1、BRITISH STANDARDBS EN ISO 11052:2006Durum wheat flour and semolina Determination of yellow pigment contentThe European Standard EN ISO 11052:2006 has the status of a British StandardICS 67.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g4
2、0g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 11052:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2006ISBN 0 580 49001 7National forewordThis British Standard
3、 was published by BSI. It is the UK implementation of EN ISO 11052:2006. It supersedes BS 4317-31:1995 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/4, Cereals and pulses.A list of organizations represented on AW/4 can be obtained on request to it
4、s secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN S
5、TANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 11052August 2006ICS 67.060English VersionDurum wheat flour and semolina - Determination of yellowpigment content (ISO 11052:1994)Farines et semoules de bl dur - Dtermination de la teneuren pigments jaunes (ISO 11052:1994)Hartweizenmehl und Hartweizengrie -
6、 Bestimmung desGehaltes an gelben Pigmenten (ISO 11052:1994)This European Standard was approved by CEN on 3 August 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without
7、any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 language made by
8、 translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece,
9、 Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centr
10、e: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 11052:2006: EForeword This European Standard shall be given the status of a national standard, either by publication of an identicalat th
11、e latest by February 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
12、Ireland, Italy, Latvia, Lithuania, Switzerland and United Kingdom. Endorsement notice The text of ISO 11052:1994 has been approved by CEN as EN ISO 11052:2006 without any modifications.The text of ISO 11052:1994 has been prepared by Technical Committee ISO/TC 34 “Agricultural food products” of the I
13、nternational Organization for Standardization (ISO) and has been taken over as EN ISO 11052:2006 by Technical Committee CEN/TC 338 “Cereal and cereal products“, the secretariat of which is held by AFNOR. text or by endorsement, at the latest by February 2007, and conflicting national standards shall
14、 be withdrawn Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, EN ISO 11052:2006INTERNATIONAL STANDARD IS0 11052 First edition 1994-09-01 Durum wheat flour and semolina - Determination of yellow pigment content Farines et semoules de b/6 dur - D -
15、 easy to clean; - of minimal dead space; - capable of grinding rapidly and uniformly without heating, and avoiding as far as possible contact of the sample with the outside air. 6.2 Spectrometer, capable of operating at a wave- length of 440 nm. 1 EN ISO 11052:20060 IS0 6.3 Erlenmeyer flasks, of cap
16、acity 200 ml, prefera- bly of brown glass, with ground glass stoppers. 6.4 Erlenmeyer flasks, of capacity 100 ml. 6.5 Volumetric flasks, of capacity 10 ml, narrow- necked, with ground glass stoppers. 6.6 Volumetric flasks, of capacities 100 ml and 250 ml, with ground glass stoppers. 6.7 Pipettes, of
17、 capacities 20 ml and 25 ml. 6.8 Watch glass or Petri dish, as cover for the funnel (6.10). water-saturated n-butanol (5.1) to give a homogene- ous suspension. Shake gently in the stoppered flask several times during the first hour. Allow the suspen- sion to stand overnight (16 h to 18 h) at room te
18、m- perature. NOTE 2 If no brown glass flasks are available, protect the stoppered flask from light. The next morning, shake the contents again, the ter completely through the fluted filter paper into a 100 ml Erlenmeyer flask (6.4). To avoid sol loss by evaporation, place the funnel (6.10) on flask
19、and cover it with a watch glass or Petri (6.8). 10.2 Determination 6.9 Filter paper, hard, fluted. 6.10 Funnel. 6.11 Analytical balance, capable of weighing to an accuracy of 0,001 g. 7 Sampling It is important that the laboratory receive a sample which is truly representative and has not been dam-
20、aged or changed during transport or storage. Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in IS0 2170. 8 Preparation of test sample NOTE 1 A comparative study has demonstrated particle size under 0,5 mm is appropriate. that a 9 D
21、etermination of moisture content Determine the moisture content of the test sample in accordance with IS0 712. 10 Determination of yellow pigment 10.1 Preparation of extract In a 200 ml Erlenmeyer flask (6.3), weigh, to the nearest 0,001 g, 10 g of the test sample, ground if necessary (see clause 8)
22、. Disperse it in 50 ml of n fil- 6.9) vent the dish Measure the optical density of the clear filtrate at 440 nm as absorbance, using the spectrometer (6.2). Use unfiltered water-saturated n-butanol for setting-up the instrument and for the blank determi- nations. Read the corresponding p-carotene co
