 member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain,
16、 Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1994 Copyright reserved to CEN members Ref. No. EN1133:1994EEN1133:1994 BSI 12-1999 2 Foreword Th
17、is European Standard has been prepared by the Technical Committee CEN/TC174, Fruit and vegetable juices Methods of analysis, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a National Standard, either by publication of an identical text or by endorsemen
18、t, at the latest by April1995, and conflicting national standards shall be withdrawn at the latest by April1995. Annexes designated “informative” are given only for information. In this standard Annex A and Annex B are informative. According to the CEN/CENELEC Internal Regulations, the following cou
19、ntries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom.EN1133:1994 BSI 12-1999 3 1 Scope This European Standard specifies a metho
20、d for the determination of the formol number of fruit and vegetable juices and related products. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text an
21、d the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. IS
22、O5725:1986, Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. ISO3696:1987, Water for analytical laboratory use Specification and test methods. 3 Definitions and symbols For the purposes of this standard, the following
23、definition applies: formol number the number of millimoles of sodium hydroxide consumed per litre of test sample according to the method described below. For conformity with existing methods (see Annex A), the formol number is reported as the number of millimetres of sodium hydroxide solution, c (Na
24、OH)=0,1mol/l required per100ml of test sample for the purposes of this standard, the following symbols apply: 4 Principle Upon addition of formaldehyde solution to the test sample, one H + -ion is liberated per molecule of amino acid present. This ion is then treated potentiometrically with sodium h
25、ydroxide solution. The formol number is thus a measure of the amino acid content of the test sample, with the following provisions: the secondary amino group of histidine does not react; those of proline and hydroxyproline react to about75%. Tertiary nitrogen and guanidine groups undergo no reaction
26、. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and only water in accordance with at least grade3 of ISO3696:1987. 5.2 Sodium hydroxide solution, c (NaOH)=0,25mol/l. 5.3 Formaldehyde solution, pH8,1. Formaldehyde solution, 6 (CH 2 O)=at least350g/l, adjusted precisely to pH
27、8,1 on the pH meter with0,25mol/l sodium hydroxide(5.2.). This solution shall be prepared freshly on the day of use. 5.4 Hydrogen peroxide, 6(H 2 O 2 )=300g/l. 6 Apparatus Usual laboratory equipment and, in particular, thefollowing: 6.1 pH meter, accurate to at least0,05pH units. 6.2 pH glass electr
28、ode 6.3 Reference electrode, for example calomel electrode. 6.4 Combination pH glass electrode (alternative to6.2 and6.3). The pH meter and electrode(s) shall be calibrated and serviced according to the manufacturers instructions. 7 Procedure 7.1 Preparation of the test sample Normally products shal
29、l not be pretreated and their analysis by this method shall be on a volumetric basis, results being expressed per100millilitres of sample. The analysis of concentrated products may also be carried out on a volumetric basis, after dilution to a known relative density. In this case, the relative densi
30、ty shall be indicated. Based on a weighed sample and taking the dilution factor for analysis into account, the results may also be expressed per100grams of product. In products with high viscosity and/or very high content of cells (for example pulp), determination on the basis of a weighed test samp
31、le is the usual procedure. In the case of lemon juice or other high acidic juices, take5ml of juice and20ml water and continue as below. If the sample contains sulfur dioxide, it shall be treated with a few drops of hydrogen peroxide solution(5.4) before titration. c Substance concentration; Mass co
32、ncentration.EN1133:1994 4 BSI 12-1999 7.2 Determination While stirring, adjust25ml of test sample in a beaker topH=8,1 using solution(5.2) and the pH meter. Add10ml solution(5.3) and continue stirring. Leave to stand for1minute, then titrate the solution to pH=8,1 using solution(5.2), while continui
33、ng stirring. Note the number of ml (n) of solution(5.2) required for the tiration. If the number of ml required exceeds20ml, repeat the titration using15ml solution(5.3) in place of10ml. Use only sodium hydroxide solution c (NaOH)=0,25mol/l(5.2) for the determination, irrespective of the formol numb
