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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BSISO6646:2000 ICS 67.060
2、 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Rice Determination of the potential milling yield from paddy and husked rice Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared
3、under the direction of the Consumer Products and Services Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 April 2000 BSI 04-2000 ISBN 0 580 34502 5 BS ISO 6646:2000 Amendments issued since publication Amd. No.DateComments National foreword T
4、his British Standard reproduces verbatim ISO 6646:2000 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee AW/4, Cereals and pulses, which has the responsibility to: aid enquirers to understand the text; present to the responsib
5、le international/European committee any enquiries on the interpretation, 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 reques
6、t to its secretary. Cross-references The British Standards which implement 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
7、 Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary
8、of pages This document comprises a front cover, an inside front cover, the ISO title page, ii to iv, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Mon
9、Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 6646:2000(E) INTERNATIONAL STANDARD ISO 6646 Second edition 2000-02-15 Rice Determination of the potential milling yield from paddy and from husked rice Riz Dtermination des rendements lusinage partir du riz paddy et du
10、riz dcortiqu Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) ii? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) ?iii Foreword ISO (the Internationa
11、l Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been es
12、tablished has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardi
13、zation. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. 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 7
14、5 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 6646 was prepared b
15、y Technical Committee ISO/TC 34,Agricultural food products, Subcommittee SC 4,Cereals and pulses. This second edition cancels and replaces the first edition (ISO 6646:1984), which has been revised and completed with precision data from an interlaboratory study. Annex A forms a normative part of this
16、 International Standard. Annex B is for information only. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) iv? Introduction The milling yields obtained from abrasive testing mills of the same model, although with differing ad
17、justments, may vary more widely than those obtained from different types of abrasive testing mill. This International Standard details a method to standardize the determination of milling yield, to ensure that results obtained by different operators using abrasive test mills are comparable. A list o
18、f standards related to this International Standard is given in the bibliography. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARD?ISO 6646:2000(E) ?1 Rice Determination of the potential milling yield from paddy and from
19、 husked rice 1?Scope This International Standard specifies a laboratory method for the determination of the yield of husked rice obtained from paddy or parboiled paddy (Oryza sativa L.), and for the determination of the yield of milled head rice obtained from paddy or parboiled paddy, or from husked
20、 rice or husked parboiled rice. This International Standard is only applicable to abrasive milling equipment. 2?Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references,
21、 subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated reference
22、s, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 712,Cereals and cereal products Determination of moisture content Routine reference method. ISO 7301,Rice Specification. 3?Terms and definiti
23、ons For the purposes of this International Standard, the terms and definitions given in ISO 7301 and the following apply. 3.1 husked rice yield amount of husked rice obtained from paddy 3.2 milled rice yield amount of milled rice (head rice, broken kernels and chips) obtained from paddy or husked ri
24、ce 3.3 milled head rice yield amount of milled head rice obtained from paddy or husked rice 4Principle The husk is mechanically removed from paddy. The resultant husked rice is then weighed. Next, the pericarp and germ are mechanically removed from the husked rice to a fixed reduction in mass and th
25、e resulting milled head rice is weighed. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) 2? 5?Apparatus Usual laboratory apparatus and, in particular, the following. 5.1Sample divider, conical sampler or multiple-slot sample
26、r with distribution system. 5.2Testing husker, suitable for removal of the husk from paddy without damaging the kernels. 5.3Abrasive testing mill, suitable for removal of the pericarp and germ from husked rice. 5.4Tweezers. 5.5Small bowls. 5.6Balance, capable of weighing to the nearest 0,01 g. 6?Sam
27、pling Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 13690 1. It is important the laboratory receive a sample which is truly representative and has not been damaged or changed during transport or storage. 7?Preparation of te
28、st sample The laboratory sample shall have a mass of not less than 1,5 kg. Carefully mix the laboratory sample to make it as homogeneous as possible, then reduce it through a sample divider (5.1) to obtain the test sample. Determine the moisture content of the test sample according to ISO 712. The a
29、cceptance range is a mass fraction of (13,0 ? 1,0) %. If the moisture content is outside the acceptance range, the laboratory sample should be conditioned at ambient temperature and humidity for a sufficient period to obtain a moisture content within the specified range. 8?Procedure 8.1? Adjustment
