Comparison of the Odor Concentrates by SDE and Adsorptive Column Method from Green Tea Infusion

Abstract

The odor concentrates from green tea prepared by a simultaneous distillation and extraction (SDE) under reduced pressure and an adsorptive column method were investigated. A total of 218 compounds were quantified and identified by GC and GC-MS. Total concentrations were 92.9 ppm by SDE and 11.9 ppm by the column method. The concentrations of aliphatic alcohols and aldehydes were 7409 and 2681 ppb in the SDE concentrate and 241 and 108 ppb in the column concentrate, respectively. The concentrations of terpene alcohols were 8399 and 807 ppb, respectively. Most of ketones were found several times in the SDE concentrate compared with the column one. Further, large quantities of 1-propen-2-yl formate, pentyl formate and (Z)-3-hexenyl butanoate were formed during SDE, while 3-hexenyl hexanoate decreased. Coumaran, coumarin, vanillin, furanones, and lactones disappeared, while aromatic aldehydes, ionone derivatives, and indole were formed in quantity during SDE operation. SDE caused serious formations and decompositions of volatile compounds in green tea infusion, but the column method gave the odor concentrate with natural green tea flavor.