23、ntent from the calibration curve (I 0.4). 10.3 Preparation of standard solution of /I-carotene In a 100 ml one-mark volumetric flask (6.6), weigh, to within 0,001 g, exactly 0,025 g of p-carotene. Dis- solve it in diethyl ether (5.2). Make up to the mark with diethyl ether and mix carefully. Take, u
24、sing a pipette (6.7), 20 ml of this homogeneous solution ( = 5 mg of b-carotene) and place in a 250 ml one- mark volumetric flask (6.6). Make up to the mark with water-saturated n-butanol (5. I ) and mix carefully. Then take, using the pipette, 25 ml of this solution and place in a 100 ml one-mark v
25、olumetric flask (6.6). Make up to the mark with the water-saturated nbutanol and mix carefully. This is the standard sol concentration: ution. It has the following 1 ml = 0,005 mg = 5 gg B-carotene. 10.4 Preparation of calibration curve Prepare suitable dilutions of the standard solution (10.3) with
26、 water-saturated n-butanol in calibrated 10 ml volumetric flasks (6.5) (e.g. from 0,5 ml to 3 ml of standard solution in 10 ml). Measure the absorbance A, of each dilution and es- tablish a calibration curve (/?-carotene in 10 ml of sol- ution as a function of absorbance). 2 EN ISO 11052:20060 IS0 I
27、S0 11052:1994(E) 11 Calculation The yellow pigment content, wp, expressed as milli- grams of b-carotene in 100 g of dry matter, is equal to wp = 5a 100-H where a is the b-carotene content corresponding to the 10 ml extract (equivalent to 2 g of the test sample), in milligrams; H is the moisture cont
28、ent of the test sample, expressed as a percentage by mass. 12 Precision Results of an interlaboratory test are given in annex A. ference between two single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment wit
29、hin a short interval of time, should not be greater than 0,03 mg/lOO g. 12.3 Reproducibility For a yellow pigment content within the range of 0,651 mg/lOO g to 0,754 mg/lOO g, the absolute dif- ference between two single test results, obtained using the same method on identical test material in diff
30、erent laboratories with different operators using different equipment, should not be greater than 0,3 mg/lOO g. 13 Test report The test report shall specify - the method in accordance with which sampling was carried out, if known, 12.1 Accuracy - the method used, Since B-carotene is used for calibra
31、tion but is not present, or is only a minor constituent of the grain endosperm pigments, the resulting values may devi- ate by up to 5 % from the true value. However, as xanthophyl (lutein) is not readily available for cali- bration, this error is unavoidable and is of minor con- sequence. 12.2 Repe
32、atability For a yellow pigment content within the range of 0,651 mg/lOO g to 0,754 mg/lOO g, the absolute dif- - the test result(s) obtained, and - if the repeatability has been checked, the final quoted result obtained. It shall also mention all operating details not specified in this International
33、 Standard, or regarded as optional, together with details of any incidents which may have influenced the test result(s). The test report shall include al for the complete identification I informatio of the sam n necessary Pie . 3 EN ISO 11052:2006IS0 11052:1994(E) Annex A (informative) Results of in
34、terlaboratory test An interlaboratory test, carried out by the International of which carried out four determinations on each Association for Cereal Science and Technology (ICC) sample, gave the statistical results (evaluated in ac- in 1989, in which seven laboratories participated, each cordance wi
35、th IS0 5725) shown in tableA.l. Table A.1 Sample I II III IV V VI Number of laboratories retained after . eliminating outliers 7 7 7 7 7 7 Mean content, mg/lOO d.m.1) g 0,754 0,731 0,697 0,699 0,658 0,651 Standard deviation of repeatability &., mg/lOO g d.m. 0,007 28 0,007 21 0,010 8 0,005 68 0,006
36、05 0,007 36 Coefficient of variation of repeatability, % 0,96 0,99 I,55 0,81 0,92 I,13 Repeatability, 2,83 $, mg/lOO g d.m. 0,020 0,020 0,031 0,016 0,017 0,021 Standard deviation of reproducibility, Sr, mg/lOO g d.m. 0,082 0 0,084 3 0,096 5 0,098 6 0,105 6 0,088 0 Coefficient of variation of reprodu
37、cibility, % IO,83 II,53 13,84 14,24 16,05 13,52 Reproducibility, 2,83 &., mg/lOO g d.m. 0,233 0,238 0,273 0,282 0,299 0,249 1) d.m. = dry matter 4 EN ISO 11052:2006IS0 11052:1994(E) Annex B (informative) Bibliography I IS0 2170: 1980, Cereals and pulses - Sampling of milled products. 2 IS0 5725:1986
38、, Precision of test methods - Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. EN ISO 11052:2006BS EN ISO 11052:2006BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is the independent national body responsible for prepa
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