Effect of the extraction process parameters on aquafaba composition and foaming properties

The cooking water from chickpeas, also called aquafaba, is generally discarded as waste. Aquafaba contains a pool of different organic compounds with excellent techno-functional properties. This study aims to investigate how the different extraction conditions affect the yield, composition, and foaming properties of aquafaba using response surface methodology (RSM). The effect of temperature (60, 80, and 100 ℃), chickpea to cooking water ratio (1:1, 1:1.6, 1:4), and heating time (90, 165, 240 min) was investigated. In particular, the protein profiles of aquafaba were analyzed by SDS-PAGE and Fourier Transform Infrared spectrometry (FTIR), while freeze-dried aquafaba was inspected with differential scanning calorimetry (DSC) and its foaming properties were explored by visual analysis. We observed that the processing temperature affects the glass transition (T_g), denaturation temperature (T_d), and melting temperature (T_m). Regarding protein secondary structures, no visible peaks at the Amide I region were detected by FTIR for the lower processing temperature, time, and chickpea-to-water ratio, indicating that in these conditions, protein extraction and unfolding was not completed. Besides, the extraction temperature affects the foaming capacity (FC) with the highest value observed at 80 ℃, the CWR ratio of 1:1.6, and a time of 165 min. Foam stability (FS) presents a similar trend in all extraction conditions.