Germination-induced nanoarchitectonic assembly of quinoa protein at neutral pH and its aerogels for microplastic...

Microplastics (MPs) have emerged as a growing concern due to their potential threats to human health and aquatic systems. Aerogels have shown promise for MP removal. However, low-cost, plant-derived aerogels remain underexplored. Plant proteins typically exhibit weak gelling capacity, limiting their utility in forming porous structures. Although acidic conditions (pH 2) have been used to induce protein fibrillation and enhance gelation, such methods are energy-intensive and environmentally unfavorable. In this study, we developed a sustainable and efficient strategy to induce quinoa protein fibrillation under neutral pH conditions via seed germination. Quinoa protein isolate (QPI) extracted from quinoa seeds germinated for 8 h formed fibrils (200-800 nm) upon thermal treatment at 95 °C for 30 min at pH 7. Germination improved the electronegativity of QPI to -30.6 mV, and reduced disulfide bonding via protein disulfide isomerase, promoting electrostatic repulsion and molecular unfolding to facilitate fibril formation. Inspired by germination, synergistic enzymatic strategy was discovered to induce 11S globulin fibrillation with enhanced fibrils' conversion rate of 42.7 % under neutral condition. The resulting fibril-based aerogels demonstrated efficient microplastic removal from both water and beverage systems, and their adsorption capacity reached 286.7 mg/g in coke, 457.5 mg/g in Sprite, and 370.9 mg/g in orange juice, highlighting their potential as low-cost, plant-based materials for microplastic removal.