Changes of Total Fatty Acid Contents during Manufacture of Green Tea

Abstract

The samples used in this experiment were fresh tea leaves (S-1), grean tea (S-2), green tea prepared by heating at 130°C for 30min (S-3), corresponding to refired green tea, and green tea prepared by heating at 170°C for 30min (S-4), corresponding to roasted green tea, i.e. Hoji-cha. Crude lipids (CL) were extracted with CHCl3-MeOH (2:1), and then separated into three fractions, which were chloroform fraction (CH), acetone fraction (AC) and methanol fraction (ME), by a silicic acid column chromatography using three kinds of solvent systcms. Total fatty acid contents of CL of S-1, S-2, S-3 and S-4 were 4.0, 3.3, 2.8 and 3.0%, respectively. Fatty acid contents of all fractions showed a tendency to decrease during manufacture of green tea, and the degree of decrease in ME was slightly large compared to other fractions. In AC, the ratio of main unsaturated fatty acid (C_18:2, C_18:3) to main saturated fatty acid (C_16:0) of S-4 was a little smaller than those of other samples, but there was little difference in the ratios among other fractions.