Aroma characterization and antioxidant activity of supercritical carbon dioxide extracts from Terminalia catappa leaves

摘要

The green, yellow fallen, and red fallen leaves of Terminalia catappa were extracted using supercritical carbon dioxide at 2000. 3000 or 4000 psi and 40℃. The volatile components of the extracts were identified using gas chromatographic retention indices, mass spectra, and authentic compounds. Gas chromatography/olfactometry (GC/O) was employed for the analysis of aroma characteristics. Antioxidant activities of the extracts were also determined. A total of 18 compounds were identified in the leaf extracts. Among them, three highest amounts of compounds were ethyl acetate, 6,10,14-trimethyl-2-pentadecanone and phytol. Although (E,E)-2,4-decadienal with oily odour was not high in content, it was odour significant due to its odour value of 18,572-31,714. β-Ionone with the highest odour value of 82,857-44,5715 was described as a fruity, floral aroma. With respect to the antioxidant activity by the l,3-diethyl-2-thiobarbituric acid method, the extracts from yellow fallen and red fallen leaves exhibited higher inhibition of peroxidation than those from green leaves. Supercritical carbon dioxide extraction at 2000 psi and 40℃ resulted in the extracts with better antioxidant activity whereas lower inhibition of peroxidation was observed with the extracts prepared from the extraction at 4000 psi and 40℃.