Physicochemical properties of amyloid-like fibrils from ultrasonication-induced plum seed protein-catechin conjugates

Amyloid-like fibrils show promise as natural functional ingredients in the food industry owing to their distinctive structure and properties. However, the compact conformation of many plant proteins often limits the efficient production of functional amyloid-like fibrils. In this study, amyloid-like fibrils were fabricated from plum seed protein-catechin conjugates prepared via an ultrasonication-induced method. The fibrils were systematically characterized by microscopy and spectroscopy, and their emulsifying and rheological functionalities were evaluated. Compared with fibrils from native protein, ultrasonicated protein, and alkaline-induced conjugates, those derived from the ultrasonication-induced conjugates exhibited a more ordered structure, increased contour length and branching, and significantly enhanced surface hydrophobicity. These structural improvements translated into superior emulsifying performance and a unique heat-induced gelation ability. The results demonstrate that ultrasonication-induced covalent modification is an effective pretreatment strategy for enhancing both the formation and functional properties of plant protein-based amyloid-like fibrils.