Optimization of ultrasonic-assisted extraction model of Pinus koraiensis seed scales oil induced by tea saponin

Tea saponin was used for UAE of oil from Pinus koraiensis seed scales for the first time, and the extraction kinetic model was fitted and compared with that of traditional SE. Considering the relationship among the oil yield, proanthocyanidins content and solvent properties, ethanol was selected as the optimum extraction solvent. PBD and BBD were used to determine the optimal conditions: 63% aqueous ethanol solution, liquid-to-material ratio was 11:1 mL/g, ultrasonic power was 100 W, ultrasonic duration was 15 min, temperature was 45 °C, and the dose of tea saponin was 0.3%. Under the optimal conditions, the oil yield and proanthocyanidins content from P. koraiensis seed scales were 22.73 ± 0.42% and 3.04 mg/g ± 0.08%, respectively. The actual operating value was consistent with the theoretically predicted value. Comparison of the extraction kinetics model, oil components, physical and chemical properties, antioxidants, microstructure of oil residue, energy consumption and ecological emission characteristics of UAE and SE shows that UAE is a more advantageous technique.