Characterization of light-induced aroma components in green tea beverages using aroma extract dilution analysis with gas chromatography–olfactometry

Abstract

Most green tea beverages are sold in transparent polyethylene terephthalate bottles and are displayed under lighting on the shelves in convenience stores and supermarkets. The exposure of green tea beverages to light sometimes results in off-flavors. The key aroma components contributing to the off-flavors of these beverages are unknown. We identified key aroma components contributing to the off-flavors induced by light exposure using aroma extract dilution analysis with gas chromatography–olfactometry. In addition, odor-active values of these components were calculated based on the threshold and quantitative values. Seven aroma-active components namely, 1-octen-3-one, (Z)-1,5-octadien-3-one, (E,E)-2,4-heptadienal, (E,Z)-2,6-nonadienal, 3-methylnonane-2,4-dione, (E,E)-2,4-decadienal, and trans-4,5-epoxy-(E)-2-decenal, were identified as the key aroma components contributing to the off-flavors induced by light exposure of green tea beverages. These seven components were lipid-derived aroma components, and we believe they are produced from linoleic and linolenic acids in green tea beverages upon exposure to light.