Optimisation of the Extraction Process and Compositional Analysis of Lipase-inhibiting Components from Morus alba L. Leaves

In this study, on the basis of single factor experiments, the effects of raw material mass concentration, ethanol volume fraction, ultrasonic power, extraction temperature, and extraction time on the lipase inhibition activity of mulberry leaves extract were investigated in combination with response surface methodology to optimize the ultrasonic-assisted extraction process of the lipase-inhibiting components of mulberry leaves. Meanwhile, the active ingredients of mulberry leaves extract were analyzed by UPLC-Q-TOF HRMS. The results showed that the optimal extraction process parameters for the lipase-inhibiting components of mulberry leaves were as follows: The mass concentration of raw material was 0.05 g/mL, volume fraction of ethanol was 70%, ultrasonic power was 195 W, extraction temperature was 31 ℃ and the extraction time was 40 min. Under these conditions, the lipase inhibition rate of mulberry leaves extract was 39.68%. A total of 1067 compounds were identified. Flavonoids and phenolic acids accounted for the highest proportion, containing 203 and 201 compounds, respectively. These compounds might be the material basis for the lipase inhibiting activity of mulberry leaves extract. In this study, the ultrasonic-assisted extraction process of mulberry leaves was optimized to improve the extraction efficiency of the lipase-inhibiting active components, and the main active ingredients were analyzed. The results may provide a reference for the functional application of mulberry leaves in improving lipid metabolism and the development of health food.