Ethanol-precipitated chickpea aquafaba: A potential foaming agent and emulsifier

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 and carbohydrate profile of AQE-P. Ethanol precipitation generated a precipitate with reduced simple sugar (sucrose, galactose, and arabinose) as well as oligosaccharides (stachyose, raffinose, and trehalose). 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 exhibited improved foaming properties due to its higher protein and polysaccharide content compared with freeze dried aquafaba. AQE-P lost its foamability when treated with alpha-amylase, while those hydrolyzed by glucoamylase maintained high foamability. 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.