Physicochemical and antioxidative properties of ultrasound-assisted extraction of mahua (Madhuca longifolia) seed oil in comparison with conventional Soxhlet and mechanical extractions
R. C. N. Thilakarathna, Lee Fong Siow, Teck‐Kim Tang, Eng‐Seng Chan, Yee‐Ying Lee
Abstract
Ultrasound-assisted solvent extraction (UAE) was applied to extract underutilized Madhuca longifolia seed oil. The effect of extraction time, temperature, solvent type, solvent/sample ratio, and amplitude on the oil yield and recovery were investigated. Approximately 56.97% of oil yield and 99.54% of oil recovery were attained using mild conditions of 35 min, 35 °C, 40% amplitude, isopropanol to acetone (1:1), and solvent to sample (20 mL/g). UAE oil yield and recovery were comparable with Soxhlet extraction (SXE) whilst mechanical pressing (ME) yielded < 50% of UAE recovery. UAE does not affect the fatty acids composition (46% C18:1; 22% C16:0; 21% C18:0, 10% C18:2), and triacylglycerol profile (23% POO, 17% POS, 16% SOO, and 14% POP). Interestingly, UAE extracted oil conferred remarkably (P < 0.05) higher antioxidant capacity (IC50 of DPPH 106.60 mg/mL and ABTS 39.80 mg/mL) than SXE (IC50 of DPPH 810.40 mg/mL and ABTS 757.43 mg/mL) or ME (IC50 of DPPH 622.38 mg/mL and ABTS 392.87 mg/mL).