Techno-functional, physicochemical and thermal characteristics of black chickpeas aquafaba under ultrasound pre-processing

Aquafaba is the liquid that remains from the cooking of beans in the canning industry, generally discarded as wastewater. This research aimed to optimize ultrasound pretreatment to enhance this by-product and introduce it as a high-added value product (known as liquid gold) in the food industry. The results showed that with the increase in the sonication time and amplitude, the extraction efficiency, soluble protein content, the density, and dry matter content of black chickpeas aquafaba increased significantly (p < 0.05). The results also demonstrated that foaming ability (in short ultrasonication times) and foam stability significantly increased with higher amplitude. The results of numerical optimization showed that ultrasound pre-treatment for 30 min with an amplitude of 72 % on black chickpeas before the cooking process created the best conditions for aquafaba extraction. Under these optimized conditions, the results yielded the highest values so that extraction efficiency, protein content, density, dry matter, foaming ability, and foam stability were 212.07 %, 3546.7 mg/kg, 1.038 g/mL, 4.76 %, 243.57 %, and 44.50 % respectively. Thermogravimetric and FT-IR analysis showed that the pre-sonication process not only makes aquafaba thermally stable, but also does not cause any structural changes in its chemical components. According to the favorable physicochemical characteristics of aquafaba, this product can benefit the food industry. It can be a material with high added value, profitable for the canning industry.