BS EN ISO 11747-2012 Rice Determination of rice kernel resistance to extrusion after cooking《米 烹饪后稻米籽粒耐挤制测定》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 11747:2012Rice Determination of ricekernel resistance to extrusionafter cooking (ISO 11747:2012)BS EN ISO 11747:2012 BRITISH STANDARDNational forewordThis British Stand

2、ard is the UK implementation of EN ISO11747:2012.The UK participation in its preparation was entrusted to TechnicalCommittee AW/4, Cereals and pulses.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the

3、necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 66350 5ICS 67.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was

4、 published under the authority of theStandards Policy and Strategy Committee on 31 August 2012.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11747 August 2012 ICS 67.060 English Version Rice - Determination of rice kernel resistance to

5、extrusion after cooking (ISO 11747:2012) Riz - Dtermination de la rsistance lextrusion des grains de riz aprs cuisson (ISO 11747:2012) Reis - Bestimmung des Extrusionswiderstandes von Reiskorn nach dem Kochen (ISO 11747:2012) This European Standard was approved by CEN on 31 July 2012. CEN members ar

6、e 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 national standards may be obtained on application to

7、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 language and notified to the CEN-CENELEC Management Ce

8、ntre 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, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithua

9、nia, 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 Management Centre: Avenue Marnix 17, B-1000 Brussels

10、 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11747:2012: EBS EN ISO 11747:2012EN ISO 11747:2012 (E) 3 Foreword This document (EN ISO 11747:2012) has been prepared by Technical Committee ISO/TC 34 “Food products“ in col

11、laboration with Technical Committee CEN/TC 338 “Cereal and cereal products” 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 endorsement, at the latest by February 2013, and conflictin

12、g national standards shall be withdrawn at the latest by February 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to t

13、he CEN/CENELEC Internal Regulations, the national standards organizations of the following countries 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,

14、Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 11747:2012 has been approved by CEN as a EN ISO 11747:2012 without

15、 any modification. BS EN ISO 11747:2012ISO 11747:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope 12 Normative references . 13 Terms and definitions . 14 Principle . 15 Apparatus 16 Reagents 27 Sampling 28 Procedure 38.1 Preparation of the test sample . 38.2 Determination . 39

16、 Calculation and expression of results . 49.1 Calculation 49.2 Expression of results . 410 Precision 410.1 Interlaboratory test . 410.2 Repeatability . 410.3 Reproducibility . 411 Test report . 4Annex A (informative) Example of rice extrusion for the determination of resistance to extrusion 6Annex B

17、 (informative) Results of interlaboratory test 8Bibliography .10BS EN ISO 11747:2012ISO 11747:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally

18、carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the wo

19、rk. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare Intern

20、ational Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the

21、elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 11747 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals and pulses.iv ISO 2012 All rights reservedBS EN ISO 11747:

22、2012INTERNATIONAL STANDARD ISO 11747:2012(E)Rice Determination of rice kernel resistance to extrusion after cooking1 ScopeThis International Standard specifies a method for the determination of resistance to extrusion of milled rice kernels, parboiled or not parboiled, after cooking under specified

23、conditions.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 712, Cereals

24、and cereal products Determination of moisture content Reference methodISO 7301, Rice Specification3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 7301 and the following apply.3.1cooked ricerice brought into contact with hot liquids with the intention

25、of making it suitable for consumption3.2resistance to extrusionease of pushing cooked rice through a perforated plate using compression and shearNOTE An example of suitable perforated plate is the Ottawa cell.1)4 PrincipleMeasurement of the force required to extrude cooked rice through a perforated

26、plate.5 ApparatusUsual laboratory apparatus and, in particular, the following.5.1 Beakers, borosilicate glass, capacity of 100 ml.5.2 Cooking container, with a non-hermetic lid and a perforated plate on which the beakers (5.1) are placed. The level of water in the cooking container shall be such tha

27、t it does not rise above the perforated plate during boiling, ensuring that cooking occurs exclusively by steam.5.3 Sample divider,2)conical sampler or multiple-slot sampler with a distribution system, or other equivalent equipment.1) The Ottawa cell is an example of a suitable product available com

28、mercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of this product.2) Some sample dividers are described in ISO 24333.2 ISO 2012 All rights reserved 1BS EN ISO 11747:2012ISO 11747:2012(E)5.4 Heat source, suitable to allow

29、water in the cooking container (5.2) to boil in a vigorous and steady way.5.5 Balance, capable of being read to the nearest 0,1 g.5.6 Glass rod.5.7 Watch-glasses, 6 cm in diameter.5.8 Dynamometer, able to work under compression, at a constant speed of 10 cm/min, equipped with the devices specified i

30、n 5.8.1 and 5.8.2.5.8.1 Loading cell, with a loading capacity of at least 50 kg.5.8.2 Extrusion cell, see Figures A.1 and A.2, consisting of the components specified in 5.8.2.1 to 5.8.2.3.5.8.2.1 Parallelepiped, with the following characteristics:a) integral with the dynamometer;b) about 20 cm high;

31、c) with a hole of area 7,5 cm2in the centre;d) with a basis area adequate to house the hole mentioned in c) and a removable plate intersecting the parallelepiped at about one-third of its height.5.8.2.2 Perforated plate, 3 mm thick, with holes of 6,0 mm in diameter and a wheelbase of 7,0 mm (centre

