Oil binding capacity and related physicochemical properties of commercial plant protein products

Providing sufficient food to a growing population while addressing the rise of food-related diseases requires innovative solutions. The use of plant proteins as structuring agents for oils has shown potential because of their healthier fatty acid profiles compared to solid fats. Thus, this study aims to investigate the potential correlations between the properties of proteins and their oil binding capacity (OBC) to provide insights into their applicability in structuring oil. Two samples each of sunflower, rapeseed, and soy protein products obtained from different manufacturers were denatured by heat and dispersed in oil after freeze-drying. Whey protein isolate (WPI) was used as a reference. The results indicate that, with some modifications, rapeseed and sunflower proteins can bind amounts of oil (3.7 oil [g]/protein [g]) comparable to that of WPI (4.04 oil [g]/protein [g]). However, the extraction process affects the final results and the texture of the protein-oil dispersion. Moreover, the protein solubility in NaCl, carbohydrate content, particle size, and the quantity of alpha-helical structures are positively correlated with the OBC, whereas an increase in the firmness of the dispersion is negatively associated with it. There was no correlation found between the changed beta-sheet structure resulting from the heat treatment and the OBC. This study emphasizes the ability of plant proteins to structure oil and explains how to evaluate the physical and structural properties of plant proteins. Technical insights that may lead to the production of more sustainable and healthier food products are provided.