1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12134 : 1998 The Eu
2、ropean Standard EN 12134 : 1997 has the status of a British Standard ICS 67.160.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Fruit and vegetable juices Determination of centrifugable pulp contentThis British Standard, having been prepared under the direction of the Consu
3、mer Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect on 15 February 1998 BSI 1998 ISBN 0 580 28966 4 BS EN 12134 : 1998 Amendments issued since publication Amd. No. Date Text affected National foreword This British Standard is the Eng
4、lish language version of EN 12134. The UK participation in its preparation was entrusted to Technical Committee AW/21, Fruit and vegetable juices, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation,
5、 or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which impleme
6、nt international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does
7、 not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 4, an inside back cover and a back cover.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komi
8、tee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12134 : 1997 E EUROPEAN STANDARD EN 12134 NORME EUROPE ENNE EUROPA ISCHE NORM September 1997 ICS 67.160.
9、20 Descriptors: Fruit and vegetables juices, tests, determination of content, pulps, centrifugal analysis, procedure English version Fruit and vegetable juices Determination of centrifugable pulp content Jus de fruits et de le gumes De termination de la teneur en pulpe centrifugeable Frucht- und Gem
10、u sesa fte Bestimmung des Gehaltes an zentrifugierbarer Pulpe This European Standard was approved by CEN on 6 September 1997. 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 w
11、ithout any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other languag
12、e made by translation under the responsibility of a CEN 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, Czech Republic, Denmark, Finland, France, Germany, Greece, Ice
13、land, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 12134 : 1997 BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 174, Fruit and vegetable juices Methods of analysis, the Secretariat of which
14、 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 endorsement, at the latest by March 1998, and conflicting national standards shall be withdrawn at the latest by March 1998. According to the CEN/CENELEC Inter
15、nal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland
16、and the United Kingdom. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Symbol 3 4 Principle 3 5 Apparatus 3 6 Procedure 3 7 Calculation 3 8 Precision 4 9 Test report 4 Annexes A (informative) Bibliography 4 B (informative) Statistical results of the inter-laboratory test 4Page 3 EN 12
17、134 : 1997 BSI 1998 1) Heraeus type 3113 is an example of a suitable product available commercially. This information is given for the convenience of users of this standard and does not constitute an endorsement by CEN of this product. 1 Scope This European Standard specifies a centrifugation method
18、 for the determination of the pulp content of fruit and vegetable juices and related products. 2 Normative references This European Standard incorporates by dated or undated references, provisions from other publications. These normative references are cited at the appropriate places in the text and
19、 the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. IS
20、O 5725 : 1986 Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests 3 Symbol For the purposes of this European Standard, the following symbol applies: g acceleration due to gravity at the surface of the earth (9,81 m/s 2 ).
21、4 Principle The sample is centrifuged and the content of pulp is determined as a percentage by volume of the fruit juice. 5 Apparatus Usual laboratory apparatus and, in particular, the following. 5.1 Centrifuge, capable of producing a centrifugal acceleration of 370g at the base of the centrifuge tu
22、be (5.3). NOTE. The rotational frequency required to give correct centrifugal acceleration can be calculated from the following equation: a = 11,18 r ( n /1 000) 2 (1) where: a is the centrifugal acceleration; r is the radius of the centrifuge in centimetres, measured from the mid point (the centrif
23、uge axis) to the bottom of the centrifuge tube when swung out; n is the rotational frequency per minute. example: r = 19,5 and a = 370 then: 370 = 11,18 19,5 2 n 1 000 n = 1 000 = 1 302 (2) 370 11,18 19,5 5.2 Magnetic stirrer 5.3 Petroleum tubes, with graduations for 50 ml samples (e.g. Heraeus type
24、 3113 1) or centrifuge tubes (10 ml) with conical base and 0,1 ml graduations. 6 Procedure 6.1 Preparation of the test sample Normally products shall not be pre-treated, however, dilution may be necessary, and their analysis by this method shall be on a volumetric basis. The analysis of concentrated
25、 products may also be carried out on a volumetric basis, after dilution to a known relative density. In this case, the relative density shall be indicated. Mix cloudy samples well before dilution. 6.2 Test procedure Place the fruit juice (10 ml or 50 ml) or the correspondingly diluted concentrate in
26、 the centrifuge tube (5.3) and centrifuge it at a centrifugal acceleration of 370g for 10 min. 7 Calculation The centrifuged pulp may lie unevenly in the tube. Therefore, measure the highest and lowest point of the pulp in each tube, record the mean and calculate the pulp volume in percent. If a con
27、centrated product has been diluted to single strength, report the relative density of the single strength sample. Report the pulp volume in percentage (V/V) to one decimal place.Page 4 EN 12134 : 1997 BSI 1998 Table B.1 Sample A Number of laboratories retained after eliminating outliers Number of ou
28、tliers (laboratories) Number of accepted results 12 1 74 Mean value (x) (%) (V/V) 7,6 Repeatability standard deviation (s r ) (%) (V/V) Repeatability relative standard deviation (RSD r ) (%) 0,309 4,1 Repeatability limit (r) (%) (V/V) 0,9 Reproducibility standard deviation (s R ) (%) (V/V) Reproduci
29、bility relative standard deviation (RSD R ) (%) 0,733 9,6 Reproducibility limit (R) (%) (V/V) 2,1 8 Precision Details of the inter-laboratory test on the precision of the method are summarized in annex B. The values derived from the inter-laboratory test may not be applicable to analyte concentratio
30、n ranges and matrices other than given in annex B. 8.1 Repeatability The absolute difference between two single results found on identical test material by one operator using the same apparatus within the shortest feasible time interval will exceed the repeatability limit r in not more than 5 % of t
31、he cases. For orange juice the value is: r = 0,9 % (V/V). 8.2 Reproducibility The absolute difference between two single test results on identical test material reported by two laboratories will exceed the reproducibility limit R in not more than 5 % of the cases. For orange juice the value is: R =
32、2,1 % (V/V). 9 Test report The test report shall contain the following data: all information necessary for the identification of the sample (kind of sample, origin of sample, designation); a reference to this European Standard; the date and type of sampling procedure (if known); the date of receipt;
33、 the date of test; the test results and units in which they have been expressed; whether the repeatability of the method has been verified; any particular points observed in the course of the test; any operations not specified in the method or regarded as optional, which might have affected the resu
34、lts. Annex A (informative) Bibliography Koch J. and Hess D. Determination of falsified orange juice, Deutsche Lebensmittelrundschau 67 (6), 185195 (1971) Quality Control Manual for Citrus Processing Plants, pp. 47 49 Intercit, Ins. 1975 South Tenth Street, Safety Harbor, Florida 33572 Determination
35、of centrifugable pulp: No. 60, 1991. In: The collected Analyses of the International Federation of Fruit Juice Producers. Loose-leaf edition, as of 1996 Zug: Swiss Fruit Union Annex B (informative) Statistical results of the inter-laboratory test In accordance with ISO 5725 : 1986, the following par
36、ameters have been defined in an inter-laboratory test. (For literature pertaining to the method see annex A). The test was conducted by the International Fruit Union, Paris, France: Year of inter-laboratory Number of laboratories Number of samples Sample types. A orange juice 1989 13 1blankBSI 389 C
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