32、to centre), suitable for insertion into the parallelepiped (5.8.2.1).5.8.2.3 Piston, with the following characteristics:a) suitable for the loading cell (5.8.1);b) 20 cm high;c) with a section base having a minimum tolerance (about 0,5 mm) that allows it to run freely within the parallelepiped hole

33、(5.8.2.1).5.9 Timer.5.10 Spatula.5.11 Plastic bags, or other vessels able to contain 17 g of cooked rice while preventing its dehydration.5.12 Data entry system, with a sample rate of at least 5/s.6 Reagents6.1 Deionized water, or distilled water.7 SamplingSampling is not part of the method specifie

34、d in this International Standard. A recommended sampling method is given in ISO 24333.22 ISO 2012 All rights reservedBS EN ISO 11747:2012ISO 11747:2012(E)It is important the laboratory receive a truly representative sample which has not been damaged or changed during transport or storage.8 Procedure

35、8.1 Preparation of the test sample8.1.1 Carefully mix the laboratory sample to make it as uniform as possible.8.1.2 Determine the laboratory sample moisture content according to ISO 712. The acceptability range is a mass fraction of (13,0 1,0) %.8.1.3 If the moisture content differs, condition the l

36、aboratory sample at room temperature until moisture lies within the acceptability range (8.1.2).8.1.4 Proceed to reduce the laboratory sample, if necessary, using a sample divider (5.3) to a quantity of about 50 g to obtain the test sample.8.2 Determination8.2.1 HeatingAdjust the heat source (5.4) s

37、o that the water vigourously and steadily boils in the cooking container (5.2).8.2.2 Sample preparation for cookingPrepare two beakers (5.1) for each test, put in each one 20 g of milled rice taken from the test sample (8.1.4) and weighed with the balance (5.5) to the nearest 0,1 g, add 38 ml of dei

38、onized water (6.1). Carefully stir with the glass rod (5.6) and cover the beakers with watch-glasses (5.7).8.2.3 CookingPlace the two beakers prepared according to 8.2.2 on the perforated plate in the cooking container (5.2) and replace the lid immediately. Start the timer (5.9). Remove the heat sou

39、rce after 20 min and allow to stand for 10 min. Remove the beakers from the cooking container and place them upside down on the watch-glasses in a room at an ambient temperature of 20 C to 25 C . Allow to cool to room temperature for at least 1 h.8.2.4 Dynamometer adjustmentAdjust the dynamometer (5

40、.8) and the data entry system (5.12) according to the manufacturers instructions, checking the response of the loading cell (values between 0 kg and 15 kg) and the speed of the movement (10 cm/min).8.2.5 Dynamometer measurementsRemove the cylinder of cooked rice from one of the beakers, split it lon

41、gitudinally with a spatula (5.10) to obtain three portions of about 17 g each and store them in plastic bags (5.11) to prevent dehydration until the time of measurement.Place a portion in the parallelepiped hole (5.8.2.1), allow the piston (5.8.2.3) to descend, and continuously record (5.12) the for

42、ce applied during the extrusion of the mass of cooked rice.Calculate the mean force applied during the step corresponding to the plateau of the extrusion plot.Proceed in the same way with the other portions.Remove the rice from the second beaker and proceed as with the first. ISO 2012 All rights res

43、erved 3BS EN ISO 11747:2012ISO 11747:2012(E)Between measurements on portions from the same test sample, it is not necessary to wash the extrusion cell, perforated plate and piston. Washing (with tap water and brush only) is necessary when passing from one sample to another. It is suggested that any

44、excess water on the extrusion cell, perforated plate and piston after washing be wiped away with a damp cloth.9 Calculation and expression of results9.1 CalculationCalculate the arithmetic mean of the six measurements done on the test sample and divide it by the area of the parallelepiped hole (7,5

45、cm2).9.2 Expression of resultsReport the mean value in kg/cm2, to two decimal places.10 Precision10.1 Interlaboratory testDetails of an interlaboratory test on the precision of the method is summarized in Annex B. It is possible that the values derived from this interlaboratory test are not applicab

46、le to other types of rice and mixtures of other varieties.10.2 RepeatabilityThe absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of t

47、ime, will in not more than 5 % of cases be greater than the repeatability limit, r, of 0,056 kg/cm2for non-parboiled milled rice; 0,082 kg/cm2for parboiled milled rice.10.3 ReproducibilityThe absolute difference between two single test results, obtained using the same method on identical test materi

48、al in different laboratories with different operators using different equipment, will in not more than 5 % of cases be greater than the reproducibility limit, R, of 0,107 kg/cm2for non-parboiled milled rice; 0,219 kg/cm2for parboiled milled rice.11 Test reportThe test report shall contain at least t

49、he following information:a) all information necessary for the complete identification of the sample;b) the sampling method used, if known;c) the test method used, with reference to this International Standard (ISO 11747:2012);d) all operating details not specified in this International Standard, or regarded as optional, together with details of any incidents which may have influenced the test result(s);e) the test result(s) obtained;4 ISO 2012 All rights reservedBS EN ISO 11747:2012ISO 11747:2012(E)f) if the repeatability has been c