Optimization of process parameters for degossypolisation of de-oiled cottonseed cake by response surface methodology (RSM)

The goal of this research is optimizing the process variables for removal of toxic compound gossypol from cotton seed meal by employing microwave pretreatment. A Box-Behnken Design (BBD) of response surface methodology (RSM) was employed, considering three process variables: moisture content for pretreatment (24–28 %), microwave power (300–900 W), and microwave time (2–6 min). This resulted in 17 experimental runs to evaluate the free gossypol, total gossypol, and protein content. The numerical optimization resulted in the best combination of process variables for the set of response properties included 26 % moisture content, 900 W microwave power level, and 6 min microwave time. Under the optimized conditions, the experimental values of free gossypol, total gossypol and protein content were found to be 0.047 %, 1.15 %, and 52.54 %, respectively. These values are closely related with the predicted values (free gossypol = 0.05 %, total gossypol = 1.19 % and protein content = 51.67 %) which indicates the models appropriateness. In comparison to traditionally extracted cottonseed meal, the improved microwave aided treatment reduced extraction time and solvent use. This investigation may help to reduce the amount of gossypol present in cottonseed meal, which would facilitate the utilization of cottonseed protein as a sustainable protein source in the future.