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1、BRITISH STANDARD CONFIRMED FEBRUARY 1999 BS 770-1:1986 Methods for Chemical analysis of cheese Part 1: General introduction UDC 637.3.074 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 770-1:1986 This Briti
2、sh Standard, having been prepared under the direction of the Dairying Standards Committee, was published under the authority of the Board of BSI and comes into effect on 28 February 1986 BSI 01-2000 First published January 1938 First revision May 1952 Second revision October 1963 First Part revision
3、 February 1976 Second Part revision February 1986 The following BSI references relate to the work on this standard: Committee reference DAC/3 Draft for comment 85/51848 DC ISBN 0 580 15052 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by th
4、e Dairying Standards Committee (DAC/-) to Technical Committee DAC/3, upon which the following bodies were represented: AFRC Food Research Institute, Reading Association of British Preserved Milk Manufacturers Association of Public Analysts Association of Public Analysts of Scotland Creamery Propriet
5、ors Association Dairy Trade Federation Department of Trade and Industry (Laboratory of the Government Chemist) Ice Cream Alliance Limited Intervention Board for Agricultural Produce Joint Committee of the Milk Marketing Board and the Dairy Trade Federation Milk Marketing Board Milk Marketing Board f
6、or Northern Ireland Ministry of Agriculture, Fisheries and Food Royal Association of British Dairy Farmers Royal Society of Chemistry Society of Chemical Industry Society of Dairy Technology University of Reading Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: London
7、 South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 770-1:1986 BSI 01-2000i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Determinations supplementary to those in BS 7701 3Sampling1 4Preparation of sampl
8、e1 5Reagents1 6Rounding of numbers1 7Test reports1 Publications referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 770-1:1986 ii BSI 01-2000 Foreword This Part of BS 770 has been pr
9、epared under the direction of the Dairying Standards Committee. It supersedes BS 770-1:1976 which is withdrawn. BS 770 was first published in 1938 and revised in 1952 and 1963. Later it was decided to revise the standard in Parts to make easier the continuing task of implementing, in the form of Bri
10、tish Standards, relevant methods prepared by subcommittee 5, Milk and milk products, of Technical Committee 34, Agricultural food products, of the International Organization for Standardization. The first Parts of the multi-part revision were published in 1976, and it is expected that the task of re
11、placing the previous edition will be complete in 1986, with the publication of Part 8. When that Part is published, BS 770:1963 will be withdrawn. A list of Parts of BS 770 published or in preparation is given below. The methods in this revision have been aligned as far as possible with the correspo
12、nding ISO methods and attention is drawn to this in the appropriate Parts. Part 1: General introduction; Part 2: Determination of water content (reference and routine methods); Part 3: Determination of fat content (reference method); Part 4: Determination of chloride content. Potentiometric titratio
13、n method; Part 5: Determination of pH value; Part 6: Determination of total phosphorus content. Molecular absorption spectrometric method; Part 7: Determination of citric acid content (reference method); Part 8: Determination of nitrogen content (reference method)1); Part 9: Determination of nitrate
14、 and nitrates content. Cadmium reduction and photometry method; Part 10: Determination of total solids content (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. Comp
15、liance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may h
16、ave had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In preparation. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 770-1:1986 BSI 01-20001 1 Scope Th
17、is Part of BS 770 gives general instructions which need to be read in conjunction with each of the test methods described in other Parts (published separately). NOTE 1The method of preparation of the sample is a more detailed version of the method described in various International Standards on the
18、analysis of cheese (e.g. ISO 2962). NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Determinations supplementary to those in BS 770 Reference should be made to the following methods in respect of these determinations. Determination of fat (Ger
19、ber method): BS 696-1 and BS 696-2 Estimation and differentiation of nisin in processed cheese: BS 4020 Detection of foreign fats: a) vegetable fat (phytosteryl acetate method): BS 5475-1; b) vegetable fat (GLC method of sterols): BS 5475-2. 3 Sampling Carry out the sampling in accordance with the m
20、ethods described for cheese in BS 809. 4 Preparation of sample2) 4.1 Before the analysis, remove any inedible surface layer of the cheese in such a way as to obtain a sample representative of the cheese as it is usually consumed. 4.2 Comminute the sample either by means of an appropriate device, e.g
21、. a suitable grater or mortar and pestle, or by cutting it into small pieces and then quickly mix the resulting mass. If necessary, repeat the operation. Clean the device after each sample. If the sample cannot be so comminuted, mix it thoroughly by intensive kneading. If there is any visible eviden
22、ce of separation of moisture or fat, an attempt should be made to reincorporate these into the prepared sample. In such cases the results of analysis may be unreliable and an appropriate note should be made in the test report. 4.3 Immediately transfer the prepared sample to an airtight container of
23、minimum size. Carry out the analysis as soon as possible, preferably on the same day as sample preparation. If delay is unavoidable, ensure that the sample is stored in such a way that loss of moisture from the cheese is prevented. 5 Reagents Unless otherwise stated, use reagents which are of recogn
24、ized reagent grade and, wherever the use of water is required, use distilled or demineralized water complying with the requirements of BS 3978. 6 Rounding of numbers In the various Parts of BS 770, use the method of rounding numbers specified in BS 1957. NOTEFor example, if 95.14, 95.15, 95.25 and 9
25、5.16 are to be rounded to the nearest 0.1, the rounded numbers are 95.1, 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. 7 Test reports Include the following in the test reports: a) result of e
26、ach test carried out, expressed in accordance with the clause headed “expression of result” in the appropriate Part of BS 770; b) full reference to the method of test e.g. “Part 2 (reference method) of BS 770”; c) note of any special factor that may have affected the result; d) details of the sample
27、 identity. Copper content:BS 6394-1 Iron content:BS 6394-2 Lead content:BS 6394-3a a In preparation. 2) The techniques to be used for each particular type of cheese are indicated in the individual international cheese standards being prepared under the FAO/WHO Code of Principles concerning milk and
28、milk products. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 blank Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI B
29、S 770-1:1986 BSI 01-2000 Publications referred to BS 696, Gerber method for the determination of fat in milk and milk products. BS 696-1, Apparatus. BS 696-2, Methods. BS 809, Methods for sampling milk and milk products. BS 1957, Presentation of numerical values (fineness of expression; rounding of
30、numbers). BS 3978, Water for laboratory use. BS 4020, Methods for the estimation and differentiation of nisin in processed cheese. BS 5475, Methods for detection of foreign fats in dairy products. BS 5475-1, Detection of vegetable fat by the phytosteryl acetate test. BS 5475-2, Detection of vegetabl
31、e fat by gas-liquid chromatography of sterols (reference method). BS 6394, Trace elements in milk and milk products. BS 6394-1, Method for the determination of copper content (reference method). BS 6394-2, Method for the determination of iron content (reference method). BS 6394-3, Method for the det
32、ermination of lead content (reference method)3). ISO 2962, Cheese and processed cheese products Determination of phosphorus content (Reference method). 3) In preparation. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:49:45 GMT+00:00 2006, Uncontrolled Copy,
33、 (c) BSI BS 770-1:1986 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revi
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40、. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free us
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