Optimization of ultrasound-assisted extraction of pomegranate seed oil using response surface methodology and the composition analysis

Studies on the ultrasound-assisted extraction of pomegranate seed oil using pomegranate seeds as raw material are carried out.On the basis of single factor experiments,using the yield of pomegranate seed oil as the response,Box-Benhnken central composite design was applied to provide experimental data for establishing a regression model describing the extraction of pomegranate seed oil,and response surface were plotted for analyzing the pairwise interactive effects of solid-to-liquid ratio,ultrasonic extraction temperature,ultrasonic power and ultrasonic heating time on response.It is found that the optimum extraction parameters are as follows:the solid-liquid ratio is 1:12 g/mL,ultrasonic extraction temperature is 51 ℃,ultrasonic power is 70 W and ultrasonic heating time is 40 min.The maximum extraction yield of pomegranate seed oil was 18.75%.Moreover,fatty acid composition of pomegranate seed oil was analyzed by GC-MS.The results indicated that fatty acid was composed of punicic acid(64.73%),linoleic acid(9.68%),oleic acid(8.91%),palmitic acid(5.35%),stearic acid(4.36%),eicosatrienoic acid(2.57%),docosanoic acid(1.42%),tetracosanoic acid(0.61%) and tricosane acid(0.23%).