Factors Affecting the Colour of Durum Wheat Products

Institute of Cryobiology and Food Technologies, BG-1407 Sofia, Bulgaria


PETROVA, I., 2004. Factors affecting the colour of durum wheat products. Bulg. J. Agric. Sci., 333-340

The importance of genetic, environmental and technological factors for durum wheat pasta coloring is discussed. The pasta colour is a function of both intrinsic colour properties of durum wheat cultivars and colour loss during wheat processing. The genetic factors include the content of natural carotenoid pigments and their oxidative degradation during pasta manufacturing. Durum colour potential can be strongly affected by grain-damage due to weather, fungal infections, surface discoloration, sprouting, frost, heat-damaged kernels, immaturity that result in duller and browner pasta products. Numerous technological agents contribute to wheat colour change. The extreme increase of semolina yield and the improper semolina refinement lead to increased ash content, higher oxidative enzyme activity, higher pigment loss and more intense brown color of pasta products. Similarly, unsuitable mixing-extruding and drying conditions can exert a significant impact on colour quality of the end products. The knowledge of colour-related agents gives opportunities for colour management by development of durum wheat cultivars with high colour potential, and use of more rational and well-controlled grain processing. The most relevant testing technologies for colour measuring and control are described.

Key words: durum wheat, pasta, colour quality, factors, testing methods
Abbreviations: LOX - lipoxygenase; PO - peroxidase; PPO - polyphenol oxidase; CGC - Canadian Grain Commission; NIRS - near-infrared spectroscopy; V-NIRS - visible-near infrared spectroscopy