Influence of temperature, time and alkali concentration on protein extraction from muskmelon seed meal

ABSTRACT This study was conducted to optimise the protein extraction process from defatted muskmelon (Cucumismelo) seed meal using response surface methodology. The defatted seeds had a crude protein content of 57.45 g/100 g and the whole seeds had a crude protein content of 18.75 g/100 g of dry solids. The extraction conditions were investigated for maximum protein yield from the seed meal. A Box–Behnken design was employed using three independent variables as temperature (40°C, 50°C and 60°C), time (5, 15 and 25 min) and alkali (NaOH) concentration (0.03, 0.09 and 0.15 g/l) to study the response variable (protein yield) by maintaining a solvent to meal ratio of 50:1 v/w. The experimental values of protein yield were found to be in the range of 70.31–77.31%. The coefficient of determination was found to be 0.89. Optimum protein extraction was obtained with 0.11 g/l alkali concentration, 22 min extraction time and a temperature of 40°C. Maximum protein yield (77.31%) was obtained at 0.09 g/L NaOH concentration, 40 oC temperature and 25 min extraction time. There was no significant effect on protein yield with the increase in temperature, while protein recovery increased with the increase in extraction time. The predicted value of protein yield was 76.59% and the experimental protein yield was 70.71%. GRAPHICAL ABSTRACT