Structural–Functional Characterization and Bioactive Potential of Alternative Grain Proteins: An In-Depth Comparison of Quinoa and Oat Proteins Isolates

The growing preference for plant-based proteins has led to increased interest in quinoa and oat as vital sources of plant-derived proteins. This study conducted a comprehensive characterization of two quinoa protein isolates (QJP1 and QJP3) and two oat protein isolates (OBP3 and OPP4). Results showed that quinoa protein, particularly QJP1, was found to be rich in lysine and, compared with oat protein isolates, exhibited potent antioxidant properties, making it an ideal choice for vegetarians, vegans, and the elderly who require plant-based sources of essential amino acids and antioxidants. On the other hand, oat proteins, especially OPP4, showed a higher digestibility rate and a variety of differentially expressed proteins with potential health benefits, suggesting they may be particularly beneficial for consumers seeking rapid nutrient absorption, such as athletes. The study also highlighted the presence of common proteins within different quinoa and oat cultivars, indicating a high degree of similarity in their protein compositions. However, the unique protein profiles of QJP3 and OBP3 suggests that they may be more suitable for elderly populations with specific health concerns, such as hypertension and immune function. The research underscores the complementary roles of quinoa and oats in addressing diverse dietary requirements within sustainable nutrition frameworks.