HS-SPME/GC×GC-TOFMS 방법으로 가루 녹차의 금속 냄새 화합물 특정 분석

Abstract

Powdered green tea has a bright green color through shading cultivation. Moreover, people can intake all the active ingredients contained in the tea by directly drinking whisking powdered green tea instead of brewed tea water. This tea is loved by consumers worldwide under the name of “Green Tea Latte.“ Countries that produce powdered green tea compete fiercely for research and development to improve the color, flavor, aroma, and fine particles. This study analyzed the metallic odor compounds in the sensory evaluations of two powdered green teas using headspace-solid phase microextraction (HS-SPME)/ two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC-TOFMS) methods. Alk-1-en-3-ols, alka-1,5-dien-3-ols, alk-1-en-3-ones, alka-1,5-dien-3-ones, (Z)- and (E)-alka-1,5-dien-3-ols, and corresponding ketones are the metallic odors identified in previous research. GC-TOFMS (1D) and GC×GC-TOFMS (2D) were conducted for qualitative analysis. The results of 2D qualitative analysis identified four compounds (1,5-hexadien-3-ol, 1-octen-3-one, 1-octen-3-ol, and benzophenone) in a sample with metallic odor and three compounds (1-octen-3-one, 1-octen-3-ol, and benzophenone) in the normal sample. A calculation of the peak areas showed that the amounts of compounds were more than three times higher in the metallic odor sample than in the normal sample with areas of 9×107 and 3×107 , respectively. Thus, 1,5-hexadien-3-ol, which was the most obvious difference between the two samples, may cause the metallic odor.