Extraction, characterization, and functional properties of ultra-low gossypol protein from cottonseed meal

Cottonseed protein (CSP) is unsuitable for human consumption due to its gossypol toxicity. The present study aimed to extract protein from cottonseed meal with ultra-low gossypol content and evaluate its functional properties for food products. The study developed a protein extraction process with gossypol removal treatment to unlock its potential to generate cottonseed meal protein isolate with ultra-low gossypol content.Key factors, including the pH of the extraction solvent time washing, and drying of protein pellets, were optimized to improve protein yield and reduce gossypol content. Extraction was performed using 0.15 M NaCl, 0.27% Na2SO3, and 0.1 M KOH at pH-12 for 2 hours at ambient temperature. The protein isolate yielded a recovery rate of 73.9%, with free and total gossypol concentrations of 348 ppm and 4170 ppm, respectively. The isolate demonstrated excellent functional properties, including a water holding capacity of 3.795 ± 0.987 ml/g, oil absorbing capacity of 2.069 ± 0.103 ml/g, foaming capacity of 500%, and stability of 88%.The present work lies in the successful extraction of a gossypol-free protein isolate with promising functional properties, making it suitable for preparing various value-added food products such as biscuits and cakes.