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1、DD CEN/TS 15465:2008 ICS 67.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW DRAFT FOR DEVELOPMENT Cereals and cereal products Durum wheat (T. durum Desf.) General guidelines for instrumental methods measurement of semolina colour Licensed Copy: London South Bank University
2、, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 3 2008 BSI 2008 ISBN 978 0 580 56620 2 Amendments/corrigenda issued since publication DateComments DD CEN/TS 15465:2008
3、 National foreword This Draft for Development is the UK implementation of CEN/TS 15465:2008. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional b
4、asis, so that information and experience of its practical application can be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an international standard. A revi
5、ew of this publication will be initiated not later than 3 years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. Accordin
6、g to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI
7、Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participation in its preparation was entrusted to Technical Committee AW/4, Cereals and pulses. A list of organizations represented on this committee can be obtained on request to its secretary. This public
8、ation does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. 0 September Licensed Copy: London South Bank University, South Bank University, 16/11/200
9、8 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 15465 August 2008 ICS 67.060 English Version Cereals and cereal products - Durum wheat (T. durum Desf.) - General guidelines for instrumental methods measurement of
10、 semolina colour Crales et produits craliers - Bl dur (T. durum Desf.) - Lignes directrices pour la mesure de la couleur des semoules par des mthodes instrumentales Getreide und Getreideerzeugnisse - Hartweizen (T.durum Desf.) - Allgemeine Leitlinien fr die Messung der Griefarbe mit instrumentellen
11、Verfahren This Technical Specification (CEN/TS) was approved by CEN on 28 January 2008 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question w
12、hether the CEN/TS can be converted into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in
13、force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ire
14、land, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassar
15、t, 36 B-1050 Brussels 2008 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 15465:2008: E Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/T
16、S 15465:2008 (E) 2 Contents Page Foreword3 Introduction.4 1 Scope 5 2 Terms and definitions .5 3 Apparatus .5 3.1 General5 3.2 Spectrocolorimeters6 3.3 Colorimeters.6 4 Procedure for sample preparation.6 4.1 General6 4.1.1 Introduction6 4.1.2 Dry semolina 6 4.1.3 Wet semolina6 5 Measurements6 5.1 Ge
17、neral6 5.2 Dry semolina 7 5.3 Wet semolina7 6 Test report7 Bibliography8 Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/TS 15465:2008 (E) 3 Foreword This document (CEN/TS 15465:2008) has been prepared by Techn
18、ical Committee CEN/TC 338 “Cereals and cereal products”, the secretariat of which is held by AFNOR. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. A
19、ccording to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Ita
20、ly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/T
21、S 15465:2008 (E) 4 Introduction The colour measurement of a milled product like semolina is an important characteristic for its end use; it is the ability of a durum wheat or a semolina to give a coloured final product. The indirect measurement of potential colour of semolina by chemical determinati
22、on of carotenoid pigments (see EN ISO 11052) is not the same colour perceived by the human eye. The instrumental measure of yellow index and lightness allows to obtain a better evaluation of colour. Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Co
23、py, (c) BSI DD CEN/TS 15465:2008 CEN/TS 15465:2008 (E) 5 1 Scope This standard defines general guidelines for the instruments used to determine colorimetric characteristics of semolina samples in the dry or wet form. 2 Terms and definitions 2.1 colour of semolina result of measurement performed by u
24、sing a spectrocolorimeter or colorimeter in the conditions indicated in this European Standard 2.2 colour space expression of the colour of an object or of a light source by some parameters expressed by figures NOTE Among the different systems, two are considered here: a) the tri-stimulus values x,
25、y, z: which are at basis of existing colour space of CIE (Commission Internationale de lEclairage - International Commission on Illumination). These values reproduce the theory of colour perception by the human eye based on three components. b) the colour space CIELAB (1976) : this system is the mos
26、t used for measuring the colour of objects. L* indicates the lightness and extend from 0 (black) to 100 (white); a* and b* are chromaticity indexes, respectively: - +a* towards red and a* towards green; - +b* towards yellow and b* towards blue/ 2.3 illuminants light source characterized by a spectra
27、l curve, whose energy relative distribution is defined in the field of wavelengths which are able to influence the object colour vision NOTE The illuminants normalized by the CIE 1, are the following: a) Illuminant A: representing the light emitted by the integral radiator at the absolute temperatur
