Selection of Ontario soybean varieties tailored for specific food processing functionality

This thesis focused on soybean varietal differences of the Harovinton variety and its eleven derived null-lines which could lead to the breeding of varieties tailored to produce specific functional ingredients. Soy protein gels with different subunit compositions and glycinin/beta-conglycinin ratio had distinctive gelation temperatures and resulted in gels with different network structures. The absence of A3 and the combination of A1, A2 and A4 subunits of glycinin enhanced the formation of heat-induced gels. The ratio glycinin/beta-conglycinin was not correlated to stiffness of soy protein gels. Changes in the protein composition of the soybean lines brought also changes in the composition of the carbohydrate fraction. Mixed systems containing gluten protein and soy protein from different sources and protein composition affected the gluten properties differently. It was concluded that there is a great potential to enhance the physical properties of soy protein by modulating the composition of the glycinin and beta-conglycinin subunits.