《ISO-6646-2000.pdf》由会员分享，可在线阅读，更多相关《ISO-6646-2000.pdf（16页珍藏版）》请在三一文库上搜索。
1、Reference number ISO 6646:2000(E) ISO 2000 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 riz dcortiqu Copyright International Organization
2、for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) PDF disclaimer This PDF file may contain embedded typefaces. In acc
3、ordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobes
4、licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for pri
5、nting. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2000 All rights reserved. Unless otherwise specified, no part of this
6、 publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 ? CH-12
7、11 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 734 10 79 E-mail copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO 2000 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not fo
8、r Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) ISO 2000 All rights reservediii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The w
9、ork 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 established has the right to be represented on that committee. International organizations, governmental and non-govern
10、mental, in liaison with ISO, also take part in the work. 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 3. Dra
11、ft 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 elements of this Inte
12、rnational 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 by Technical Committee ISO/TC 34,Agricultural food products, Subcommittee SC 4,Cereals and pulses. This second edition
13、 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 International Standard. Annex B is for information only. Copyright International Organization for Standardization Pr
14、ovided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) iv ISO 2000 All rights reserved Introduction The milling yields obtained from abrasive te
15、sting mills of the same model, although with differing adjustments, 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 ope
16、rators using abrasive test mills are comparable. A list of standards related to this International Standard is given in the bibliography. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/
17、21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARDISO 6646:2000(E) ISO 2000 All rights reserved1 Rice Determination of the potential milling yield from paddy and from husked rice 1Scope This International Standard specifies a laboratory
18、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 rice or husked parboiled rice. This International Standard is only appl
19、icable to abrasive milling equipment. 2Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do
20、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 references, the latest edition of the normative document referred to applies. Memb
21、ers 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. 3Terms and definitions For the purposes of this International Standard, the terms and definit
22、ions 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 rice 3.3 milled head rice yield amount of milled head rice obtained from pad
23、dy 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 the resulting milled head rice is weighed. Copyright International Organizat
24、ion for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) 2 ISO 2000 All rights reserved 5Apparatus Usual laboratory appa
25、ratus and, in particular, the following. 5.1Sample divider, conical sampler or multiple-slot sampler 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 hus
26、ked rice. 5.4Tweezers. 5.5Small bowls. 5.6Balance, capable of weighing to the nearest 0,01 g. 6Sampling 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 r
27、epresentative and has not been damaged or changed during transport or storage. 7Preparation of test 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 obta
28、in the test sample. Determine the moisture content of the test sample according to ISO 712. The acceptance 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 suffic
29、ient period to obtain a moisture content within the specified range. 8Procedure 8.1Adjustment of equipment 8.1.1Testing 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
30、 to dehusking of rice samples with grain dimensions similar to those of the laboratory sample, 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. Copyright International Organization for
31、Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) ISO 2000 All rights reserved3 8.1.2Testing mill adjustment Adjustment o
32、f 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 the mass of milled head rice minus th
33、e 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. 8.2Determination of husked rice yield (see Figure A.1 in annex A) Take the test sample and divide it to give a portion suitable for the equipment. Weigh it to the nea
34、rest 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 husker again. Weigh the total yield of hu
35、sked rice to the nearest 0,01 g. 8.3Determination of milled head rice yield 8.3.1Starting 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 equipment. Weigh and record the mass to neares
36、t 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 by trials on each test sample. Weigh th
37、e 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. 8.3.2Starting from husked rice or from husked parboiled rice (see Figure A.3)
38、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. 9Expression of results Calculate the results as quo
39、tients to four decimal places according to Table 1. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -
40、,-,- ISO 6646:2000(E) 4 ISO 2000 All rights reserved Table 1 Calculation of milling yields Mass (m) of test portion starting from Yield 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
41、 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 percentages, referred to the starting material, as follows: ?potential yield of husked rice (Yh) %100? 0h YY ?potential yield of milled rice (Ym) YYf m0 %?()100 ?potential yield of
42、 milled head rice (Ymh) % 100 1 20mh Y f YYY ? ? Calculate the results for each category to two decimal places, and report them 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
43、 from this interlaboratory test may not be applicable to concentration ranges and matrices other than those given. 10.2 Repeatability 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 oper
44、ator using the same equipment within a short interval of time, will in not more than 5 % of cases be greater than the arithmetic 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 singl
45、e test results, obtained using the same method on identical test material in different laboratories with different operators using 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: Copyright International O
46、rganization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6646:2000(E) ISO 2000 All rights reserved5 ?for husked rice, 3 %; ?f
47、or 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 In
48、ternational 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. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:07:23 MDTNo reproduction or networking permitted without license from IHS -