1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 3720:2011Black tea Definition and basic requirementsBS ISO 3720:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 3720:2011. It s
2、upersedes BS 6048:1987, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/8, Tea.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provision
3、s of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 66544 8 ICS 67.140.10 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on
4、 31 May 2011.Amendments issued since publicationDate Text affectedBS ISO 3720:2011Reference numberISO 3720:2011(E)ISO 2011INTERNATIONAL STANDARD ISO3720Fourth edition2011-04-15Black tea Definition and basic requirements Th noir Dfinition et caractristiques de base BS ISO 3720:2011ISO 3720:2011(E) CO
5、PYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this 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 bel
6、ow or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 3720:2011ISO 3720:2011(E) ISO 2011 All ri
7、ghts reserved iiiForeword ISO (the International 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 subj
8、ect 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 work. ISO collaborates closely with the International Electrotechnical Commission (IE
9、C) 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 International Standards. Draft International Standards adopted by the technical committ
10、ees 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 document may be the subject of patent rights. ISO shall not be
11、held responsible for identifying any or all such patent rights. ISO 3720 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 8, Tea. This fourth edition cancels and replaces the third edition (ISO 3720:1986), which has been technically revised. It also incorporates the Tech
12、nical Corrigenda ISO 3720:1986/Cor.1:1992 and ISO 3720:1986/Cor.2:2004. BS ISO 3720:2011ISO 3720:2011(E) iv ISO 2011 All rights reservedIntroduction Tea is grown and manufactured in numerous countries of the world and is blended or drunk in many more. Black tea may be produced from tea from one gard
13、en or region or may be a blend of teas from two or more origins. The desired characteristics of a black tea and the resulting liquor depend on many factors including the type of water to be used for brewing, whether the liquor is to be drunk with or without milk or lemon, and on individual tastes. T
14、he objects of this International Standard are to specify the plant source from which black tea is to be manufactured and to set requirements for certain chemical characteristics which, if met, are an indication that the tea has been subjected to recognized good production practice. It is a matter fo
15、r the parties concerned whether to apply the requirements of this International Standard to a consignment or lot of black tea. The quality of teas is usually assessed by tea tasters, who base their judgements on their previous experience of tea from the producing area and their knowledge of national
16、 or regional conditions, and preferences in the consuming country. Account may be taken of characteristics such as the appearance of the tea before preparation of a liquor, the appearance of the infused leaf and the appearance, odour and taste of the liquor. An expert tea taster can assess whether a
17、 tea would be unlikely to comply with the chemical requirements. Thus, in practice, time and expense can be saved by submitting teas for chemical analysis only if the tea is considered “suspect” by a tea taster. BS ISO 3720:2011INTERNATIONAL STANDARD ISO 3720:2011(E) ISO 2011 All rights reserved 1Bl
18、ack tea Definition and basic requirements 1 Scope and field of application This International Standard specifies the parts of a named plant that are suitable for making black tea for consumption as a beverage and the chemical requirements for black tea that are used to indicate that tea from that so
19、urce has been produced in accordance with good production practice. This International Standard also specifies the packing and marking requirements for black tea in containers. This International Standard is not applicable to scented or decaffeinated black tea. 2 Normative references The following r
20、eferenced 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 1572, Tea Preparation of ground sample of known dry matter c
21、ontent ISO 1573, Tea Determination of loss in mass at 103 C ISO 1575, Tea Determination of total ash ISO 1576, Tea Determination of water-soluble ash and water-insoluble ash ISO 1577, Tea Determination of acid-insoluble ash ISO 1578, Tea Determination of alkalinity of water-soluble ash ISO 1839, Tea
22、 Sampling ISO 3103, Tea Preparation of liquor for use in sensory tests ISO 5498, Agricultural food products Determination of crude fibre content General method ISO 6078, Black tea Vocabulary ISO 9768, Tea Determination of water extract ISO 14502-1, Determination of substances characteristic of green
23、 and black tea Part 1: Content of total polyphenols in tea Colorimetric method using Folin-Ciocalteu reagent ISO 15598, Tea Determination of crude fibre content BS ISO 3720:2011ISO 3720:2011(E) 2 ISO 2011 All rights reserved3 Terms and definitions For the purposes of this document, the following ter
24、ms and definitions apply. 3.1 black tea tea derived solely and exclusively, and produced by acceptable processes, notably withering, leaf maceration, aeration and drying, from the tender shoots of varieties of the species Camellia sinensis (L.) O. Kuntze, known to be suitable for making tea for cons
25、umption as a beverage 4 Basic requirements 4.1 General requirements The tea shall have no taint and shall be reasonably free from extraneous matter. Liquor for assessment of taint shall be prepared by the method specified in ISO 3103. The assessment shall be described in the test report using terms
26、defined in ISO 6078. 4.2 Chemical requirements 4.2.1 The tea shall comply with the requirements specified in Table 1, in which all the figures given are expressed on the basis of the material oven dried at (103 2) C by the method specified in ISO 1573. 4.2.2 No limit is specified for the “moisture”
27、content of the tea as received. If desired, the actual loss in mass at 103 C of the sample as received may be determined and the result recorded in the test report. In such cases, the determination shall be carried out by the method specified in ISO 1573. Table 1 Chemical requirements for black tea
28、Characteristic Requirement Method of test Water extract, % mass fraction 32 min. ISO 9768 Total ash, % mass fraction 8 max. 4 min. ISO 1575 Water-soluble ash, % mass fraction of total ash 45 min. ISO 1576 Alkalinity of water-soluble ash (as KOH), % mass fraction 1,0amin. 3,0amax. ISO 1578 Acid-insol
29、uble ash, % mass fraction 1,0 max. ISO 1577 Crude fibre, % mass fraction 16,5 max. ISO 5498 or ISO 15598bTotal polyphenols, % mass fraction 9 min. ISO 14502-1 aWhen the alkalinity of water-soluble ash is expressed in terms of millimoles of KOH per 100 g of ground sample, the limits shall be: 17,8 mi
30、n.; 53,6 max. bThe specific method for the determination of crude fibre in tea is specified in ISO 15598, however for the purpose of routine estimation, the general method specified in ISO 5498 is adequate. In cases of dispute, the method of determination should always be that specified in ISO 15598
31、. The requirement of 16,5 % mass fraction remains unchanged regardless of the method used.5 Sampling See ISO 1839. BS ISO 3720:2011ISO 3720:2011(E) ISO 2011 All rights reserved 36 Methods of test 6.1 The samples of tea shall be tested for conformity with the chemical requirements of this Internation
32、al Standard by the methods of test specified in Table 1. 6.2 The requirements specified in Table 1, except for water extract, shall be determined using a ground sample prepared in accordance with ISO 1572. 7 Packing and marking 7.1 Packing The tea shall be packed in closed, clean and dry containers,
33、 made of material which does not affect the quality of the tea. 7.2 Marking The packages of tea shall be marked in accordance with any relevant legal requirements and agreements between the interested parties. BS ISO 3720:2011ISO 3720:2011(E) ICS 67.140.10 Price based on 3 pages ISO 2011 All rights
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