Amyloid-like aggregation of soy proteins: critical review on impacts in food nutrition, function, and sustainability

Soy proteins are widely used in plant-based foods but can form amyloid-like aggregates with cross-β structures during processing. While these aggregates may enhance functional properties such as gelation and emulsification, they could reduce protein digestibility and quality scores (e.g., DIAAS, PDCAAS), raising nutritional and health concerns. This review aims to critically evaluate the mechanisms driving aggregate formation, their nutritional and physiological implications, strategies to mitigate adverse effects, and roles in achieving sustainability. Intrinsic (e.g., protein type, conformation) and extrinsic (e.g., temperature, pH, ionic strength) factors influencing aggregation of major soy proteins, including glycinin and β-conglycinin, were examined with a focus on major soy products, including soy milk, tofu, tempeh, miso, natto, edamame, soy sauce, and soy flour. Analyzing emerging evidence suggests that the protein aggregates resist proteolysis and resemble amyloids associated with human proteinopathies; however, their physiological and nutritional implications remain underexplored. This work further assessed how processing conditions modulate aggregate formation and potential effects on gut health and systemic responses. The capability of mitigation strategies, including mild thermal processing, pH adjustment, salt control, and enzymatic treatment, to maintain protein quality while preserving functional attributes was also evaluated to elaborate on roles in food nutrition improvement. Through integrating structural, nutritional, and sustainability perspectives, this review identifies research gaps and proposes food processing strategies aligned with Sustainable Development Goals (SDGs) 2, 3, and 12.