The role of the 7S/11S globulin ratio in the gelling properties of mixed β-lactoglobulin/pea proteins systems

Abstract

Using a combination of pea protein isolates (PPI) and β-lactoglobulin (βlg) presents an interesting approach to improve the gelling properties of PPI compared to the use of PPI alone. While controlling the 7S/11S ratio has proven effective in improving the gelling properties of PPI, more complex models need to be studied. Specifically, the effects of diverse 7S/11S ratios and the inclusion of βlg and 2S albumin on gel formation remain unexplored. Therefore, this study aimed to 1) determine the optimal 7S/11S ratios and 2) identify the interactions involved in the formation of model βlg—pea protein gels generated from globulin and albumin-enriched fractions. Results revealed that pea protein gels with a 7S/11S ratio of ∼ 1.89 achieved the highest firmness (131 Pa). Gelation was primarily driven by hydrophobic interactions (∼ 41%) involving 7S vicilin and 2S albumin, while most of the 11S legumin did not contribute to the protein gel. Conversely, a 7S/11S ratio of ≤ 1 facilitated the formation of the firmest gels (300–657 Pa) in the presence of βlg. These gels were primarily formed via disulfide bonds (36–65%) with βlg, 11S legumin, and 2S albumin as the main proteins involved, while 7S vicilin gelled independently through hydrophobic interactions. Based on these results, we propose a mechanism illustrating the interactions in mixed βlg—pea protein gels. This study provides new insights into how 7S/11S ratios, gel firmness, and protein interactions interplay during the gelation of mixed βlg–pea protein systems, paving the way for innovation in developing a new food category.