Influence of ultrasonic treatment parameters on extraction yield of limonin from Wenling Gaocheng peels analysed by HPLC-UV

Abstract

Ultrasound-assisted extraction (UAE) is a promising technique for isolating bioactive compounds from plant materials, as ultrasound disrupts cell walls through mechanical effects, and facilitates the release of cellular constituents. Despite its growing popularity, the efficiency of UAE for extracting limonin from citrus peels, particularly Wenling Gaocheng, remains understudied. In the present work, we systematically explored the influence of various operational parameters on the yield of limonin using UAE. The limonin content was quantified using a Waters 2695 HPLC system coupled with a Waters 2487 UV detector. The effects of six parameters on the UAE of limonin from Wenling Gaocheng peels was examined through single-factor experiments. We observed that the limonin yield first increased and then decreased with decreasing particle size. The yield also increased as the solvent/material ratio increased, but the rate of increase decreased. Among the tested solvent concentrations, 70% ethanol was found to be the most effective. The yield significantly improved with increasing ultrasonic intensity up to 0.2556 W/cm2 before decreasing sharply. Between 20 and 70°C, the yield fluctuated slightly, and a gradual improvement was observed with longer extraction times. These findings provided valuable insights for future commercialisation of UAE to extract limonin from citrus peels.