28、e of 2856 K (approximately); b) Illuminant B: representing the direct light of sun of a proximal colour temperature similar to 4874 K; c) Illuminant C: representing a medium day-light with a proximal colour temperature similar to 6774 K; d) Illuminant D65: representing one of the relative spectral d
29、istribution of the day-light energy which corresponds to a proximal colour temperature similar to 6504 K; It is recommended for obtaining the results to select colour space CIE LAB and illuminant D65. 3 Apparatus 3.1 General There are two different types of instruments: spectrocolorimeters and filte
30、r colorimeters. NOTE The word “colorimeter” is also a generic appellation which can be applied to any colour measuring instrument based on any principle. Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/TS 15465
31、:2008 (E) 6 3.2 Spectrocolorimeters Spectrocolorimeters enable the measuring of the luminance spectral factor, of reflection or transmission, and the determination of the colorimetric characteristics. They provide, in function of wavelength, the properties of reflection or transmission of considered
32、 materials. A dispersive device position related to the sample defines two lighting ways: - lighting by monochromatic light (monochromator placed between source and sample); - lighting by polychromatic light (monochromator placed between sample and detector). 3.3 Colorimeters The filter colorimeters
33、, as indicated by the name, use some appropriate filters, generally three, whose spectral transmission band covers a great part of the visible domain. These filters are determined by the manufacturer to obtain a measuring result corresponding to that which should be obtained if the object was lighte
34、d by the light source specified. 4 Procedure for sample preparation 4.1 General 4.1.1 Introduction Colorimetric measurements are very sensitive to semolina granulometry and to the instrument used. The preparation protocol shall be clearly defined and controlled. 4.1.2 Dry semolina Before the analysi
35、s, the samples shall be homogenised. The measure may be made either on semolina as received or on a defined fraction of the semolina. In this last case, by sieving adequately the sample, a better homogeneity for a defined semolina sample can be obtained, reducing the variability of particle size ran
36、ge. 4.1.3 Wet semolina With the aim of reducing the interferences on the colour measures due to the normal particle size distribution of semolina, it is possible to wet the semolina to obtain a sheet of fresh pasta and to perform colour measures on the surface of this sheet. 5 Measurements 5.1 Gener
37、al Before every measures series, the apparatus shall be calibrated. The colorimeter calibration shall be made through opaque stable materials (as ceramics, glaze, ) sampled and supplied by manufacturers. When the colorimeter is used, a further calibration for better measure accuracy can be performed
38、 using references next to the colour of samples to be measured. Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/TS 15465:2008 (E) 7 5.2 Dry semolina The semolina sample shall be posed in a container with a plan
39、e surface, optically neutral, equal or greater than the measurement surface of the instrument. The measure will be performed on this plane surface against which the semolina is posed, and to avoid any parasite light source, a black opaque screen shall cover both the sample-holder and the measure win
40、dow of instrument. Sample-holders for the measure of granular material are provided as attachment by apparatus manufacturers. 5.3 Wet semolina The pasta obtained from wet semolina will be posed directly in front of the measure window of instrument on a black background. To avoid the dehydration of s
41、urface sample, the time between the pasta preparation and the colour measurement should be limited as much as possible (it should not exceed 60 s). 6 Test report The test report (colorimetric characteristics of a sample) shall contain the following information. a) apparatus : trade-mark, type, diame
42、ter of opening of measure window; b) sample : for dry semolina: milling process, particle size, conditions used for obtaining sample; for wet semolina: conditions used for obtaining pasta, hydration rate of the fresh pasta, time elapsed between pasta making and measure; c) general conditions of meas
43、urements: illuminant used (illuminant D65 is recommended), type of references used for calibration, room temperature; d) values obtained : colorimetric system ( L*, a*, b*); number of measures and relative standard deviation. The test report shall include all information necessary for a complete des
44、cription of the sample and the measurement details which could affect the final result. Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 CEN/TS 15465:2008 (E) 8 Bibliography 1 CIE 15:2004, Colorimetry, 3rd Edition 2
45、 EN ISO 11052:2006, Durum wheat flour and semolina - Determination of yellow pigment content (ISO 11052:1994) Licensed Copy: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 This page has been intentionally left blank Licensed Cop
46、y: London South Bank University, South Bank University, 16/11/2008 12:36, Uncontrolled Copy, (c) BSI DD CEN/TS 15465:2008 BSI Group Headquarters 389 Chiswick High Road, London, W4 4AL, UK Tel +44 (0)20 8996 9001 Fax +44 (0)20 8996 7001 standards BSI - British Standards Institution BSI is the indepe
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