34、er of the test sample. 8 Calculation Calculate the formol number as follows: Formol number=10 n Any additional dilution and the relation of the value to mass or volume(see7.1) shall be taken into account if applicable. If a concentrated product, has been diluted to single strength, report the relati
35、ve density of the single strength sample. The formol number can be calculated per100g of test sample, taking into account the relative density. Report the formol number in millimetres of sodium hydroxide solution c (NaOH)=0,1mol/l per100ml of test sample, to one decimal place. 9 Precision Details of
36、 the interlaboratory test on the precision of the method are summarized in Annex B. The values derived from the interlaboratory test may not be applicable to analyte concentration ranges and matrices other than given in Annex B. 9.1 Repeatability The absolute difference between two single test resul
37、ts found on identical test material by one operator using the same apparatus within the shortest feasible time interval will exceed the repeatability value r in not more than5% of the cases. The value is: r 0,4mmol NaOH/100ml. 9.2 Reproducibility The absolute difference between two single test resul
38、ts on identical test material reported by two laboratories will exceed the reproducibility value R in not more than5% of the cases. The value is: R=1,1mmol NaOH/100ml. 10 Test report The test report shall contain the following data: all information necessary for the identification of the sample (kin
39、d of sample, origin of sample, designation); a reference to this European Standard; date and type of sampling procedure (ifpossible); date of receipt; date of test; test results and units in which they have been expressed; whether the repeatability has been verified; any particular points observed i
40、n the course of the test; any operations not specified in the method or regarded as optional, which might have affected the results.EN1133:1994 BSI 12-1999 5 Annex A(informative) Bibliography 1 Determination of the Formol Number:No30,1984 In: Analyses Collection/International Federation of Fruit Jui
41、ce Producers Loose-leaf edition, as of1989, Zug: Swiss Fruit Union. 2 Untersuchung von Lebensmitteln: Bestimmung des Formolwertes von Fruchtsften: L31.00-8,1983-11 Food Analysis: Determination of the formol number of fruit juices: L31.00-8,1983-11 In: Amtliche Sammlung von Untersuchungsverfahren nac
42、h35LMBG: Verfahren zur Probenhame und Untersuchung von Lebensmitteln, Tabakerzeugnissen, kosmetischen Mitteln und Bedarfsgegenstnden/Bundesgesundheitsamt In: Collection of official methods under article35 of the German Federal Foods Act: Methods of sampling and analysis of foods, tobacco products, c
43、osmetics and commodity goods/Federal Health Office Loseblattausgabe, Stand31.12.1991, Bd.l. Loose-leaf edition, as of1991-12-31, Vol.1. Berlin, Kln: Beuth Verlag GmbH. Annex B(informative) Statistical results of the interlaboratory test In accordance with ISO5725:1986, the following parameters have
44、been defined in an interlaboratory test. (For literature pertaining to the method see Annex A). The test was conducted by the Max von Pettenkofer Institute of the Federal Health Office, Food Chemistry Department, Berlin, BRD: Table B1 Sample types: A cherry nectar B grape juice, white C orange juice
45、 Year of interlaboratory test 1982 number of laboratories 25to28 number of samples 3 Sample A B C Number of laboratories retained after eliminating outliers Number of outliers (Laboratories) Number of accepted results 23 2 114 25 2 123 23 5 117 Mean value () (mmol NaOH/100ml) 13,4 14,8 22,5 Repeatab
46、ility standard deviation (s r ) (mmol NaOH/100ml) Repeatability relative standard deviation (RSD r ) % 0,1276 0,95 0,1240 0,84 0,1352 0,60 Repeatability limit (r)(mmol NaOH/100ml) 0,4 0,4 0,4 Reproducibility standard deviation (s R ) (mmol NaOH/100ml) Reproducibility relative standard deviation (RSD
47、 R ) % 0,4147 3,09 0,3555 2,40 0,4283 1,90 Reproducibility limit (R)(mmol NaOH/100ml) 1,2 1 1,2 x6 blankBSEN1133:1995 BSI 12-1999 National annex NA(informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Consumer Products
48、 and Services Sector Board to Technical Committee AW/21 upon which the following bodies were represented: British Food Manufacturing Industries Research Association British Fruit Juice Importers Association British Retail Consortium British Soft Drinks Association Limited Campden Food and Drink Rese
49、arch Association Department of Trade and Industry (Laboratory of the Government Chemist) Ministry of Agriculture, Fisheries and Food Royal Society of Chemistry National annex NB(informative) Cross-references International Standard Corresponding British Standard ISO3696:1987 BS3978:1987 Specification for water for laboratory use ISO5725:1986 BS5497 Precision of test methods Part1:1987 Guide for the determination of repeatability and reproducibility for a standard test method by inter-laborato
