Composition and properties of ethanol-precipitated chickpea aquafaba

Increasing concerns among consumers regarding environmental sustainability, religion, health, and food safety have led to increasing prominence of plant-based food products. Aquafaba, a viscous liquid by-product obtained from canned or pressured-cooked chickpea, has gained popularity as a cost-effective egg replacement in gluten-free, vegan, and baked foods. In this study, we applied ethanol precipitation to aqueous chickpea aquafaba, yielding a white powder product (AQE-P). Proton nuclear magnetic resonance spectroscopy (1H NMR) analysis was employed to determine the molecular weight, carbohydrate profile and composition of foam produced from AQE-P. Results revealed significant variations in the chemical composition of aquafaba produced from different chickpea cultivars. Ethanol precipitation effectively reduced simple sugar (sucrose, galactose, and arabinose) as well as oligosaccharides (stachyose, raffinose, and trehalose) from aqueous aquafaba. AQE-P primarily consisted of water-soluble polysaccharides (24.8%, including soluble fiber and gelatinized soluble starch), protein (35.7%), oligosaccharides (18.4%) and insoluble fiber (21.2%). Notably, AQE-P extracted from both fresh and refrigerated aquafaba (4 °C, 24 h) exhibited improved foaming properties due to its higher protein and polysaccharide content. In conclusion, ethanol precipitation can be a simple, rapid, and feasible technology for chickpea aquafaba processing, yielding a functional powder ingredient, AQE-P. This product has potential as a plant-based emulsifier and foaming agent in various food applications, offering enhanced storage stability, nutritional value, and functionality when compared to aqueous or dried aquafaba.