Multi-response optimization of oil extraction from pine nut (Pinus pinea L.) by response surface methodology: Extraction efficiency, physicochemical properties and antioxidant activity

Abstract

Effects of solvent extraction conditions on the extraction efficiency, physicochemical properties and antioxidant activity of pine nut oil were investigated and optimized by using three level Box-Behnken design (BBD). Temperature (25-65 degrees C), time (10-60 min) and solvent/sample (S/S) ratio (5-20 mL g(-1)) were chosen as the independent variables while the dependent variables were extraction efficiency, yellowness index (YI), peroxide value (PV), p-anisidine value (p-AnV), totox value (TV), DPPH-hydrophilic fraction (DPPH-HF), DPPH-lipophilic fraction (DPPH-LF) and DPPH-oil to obtain pine nut oil with high oil yield, and desirable physicochemical properties and antioxidant activity. N-hexane was found to be the most effective solvent for the extraction. Extraction efficiency, physicochemical properties and antioxidant activity of pine nut oil were highly affected by temperature, time and S/S ratio. Desirability function approach was used to determine optimum conditions. The optimum conditions for the production of pine nut oil with solvent extraction were attained at the extraction temperature of 39.3 degrees C, extraction time of 33.4 min and S/S ratio of 10.8:1 (mL g(-1)). At optimum conditions, the predicted values for the extraction efficiency, YI, PV, p-Any, TV, DPPH-HF, DPPH-LF and DPPH-oil yielded 80.03%, 59.89, 1.05 meq peroxide kg(-1) oil, 0.92, 3.02, 8.60%, 65.07% and 73.35%, respectively.