Effect of the molecular weight of a neutral polysaccharide on soy protein gelation. (December 2017)

• Record Type: Journal Article
• Authors: Monteiro, Sónia R.; Lopes-da-Silva, José A.
• Is Part Of: Food research international. Volume 102(2017)
• Page Start: 14
• Page End: 24
• Publication Date: 2017-12
• Subjects: Soy proteins -- Locust bean gum -- Molecular weight -- Protein-polysaccharide interactions -- Rheology -- Microstructure; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2017.09.066
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The effects of galactomannans with different molecular weights on the heat–induced gelation characteristics of soybean protein were investigated using dynamic small-strain rheometry, under conditions where the proteins carry a net negative charge (pH 7). Microstructure of the resulting gels was investigated by confocal laser scanning microscopy. Phase-separated systems were obtained with different morphologies and degree of phase separation, depending on both biopolymer concentrations and polysaccharide molecular weight. In general, a gelling enhancing effect on soy proteins was verified, despite extensive phase-separation processes observed at the higher polysaccharide molecular weight. This effect was demonstrated by an increase of the gelation rate, a decrease in the temperature at the onset of gelation, and an increase of gel stiffness and elastic character, with the length of polysaccharide chains. Overall, the results obtained established that the judicious selection of the galactomannan molecular weight may be used to modify the structure and gelation properties of soy proteins, originating a diversity of rheological characteristics and microstructures that will impact on the design of novel food formulations. Graphical abstract: Highlights: Enhanced gelation of soy proteins due to the presence of galactomannans. Gelation temperature decreases as the polysaccharide molecular weight increases. Gelation rate increases as the polysaccharide molecular weight increases. Gel stiffness increases as the polysaccharide molecular weight increases. Variety of phase separated microstructures by changing polysaccharide molecular weight.