Study of the impact of puroindolines, polar lipids and their association with gluten proteins and/or starch on wheat hardness.

Kernel hardness of (hard and soft) Triticum aestivum and T. durum wheats varies with the cultivar. It determines the milling behavior, the properties of the obtained wheat endosperm tissues (flour or semolina, both of which consist of starch granules embedded in a gluten protein matrix), their applications, and the texture of the resultant products. Rather than the starch granules or gluten proteins themselves, their interaction determines wheat kernel hardness. Major differences in endosperm hardness are attributable to the presence, absence or sequence polymorphism of the puroindoline proteins, which, when present, weaken the starch-protein interaction. In addition, the polar lipid level at the starch surface is negatively correlated with wheat kernel hardness. However, the mechanism behind the differences in wheat kernel hardness remains to be unraveled. In this project, puroindolines will be purified from soft wheat. Their association, and that of the different polar lipid classes, with and at the surface of the starch granules will be studied. A fractionation-reconstitution approach will be used to further elucidate the association of the different polar lipid classes, puroindolines, starch granules and/or gluten proteins. Finally, the role of polar lipids and puroindolines in a cereal based product will be studied.

Keywords:Wheat hardness, Cereal based product, Puroindolines, Polar lipids, Texture, Gluten proteins

Disciplines:Food sciences and (bio)technology, Biochemistry and metabolism, Systems biology, Medical biochemistry and metabolism, Other chemical sciences, Nutrition and dietetics, Agricultural animal production