335 Pasta brownness. A reappraisal of its basis and prediction in durum wheat breeding.

P. Feillet, C. Icard-Vernière, and J. C. AUTRAN. INRA, Unité de Technologie des Céréales et des Agropolymères, 2 Place Viala, 34060 Montpellier cedex 02, France.

In contrast to the yellow component of the color of pasta products, which has been well explained a long time ago, the brown (or grey) component of the color remains poorly-known and difficult to take into account in breeding. However, since the development of technologies of pasta drying using very high temperatures, brownness becomes more and more often a factor limiting in the use of European durum wheats. Previous studies had (i) suggested that the development of pasta brownness was the result of the activity of semolina peroxidases (PO), (ii) reported a clear-cut classification of old durum cultivars according to their PO composition, (iii) shown that PO groups corresponded to different levels of pasta brownness. However, recent comparisons of PO activity or PO isoenzymes with spaghetti, or pasta disc brownness from current varieties of European durum wheats did not confirm previous results: high PO activity does not always result in poor color. Because brownness level essentially pre-exists in the grain endosperm (semolina brownness is strongly correlated with that of the processed pasta – either fresh, or dried with either low or high temperature), new assumptions are discussed. Work is currently directed either towards investigation of PPO activity during grain maturation, PPO gradient between central endosperm and peripheral parts, and determination of brown pigments.