BS 6248-1-1982 Caseins and caseinates - General introduction including preparation of laboratory samples《酪朊及酪朊酸盐 第1部分 总则(包括试验室样品制备)》.pdf

1、BRITISH STANDARD BS 6248-1: 1982 Caseins and caseinates Part 1: General introduction, including preparation of laboratory samples UDC 637.147.2.04:543BS6248-1:1982 This British Standard, having been prepared under the direction of the Dairying Standards Committee, was published under the authority o

2、f the Board of BSI and comes into effect on 30June1982 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference DAC/3 Draft for comment 81/53484 DC ISBN 0 580 12745 1 Cooperating organizations The Dairying Standards Committee, under whose direction this Briti

3、shStandard was prepared, consists of representatives from the following: Commonwealth Bureau of Dairy Science and Technology Creamery Proprietors Association* Dairy Trade Federation Department of Health and Social Security Department of Industry (Laboratory of the Government Chemist)* Institute of F

4、ood Science and Technology Intervention Board for Agricultural Produce* Joint Committee of the Milk Marketing Board and the Dairy Trade Federation* Milk Marketing Board* Milk Marketing Board for Northern Ireland* Milking Machine Manufacturers Association Ministry of Agriculture, Fisheries and Food N

5、ational Farmers Union National Institute for Research in Dairying* Office of the High Commissioner for New Zealand Process Plant Association Royal Association of British Dairy Farmers* Scottish Dairy Trade Federation Ltd. Scottish Milk Marketing Board Society of Chemical Industry* Society of Dairy T

6、echnology* United Kingdom Dairy Association West of Scotland Agricultural College The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Bri

7、tish Manufacturers of Milk Powder Association of Condensed Milk Manufacturers Association of Public Analysts British Food Manufacturing Industries Research Association Department of Agriculture (Government of Northern Ireland) Hannah Research Institute Ice Cream Alliance Limited Royal Society of Che

8、mistry University of Reading Amendments issued since publication Amd. No. Date of issue CommentsBS6248-1:1982 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Preparation of laboratory samples 1 5 Rounding of numbers 1 Pu

9、blications referred to Inside back coverBS6248-1:1982 ii BSI 12-1999 Foreword This combined revision of BS 1416 and BS 1417 has been prepared under the direction of the Dairying Standards Committee. In this third revision of the standards, the various methods of analysis are described in individual

10、Parts, which will be published separately in a loose-leaf format. BS 1416:1962 and BS1417:1963 will be withdrawn after all the Parts of the present standard which collectively supersede them have been published. The order of publication of these Parts has no technical significance and is mainly depe

11、ndent on progress made in joint working groups of the International Organization for Standardization (ISO) and the Association of Official Analytical Chemists (AOAC) in developing International Standards that can be converted to British Standards. This British Standard will be published initially in

12、 eight Parts as follows: Part 1: General introduction, including preparation of laboratory samples; Part 2: Method for determination of “fixed ash” of caseins (reference method); Part 3: Method for determination of ash of rennet caseins and caseinates (reference method); Part 4: Method for determina

13、tion of pH (reference method); Part 5: Method for determination of free acidity of caseins (reference method); Part 6: Method for determination of lactose content (photometric method); Part 7: Method for determination of protein content (reference method); Part 8: Method for determination of water c

14、ontent (reference method). 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 of pag

15、es This document comprises a front cover, an inside front cover, pages i and ii, pages1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.

16、BS6248-1:1982 BSI 12-1999 1 1 Scope This Part of this British Standard gives general instructions on the preparation of laboratory samples to be read in conjunction with each of the methods described in the other Parts. 2 References The titles of the publications referred to in this Part of this Bri

17、tish Standard are listed on the inside back cover. 3 Definitions For the purposes of this British Standard, the following definitions apply. 3.1 casein product obtained by washing, drying and grinding (if required) the casein coagulum resulting from the action of acid or rennet or other suitable enz

18、yme(s) on skimmed milk 3.2 caseinate Product obtained by dispersing washed acid casein coagulum or acid casein in an alkali solution, and heat treating (if required) and spray-drying or roller-drying the caseinate dispersion. 4 Preparation of laboratory samples 4.1 Selection of units for sampling. F

19、or a recommended scheme for the selection of units to prepare or obtain laboratory samples for analysis, see BS 809:1974, Appendix B in particular. A final scheme for the selection of units awaits completion of an International Standard on this subject by an IDF/ISO/AOAC working group. Meanwhile, th

20、e procedures given for rennet casein in clause 3 of BS1416:1962 and for acid casein in clause 3 of BS1417:1963 should be followed in respect of those products. 4.2 Sampling techniques. For a description of sampling techniques, see BS 809:1974, clause 5 in particular. NOTEA guide on sampling techniqu

21、es, on which the revision of BS 809 will be based, is being prepared by an IDF/ISO/AOAC working group. Samples taken from bulk containers shall be transferred to suitable air-tight containers of a capacity such that these containers are no more than three-quarters filled, to allow the laboratory sam

22、ples to be thoroughly mixed by rotating and inverting the containers. Any laboratory sample which on receipt is not in a suitable air-tight container as specified in BS 809 shall be noted and reported. 5 Rounding of numbers The method of rounding numbers shall be as specified in BS 1957. NOTEFor exa

23、mple, if 95.14, 95.15, 95.25 and 95.16 are to be rounded to the nearest 0.1, the rounded numbers are95.1,95.2,95.2 and 95.2 respectively, i.e. where 5 occurs in the second decimal place, the rounding is to the nearest even number in the first decimal place.2 blankBS6248-1:1982 BSI 12-1999 Publicatio

24、ns referred to BS 809, Methods for sampling milk and milk products. BS 1416, Methods for the sampling and analysis of rennet casein. BS 1417, Methods for the sampling and analysis of acid casein. BS 1957, Presentation of numerical values (fineness of expression; rounding of numbers). BS 6248-1: 1982

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