BS-ISO-16305-2005.pdf

BRITISH STANDARD BS ISO 16305:2005 Butter Determination of firmness ICS 67.100.20 ? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 16305:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 23 February 2005 © BSI 23 February 2005 ISBN 0 580 45550 5 National foreword This British Standard reproduces verbatim ISO 16305:2005 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee AW/5, Milk and milk products, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible 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. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, 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. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference numbers ISO 16305:2005(E) IDF 187:2005(E) © OSI DI dnaF 5002 INTERNATIONAL STANDARD ISO 16305 IDF 187 First edition 2005-02-01 Butter Determination of firmness Beurre Détermination de la fermeté BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) DPlcsid Fremia ihTs PDF file may ctnoian emdebt dedyfepcaes. 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ISO cirypothg fofice Intetanrilano iaDrtaredeF yino saCe tsopale 65 eneG 1121-HC 02 avDimanat Buildi gn BoulA draveugust 08 sreyeR e B-1 030Brssuels leT. 14 + 20 947 2111 eTl. 23 + 29 337 888 aFx0 947 22 14 + 974 aFx0 337 2 23 + 431 -Email copyrightisoo.rg -Emailni off-lidif.org We bwww.is.o groWe bwww.fil-idf.o gr Plbuisdehi n Switlrez dna ii © ISO dnaID 5002 FA ll rihgtsser edevr BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) I ©SO dna ID 5002 F All irhgts seredevr iii Contents Page Forewordiv 1 Scope1 2 Terms and definitions.1 3 Principle.1 4 Apparatus.1 5 Sampling2 6 Storage of test samples2 7 Checking the cutting wire 2 8 Procedure.3 8.1 Preparation of test portion.3 8.2 Temperature equilibration of the test portions3 8.3 Temperature control during the measurements3 8.4 Determination3 9 Calculation and expression of results3 9.1 Calculation.3 9.2 Expression of results3 10 Precision4 10.1 Interlaboratory test .4 10.2 Repeatability4 10.3 Reproducibility4 11 Test report4 Annex A (normative) Apparatus5 Annex B (informative) Results of interlaboratory trial9 Bibliography .10 BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) iv I ©SO dna ID 5002 F All irhgts seredevr Foreword 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 subject 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 (IEC) 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 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 document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 16305IDF 187 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF), in collaboration with AOAC International. It is being published jointly by ISO and IDF and separately by AOAC International. BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) I ©SO dna ID 5002 F All irhgts seredevr v Foreword IDF (the International Dairy Federation) is a worldwide federation of the dairy sector with a National Committee in every member country. Every National Committee has the right to be represented on the IDF Standing Committees carrying out the technical work. IDF collaborates with ISO and AOAC International in the development of standard methods of analysis and sampling for milk and milk products. Draft International Standards adopted by the Action Teams and Standing Committees are circulated to the National Committees for voting. Publication as an International Standard requires approval by at least 50 % of the National Committees casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 16305IDF 187 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF), in collaboration with AOAC International. It is being published jointly by ISO and IDF and separately by AOAC International. All work was carried out by the Joint ISO/IDF/AOAC Action Team, Physical properties and rheological tests, of the Standing Committee on Minor components and characterization of physical properties, under the aegis of its project leader, Mr G.J. Beutick (NL). BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI blank 5002:50361 OSI SB Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI NITERNATNOIAL STANDARD IS:50361 O5002(E) ID:781 F002(5)E I ©SO dna ID 5002 F All irhgts seredevr 1 Butter Determination of firmness 1 Scope This International Standard specifies a method for the determination of the firmness of butter. The method is also applicable to butter prepared by recombination of milk components, aeration of butter and butter to which vegetable fat, spices or other foods have been added. Any changes with regard to the preparation of the butter, however, will influence its firmness characteristics. Therefore for the purposes of this International Standard, these products are not included. NOTE The firmness of butter as determined by this method is correlated with the spreadability of butter as determined by a test panel (see Reference 4). 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 firmness of butter force needed to cut through a sample cube of butter using a wire in accordance with the procedure specified in this International Standard NOTE The firmness of butter is expressed in newtons (N). 