Optimization of extraction conditions by response surface methodology for preparing partially defatted peanut

Suitability of different solvents like acetone, benzene, chloroform, hexane and petroleum ether was compared on the basis of oil recovery from splited peanut. Response surface methodology (RSM) was used to optimize the factors like seed to solvent ratio and extraction time based on maximum oil recovery and high sensory scores. A rotatable central composite design was used to develop models for the responses. The results showed that hexane was best suited for oil extraction from peanut considering its highest value of extraction constant (k=6.60 x 10^-3 min^-1) with rapid, efficient and maximum extraction of oil than other solvents. Oil recovery found was linearly affected with seed to solvent ratio and time of extraction which was significant at P≤ 0.01 with a correlation coefficient (R²) of 90%. Variation in the surface appearance, color and overall acceptability were found significant with respect to seed to solvent ratio and time of extraction at second order regression model. The optimum values for seed to solvent ratio and extraction time were found to be 1:6 and 5 hr respectively with an overall acceptability of 8.31 and oil recovery of 9.03%.