Colour characteristics of winter wheat grits of different grain size

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Abstract

Nowadays, wheat has spread all over the world due to its extensive usability. The colour of wheat grits is very important for the milling and baking industry because it determines the colour of the products made from it. The instrumental colour measuring is used, first of all, for durum wheat. We investigated the relationship between colour characteristics and grain size in the case of different hard aestivum wheats. We determined the colour using the CIE (Commission Internationale de l’Eclairage) 1976 L*, a*, b* colour system measured by MINOLTA CR-300 tristimulus colorimeter. After screening the colour of the wheat fractions of different grain size, grits was measured wet and dry. We determined the L*, a*, b* colour co-ordinates and the whiteness index, too. To evaluate the values we had obtained, we used analysis of variance and regression analysis. We pointed out that the colour of wheat grits of different grain size is dependent on the hardness index of wheat. The lightness co-ordinate (L*) of grits of the harder wheat is smaller, while a* and b* co-ordinates are higher. We also found that while grain size rises, the L* co-ordinate decreases and a*, b* values increase in the case of every type of wheat. The colour of grits is determined by the colour of fractions of 250-400 μm in size, independently from the average grain size. The whiteness index and the L* colour co-ordinate have a linear relation (R2 = 0.9151); so, the determination of whiteness index is not necessary. The L* value right characterizes the whiteness of grits.

[1] J. Oliver, A. Blakeney, H. Allen, The colour of flour streams related to ash and pigment contents. Journal of Cereal Science, 17. 2. (1993) 169-182.

[2] J. Park, Instrumental colour formulation: a practical guide. North Carolina State University. (1993).

[3] M. Halászné-Fekete, P. Záhonyiné-Racs, Á. Keleti, Colour measurement of durum grits for aim of qualification in paste industry. Book of the XXVth Colouristic Symposium. (1995) 41-48.

[4] J. A. Rice, Mathematical statistics and data analysis. Duxbury Press. (1995)

[5] M. D’Egidio, M. Pagani, Effect of the different stages of durum wheat chain on pasta colour. Italian Food & Beverage Technology, 10. (1997) 17-20.

[6] A. Hotti, S. Sidhu, J. Al-Sager, Utillty of CIE tristimulus system in measuring the objective crumb colour of high-fibre toast bread formulation. Journal of Food Quality, 23. 1. (2000) 103-116.

[7] I. Konopka, W. Kozirok, D. Rotkiewicz, Lipids and carotenoids of wheat grain and flour and attempt of correlating them with digital image analysis of kernel surface and cross-sections. Food Research International, 37. 5. (2004) 429-438.

[8] J.M. Humphries. R. D. Graham, & D. J.Mares, Application of reflectance colour measurement to the estimation of carotene and lutein content in wheat and triticale. Journal of Cereal Science, 40. (2004) 151-159.

[9] V. Gökmen, H. Z. S,enyuva, Study of colour and acrylamide formation in coffee, wheat flour and potato chips during heating. Food Chemistry, 99. (2006) 238-243.

[10] Zs. László, Zs. Hovorka-Horváth, S. Beszédes, Sz. Kertész, E. Gyimes, C. Hod´ur, Comparison of the effects of ozone, UV and combined ozone/UV treatment on the colour and microbial counts of wheat flour. Ozone Science & Engineering Journal, 30. 6. (2008) 419-417.

Acta Universitatis Sapientiae, Alimentaria

The Journal of Sapientia Hungarian University of Transylvania

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