Optimization of Microwave-Assisted Extraction of Ursolic Acid in Residues of Eriobotrta Japonica

The optimum process of extracting ursolic acid from Eriobotrya japonica residues by microwave-assisted extraction (MAE) was studied. The optimum extraction process was optimized with orthogonal test. Experiments were made by using L9(34) orthogonal design with extractive yield of ursolic acid as index, investigating the influence of grinding degree, MAE power, MAE time, and the ratio of solid to liquid. Optimum extraction conditions were determined as follows: 95% ethanol, MAE 350 W, extraction time 190s, ratio of solid to liquid 1:10 (g:mL), extracting for three times. The yield of ursolic acid acid was 0.89%. The MAE method has higher yield, shorter extraction time and higher purity compared to Soxhlet extraction method.