Process optimisation of microwave-assisted extraction of peony ( Paeonia suffruticosa Andr .) seed oil using hexane-ethanol mixture and its characterisation
Ethanol and hexane mixture agent microwave-assisted extraction (MAE) method was conducted to extract peony (Paeonia suffruticosa Andr.) seed oil (PSO). The aim of the study was to optimise the extraction for both yield and energy consumption in mixture agent MAE. The highest oil yield (34.49%) and lowest unit energy consumption (14 125.4 J g -1) were obtained under optimum extraction condition: solid-liquid ratio 0.37 g mL -1, extraction time 3.72 min, extraction temperature 80.92 °C, ethanol ratio 20.00%. GC–MS results showed that unsaturated fatty acids (UFAs) accounted for 88.60% of total fatty acids in PSO. Moreover, linolenic acid content of 37.35% was the highest UFA and caused PSO to possess good nutrition. PSO in DPPH radical scavenging experiment showed that IC50 value of 28.80 ± 2.13 mg mL -1 exhibited strong antioxidant property. All experiments proved that mixed solvent MAE is an efficient and promising method to extract PSO. This method can effectively reduce the energy consumption and extraction time.