Molecular structure and functional properties of glycinin conjugated to κ-carrageenan and guar gum: A comparative study. (30th August 2022) - Zhang, Qing
Highlights: Glycosylation of glycinin with κ-carrageenan and guar gum was comparatively studied. K-carrageenan was more susceptible to glycinin glycosylation than guar gum. Both polysaccharides improved emulsifying properties of glycinin after glycosylation. Glycinin grafted with κ-carrageenan exhibited greater viscosity and viscoelasticity. Abstract: Molecular structure and functional properties of glycinin conjugated to κ-carrageenan and guar gum using a dry-heating method were comparatively analyzed. Glycosylation was confirmed by analyzing the degree of grafting, protein subunit composition, infrared absorption profile, and changes in contents of protein secondary structures. K-carrageenan was proven to possess a greater susceptibility to be grafted to glycinin than guar gum due to its relatively low molecular weight and negatively charged characteristics. The improvement of solubility by glycosylation with guar gum near the isoelectric point of glycinin was better than that by glycosylation with κ-carrageenan. Glycinin glycosylated with both polysaccharides exhibited enhanced emulsifying activity and stability. The enhanced apparent viscosity, elastic modulus, and viscous modulus also demonstrated that glycosylation promoted the appearance of stable elastic network structure. In summary, glycosylation with these two polysaccharides conferred glycinin superior emulsifying and rheological properties, and κ-carrageenan exhibited a better performance compared to guar gum.