Green extraction technique of Cowpea protein: An optimization using response surface methodology

Protein extraction using the alkaline extraction method (alkaline soluble and acid precipitation) is a well-established technology that increases protein yields. Ultrasound-assisted extraction (UAE) is a relatively environmentally friendly method that enhances the quality of protein production. This study optimizes protein yields that depend on various extraction times, temperatures, and pH levels. Experiment design is often employed in conjunction with response surface methodology (RSM), particularly in the context of central composite design (CCD). The highest protein yield (61.40%) was obtained at an extraction time of 18 minutes, pH 9.5, and a temperature of 38°C. According to the ANOVA test, the independent variables in both linear and quadratic forms have an R2 value of 0.9589 and a 95% probability value (P < 0.05). The Pareto chart indicates that the independent variables, expressed in both linear and quadratic forms, have a significant impact on the response. The crucial values were 39.5°C, 19 minutes of extraction time, and a pH of 9.8. This study suggests that it can identify the optimal factors for achieving high protein yield extraction on an industrial scale and for food applications.