Formation, construction, and functional properties of amyloid fibrils derived from chickpea protein isolate

Food protein-derived amyloid fibrils exhibit significant potential for applications in the food industry and biomaterials. Chickpea is a legume widely cultivated worldwide and rich in carbohydrates, fiber, essential minerals, and vitamins. Moreover, it serves as an inexpensive and abundant source of protein. This study investigated the alterations in the structural and functional properties of chickpea protein isolate (CPI) during fibrillation (pH 2.0, 85 °C, 0-12 h). An increase in Thioflavin T (ThT) fluorescence intensity (10.99-47.40) and a shift in microscopic morphology from irregular granules to a network of coiled fibrils indicated the formation of chickpea protein isolate amyloid fibrils (CPAF). During this process, proteins were progressively degraded into small peptide fragments, which reassembled into fibrils enriched with β-sheet structures. Meanwhile, changes in appearance and turbidity signified protein oxidation during heating and the occurrence of a partial Maillard reaction. An increase in protein flexibility from 0.32 to 0.39 indicated enhanced conformational flexibility, with hydrophobic interactions and hydrogen bonding playing a critical role in fibrillation. Notably, CPAF exhibited a substantially enhanced emulsifying activity index, increasing from 23.40 to 55.46 m²/g, and foaming capacity from 53.33 % to 130 %, compared to native CPI. The findings regarding the properties of amyloid fibrils may offer new strategies for the broader application of CPI in the food industry (p < 0.05).