The effect of grain size on the colour characteristics of durum semolinas

Horváth H., Zsuzsanna and Csató, Sándor: The effect of grain size on the colour characteristics of durum semolinas. Review of faculty of engineering : analecta technica Szegedinensia 2-3. pp. 96-103. (2010)

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Abstract

Pastas made of durum flour are becoming more prevalent also in our country , no eggs are needed for their preparation. The colour of the pasta produced this way is determined essentially by the colour of the durum semolina. Also in industrial practices instrumental colour analysis is applied for the colour qualification of durum semolina. In our work we examined how the grain size influences the colour characteristics and ash content of durum wheat grindings. The correspondence between the ash content and the colour characteristics was also analysed. Durum semolina from 12 different production units were used for our measurements. The semolina were produced from the yields of 2007 and 2008. The grindings were separated into different grainsize fractions by screening. The L*. a* . b* colour coordinates defined in the CIELab colour space were applied for the colour characterization. The measurements were carried out using a Hunter Miniscan colour analyser. The data was analysed applying variance analysis and regression analysis. On the basis of the obtained results we can establish that the grain size significantly influences (p<0.05) the L* lightness the a* redness and the b* yellowness coordinate as well as the variation of the YI yellowness index. When the grain size increases, the L* lightness coordinate decreases. The difference is the biggest between the means of the 0-160 nm and the 160 (im -250 nm fractions though even in the other cases the difference is at least 1 unit. Hence the bigger grains are darker. The a* redness coordinate, the b* yellowness coordinate and the YI yellowness index increases when the grain size increases. On the average the a* coordinate increases by 0.4 unit the b'coordinate by 3-4 units while the YI yellowness index by 5 units. Thus the colour of bigger grains is slightly redder and significantly yellower. The ash content decreases with the increase of the grain size. The mean ash content varied between 0.7-1.1%. The ash content of the whole grinding is equal to that of the 315 nm -500 nm fraction. The difference between the ash content of the subsequent grain size fractions is 0.1% on the average. Also the results have shown that there's a significant linear correlation between the ash content and each colour characteristic. (p<0.01).

Item Type: Article
Journal or Publication Title: Review of faculty of engineering : analecta technica Szegedinensia
Date: 2010
Number: 2-3
Page Range: pp. 96-103
ISSN: 1788-6392
Language: angol
Uncontrolled Keywords: Mérnöki tudományok, Kémia
Additional Information: Bibliogr.: 103. p. ; összefoglalás angol nyelven
Date Deposited: 2016. Oct. 15. 12:24
Last Modified: 2019. Jan. 07. 09:22
URI: http://acta.bibl.u-szeged.hu/id/eprint/11839

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