Effect of extraction conditions on total phenolic content and antioxidant activity of Celastrus tonkinensis Pit stem extract

Abstract

Celastrus tonkinensis Pit. is an herb that has many uses in medicine and is good for health. However, current research on this plant is quite limited. In this study, dried stems were used as raw materials to extract phenolic compounds with the help of heated magnetic stirring. The dried stem slices were washed and dried at 60^oºC to a constant weight. The dry ingredients are ground finely and then sifted through a sieve to remove particles with sizes between 106 and 250 μm. Factors affecting the extraction process, such as solvent type, material-to-solvent ratio, extraction time and temperature, were investigated. The target functions are total polyphenol content (TPC) and antioxidant activities (DPPH, ABTS and FRAP). The results show that the best extraction conditions are when using 70% ethanol solvent, the ratio of raw materials to solvent is 1: 40, and the extraction time is 30 minutes at a temperature of 60°C. The total polyphenol content and antioxidant activities obtained under the above conditions were 5.088 μg GAE/mL (TPC), 36.195% (DPPH), 11.402% (ABTS) and 84.849 μg TE/mL (FRAP), respectively. The stems of Celastrus tonkinensis Pit. are a potential source of raw materials, rich in compounds with antioxidant activity. The extract can be concentrated into dry extracts, opening up the possibility of application in cosmetic and pharmaceutical products.