Background: Due to abundant and non-utilized resource of tea flowers (Camellia sinensis) world widely, many volatile compounds in tea flowers have been characterized. It is of interest to test the bioactivity of the natural essential oil of tea flowers.
Methods: Natural essential oil of tea flowers was prepared by using Supercritical Carbon dioxide Extraction (SFE). DPPH radical scavenging was used to evaluate the antioxidative activity of essential oil. All experiments were performed in triplicate and all data was expressed as a mean ± standard error of the mean. Comparisons among the means of various treatments were analyzed through Duncan’s test. One Way Analysis Of Variance (ANOVA) was used to determine the differences among means of treatments and the control.
Results: The optimum extraction conditions were the pressure of 30 MPa, temperature of 50°C, static time of 10 min, and dynamic time of 90 min. Based on GC-MS analysis, 59 compounds including alkanes (45.4%), esters (10.5%), ketones (7.1%), aldehydes (3.7%), terpenes (3.7%), acids (2.1%), alcohols (1.6%), ethers (1.3%), and others (10.3%) were identified in the essential oil of tea flowers. The essential oil of tea flowers showed relatively stronger DPPH radical scavenging activity than essential oils of geranium and peppermint, although it was weaker than those of essential oil of clove, ascorbic acid, tertiary butylhydroquinone, and butylated hydroxyanisole.
Conclusions: Essential oil of tea flowers extracted by SFE contained many kinds of volatile compounds and showed considerable DPPH scavenging activity.
Chen Xia, Youying Tu, Ziyin Yang, Yuxia Jin and Huilong Xia