3 Principle A butter sample, at a strictly specified temperature, is cut vertically through using a defined horizontal cutting wire that moves downwards at a constant speed. The cutting force is measured in newtons by a force-measuring instrument. 4 Apparatus Usual laboratory apparatus and, in particular, the following. 4.1 Incubator, capable of operating at 10 °C ± 1 °C. 4.2 Water bath, capable of operating at 10 °C ± 0,1 °C. 4.3 Sample holder, with dimensions as given in Figure A.1, of accurate measuring size of 25 mm ± 0,2 mm, fitted with a (replaceable) handle (see Figure A.2) or a U-shaped handle (see Figure A.3). 4.4 Probe, of metal, with a cutting wire stretched tight for the measurement (see Figure A.4). The cutting wire shall be made of stainless steel, and shall be round with diameter of 0,3 mm ± 0,01 mm. 4.5 Measuring apparatus (e.g. texture analyser), capable moving the probe vertically downwards at a constant speed of 1,0 mm/s and parallel to one edge of the test cube. BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) 2 I ©SO dna ID 5002 F All irhgts seredevr It shall be capable of measuring the force over an appropriate measuring range. It shall be connected to a computer for continuous measuring of the force with an error of less than 0,05 N at 2 N and of at least 20 data points per second, placed in a cooling chamber or cooling device (4.7). Note that heat produced by the measuring apparatus may effect the firmness measurements if no appropriate measures are taken. 4.6 Sample preparation tool (e.g. a clip), with limbs of length approximately 70 mm, comprising a stretched tight wire, made of stainless steel, of maximum diameter 0,5 mm and length of about 100 mm, or a stopping knife with a blade not thicker than 0,5 mm. 4.7 Cooling device, for example that shown in Figure A.5. 5 Sampling A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage. Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 707. Test samples taken directly after production usually have a temperature above 10 °C and shall be cooled to or below that temperature. The temperature during transportation shall be kept at or below 10 °C. 6 Storage of test samples Store test samples taken directly after production for (official) control purposes in an incubator (4.1) at 10 °C ± 0,1 °C for (10 ± 1) days. If it is necessary to delay or interrupt this storage time, cool the test samples to a temperature of between 0 °C and 4 °C for up to 4 days, or by freeze them to a temperature of below 20 °C for a longer period. NOTE 1 The setting of butter is still evolving after its production and is strongly related to the storage temperature: the higher the temperature, the faster the setting. When stored at 10 °C, it can take up to 30 days before the setting stabilizes, while after 10 days about 80 % of the final firmness has already been reached. The butter setting is slow at a temperature of between 0 °C and 4 °C. Under these conditions no difference in the firmness of butter can be measured for up to 4 days after production. The setting stops completely when the butter samples are frozen. The time of storage at 10 °C ± 1 °C for test samples with another or unknown storage history (storage temperature/time combination) shall be agreed upon by the parties concerned. The conditions agreed upon shall be noted in the test report. NOTE 2 For example, this might be the case when the firmness of a test sample derived from consumer packages is to be measured. 7 Checking the cutting wire Check the length of the cutting wire regularly as it might stretch out as a result of intensive use, which also might affect the precisely specified diameter of the cutting wire. Check the wire length by using one of the following techniques. a) Hang a weight of 200 g in the middle of the cutting wire. Measure the deviation of the wire from its original position by using an appropriate measuring instrument. b) Set the measuring apparatus (4.5) to a cut-off force of 2 N. Let the apparatus measure the deviation in the central position of the metal clip as it is pushed against a round metal rod with diameter of approximately 0,5 cm. In both cases, the deviation of the central position shall not exceed 1 mm for a cutting wire with a length of 5 cm. BS ISO 16305:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:40:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:50361 O5002(E) ID:781 F5002(E) I ©SO dna ID 5002 F All irhgts seredevr 3 8 Procedure 8.1 Preparation of test portion Immediately before putting the test portions in the water bath, cut, without any delay, two test portions from the (incubated) test sample (Clause 6) by means of the sample holder (4.3). Carefully press the used sample holder (4.3) into the test sample until it is completely filled up with the test portion. Cut off that part of the test portion that runs out of the sample holder with the sample preparation tool (4.6) in accordance with the instructions for the used sample holder (see Annex A). Prevent any deformation of the test portion in the sample holder during its preparation