30、of equipment 8.1.1?Testing husker adjustment Adjustment of the test equipment shall be carried out prior to the determination. The testing husker (5.2) shall be considered correctly adjusted when, subsequent to dehusking of rice samples with grain dimensions similar to those of the laboratory sample
31、, the following are not present: ?husked rice with damage to the pericarp, ?grains of paddy or husked rice in the separated husk, ?husk particles in the husked rice. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) ?3 8.1.2?T
32、esting mill adjustment Adjustment of the test equipment shall be carried out prior to the determination. Adjust the testing mill (5.3) by milling rice samples of grain dimensions similar to those of the laboratory sample in order to remove a mass fraction of (f ? 0,5) % of the husked rice so that th
33、e mass of milled head rice minus the mass of milled whole kernels is u 3,0 % (head rice includes whole kernels). The value of f shall be agreed by the parties involved. 8.2? Determination of husked rice yield (see Figure A.1 in annex A) Take the test sample and divide it to give a portion suitable f
34、or the equipment. Weigh it to the nearest 0,01 g. A minimum of 200 g is recommended. Spread the paddy and remove any extraneous matter. Dehusk the paddy in the testing husker (5.2). Any grains of paddy which are not dehusked shall be separated from the husked rice and passed through the testing husk
35、er again. Weigh the total yield of husked rice to the nearest 0,01 g. 8.3? Determination of milled head rice yield 8.3.1?Starting from paddy or parboiled paddy (see Figure A.2) 8.3.1.1Operate according to 8.2 to obtain the husked rice. Divide the husked rice to give a portion suitable for the equipm
36、ent. Weigh and record the mass to nearest 0,01 g. A minimum of 100 g is recommended. 8.3.1.2Thoroughly clean the testing mill (5.3). Introduce the husked rice sample and mill it for the time necessary to remove the mass fraction (f ? 0,5) % of its total mass. The milling time has to be predetermined
37、 by trials on each test sample. Weigh the obtained milled rice and record the mass to the nearest 0,01 g. Separate the head rice from the broken kemels and place the two fractions in separate bowls. Weigh the head rice and record the mass to the nearest 0,01 g. 8.3.2?Starting from husked rice or fro
38、m husked parboiled rice (see Figure A.3) 8.3.2.1Take the test sample and divide it to give a portion suitable for the equipment. Weigh it to the nearest 0,01 g. A minimum of 100 g is recommended. Spread the husked rice and remove any extraneous matter. 8.3.2.2Continue as given in 8.3.1.2. 9?Expressi
39、on of results Calculate the results as quotients to four decimal places according to Table 1. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) 4? Table 1 Calculation of milling yields Mass (m) of test portion starting from Yi
40、eld paddy husked ricea Y0(husked rice)?my/mxmz/ my Y1(milled rice)?m1/ mwm1/ mz Y2(milled head rice)?m2/ mwm2/ mz a Including extraneous matter. Refer to the scheme of the procedure given in annex A (Figure A.1 or A.2 for paddy; Figure A.3 for husked rice). Express the results of yields as percentag
41、es, referred to the starting material, as follows: ?potential yield of husked rice (Yh) %100? 0h YY ?potential yield of milled rice (Ym) YY?f m0 %?()100 ?potential yield of milled head rice (Ymh) % 100 1 20mh Y f YYY ? ? Calculate the results for each category to two decimal places, and report them
42、to the nearest 0,1 %. 10 Precision 10.1 Interlaboratory test Details of an interlaboratory test on the precision of the method are summarized in annex B. The values derived from this interlaboratory test may not be applicable to concentration ranges and matrices other than those given. 10.2 Repeatab
43、ility The 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 time, will in not more than 5 % of cases be greater than the arithmetic
44、 mean of the values for r from the interlaboratory study: ?for husked rice, 1 %; ?for milled head rice, 2 %. 10.3 Reproducibility The absolute differences between two single test results, obtained using the same method on identical test material in different laboratories with different operators usi
45、ng different equipment, will in not more than 5 % of cases be greater than the arithmetic mean of the values for R from the interlaboratory study: Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) ?5 ?for husked rice, 3 %; ?fo
46、r milled head rice, 5 %. 11 Test report The test report shall specify: ?all information necessary for the complete identification of the sample; ?the sampling method used, if known; ?the test method used, with reference to this International Standard; ?all operating details not specified in this Int
47、ernational Standard, or regarded as optional, together with details of any incidents which may have influenced the test result(s); ?the test result(s) obtained; or if the repeatability has been checked, the final quoted result obtained. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17
48、 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) 6? Annex A (normative) Procedure schemes Figure A.1 Starting from paddy or parboiled paddy: yield of husked rice Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) ?7
49、 Figure A.2 Starting from paddy or parboiled paddy: yield of husked rice, milled rice and milled head rice Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:34:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 6646:2000(E) 8? Figure A.3 Starting from husked rice or husked parboiled rice: yield of milled rice and milled head rice Licensed Co