Enhancing Pea Protein Functionality through Glycation Following a Novel and Efficient Upcycling Approach

The interest in plant proteins is expanding with shifts in consumers' diets toward sustainable foods. While pea protein, a prominent plant protein contender, has acceptable nutritional quality, it generally has inferior functionality compared to soy protein, limiting its expanded utilization. Accordingly, effective measures to enhance pea protein functionality for successful incorporation in various applications should be investigated. Maillard-induced glycation is a modification technique that involves incubating the protein with reducing carbohydrates under controlled conditions. This work aims to develop a sustainable and scalable approach to produce pea protein with improved functionality and nutrition through the employment of a natural reaction and valorization of co-products. Pea protein was glycated with oligosaccharides from pea starch and fiber, which are co-products of pea protein production. Samples were incubated under controlled glycation conditions, which resulted in a limited and controlled glycation, with no propagation to advanced stages. After purification, glycated pea protein was subjected to structural, functional, and nutritional analysis. Hydrolysis of endogenous pea starch was optimized to produce maltodextrin with 76% of the chain length between 2-20 DP (DE: 14.6). Additionally, the hydrolysis of fiber was optimized to achieve 3 oligosaccharide fractions with different molecular weights, followed by membrane and chromatographic purification. After glycation and purification of pea protein and maltodextrin, a moderate blockage of amine groups (~30%) was achieved, with a relatively low surface hydrophobicity, markedly enhanced protein solubility (~90%) at pH 3.4, and a nonimpacted protein in-vitro digestibility (~100%). Similarly, after glycation of pea protein and polygalacturanan (3-10kDa, DE: 8.81), a moderate blockage of amine groups was achieved (24.4%). The current study investigated for the first time the upcycling of two pea co-products as sources to glycate pea protein for enhanced functionality. The uniqueness of this work emphasizes not only developing a successful modification process but also ensuring sustainability and scalability.