Composition, functionalities, and digestibility of proteins from high protein and normal pea ( Pisum sativum ) genotypes

Abstract Although a lot of research has been focused on the applications of pea protein, the effects of genotypes on protein applications have not been sufficiently investigated. Three high protein genotypes and four normal genotypes were included in this study. The results showed that the pea proteins from these seven genotypes differed widely in 11S/7S ratio. P1141 and Lacombe had the highest 11S/7S ratio while P1142, P0540, and Cooper had the lowest. Since the three high protein genotypes were selected from different parent lines, they had different 11S/7S ratios, which may partially explain their various functionalities. This demonstrated the potential of using breeding as a tool to manipulate the 11S/7S ratio of pea protein. The 11S/7S ratio may play a more important role in determining the protein functionalities than high/normal protein level in the seed. The solubilities of all seven samples were pH dependent. At pH 7, Lacombe and P1141 had the lowest solubility among all the tested samples, which may be a result of their high 11S/7S ratio. The proteins from all genotypes showed comparative water and oil holding capacities. P1141, Lacombe and Earlystar showed excellent emulsifying and foaming capacity at all tested pHs, which may be attributed to their relatively higher 11S/7S ratio. The in vitro digestibility varied among genotypes regardless of high protein or normal genotypes but all higher than 75%. The results of this study demonstrated that breeding could manipulate the pea protein content and composition, which further determined its functional properties and applications in food products.