Presentation Information
[P02-177]The Characteristic Aromas in Black Tea Shochu and their formation factors
○JIAFENG LI1, Yumiko Yoshizaki1,2, Haiyan Zhu3, Taiki Futagami1,2, Hisanori Tamaki1,2, Kazunori Takamine1,2 (1. The United Graduate School of Agricultural Sciences, Kagoshima University (Japan), 2. Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University (Japan), 3. Hunan Agricultural University (China))
Keywords:
black tea shochu,aroma formation,OAV,GC–MS,timing of addition,tea liquor,tea residue
Black tea is an important product in China and has a distinctive floral and fruity aroma formed during processing. While, shochu is a traditional Japanese spirits made from various main materials with koji. Koji is a solid-state culture cultivated with koji mold on the steamed rice. It contains large amounts of enzymes produced by koji mold. In shochu making, the β-glucosidase contained in koji contributes to the release of volatile compounds from precursors during fermentation. These compounds are further transformed by yeast during fermentation and heat during distillation, contributing to the rich flavor of shochu derived from main materials. Therefore, black tea is expects to be an attractive main material for shochu making. This study aimed to clarify the characteristic flavor, the key compounds, and production factors of black tea shochu.
Black tea shochu was prepared with different addition timings and tea forms following a conventional shochu making process. The black tea used was produced in Yibin, Sichuan Province, China. Day1 shochu (tea leaves added on the first day of fermentation), B1H shochu (tea leaves added 1 h before distillation), tea-extract shochu (the extracted tea added on day 1), tea-residue shochu (spent tea leaves added on day 1). A control shochu without tea was also prepared.
Fermentation progressed faster in Day1, tea-extract, and tea-residue moromi (fermented mash) than in the control. It indicated that tea affected alcoholic fermentation and yeast proliferation. Sensory evaluation showed that Day1 and tea-extract shochu had stronger fruity and floral notes and a milder taste, whereas B1H and tea-residue shochu exhibited stronger tea-like and grassy notes, a fuller taste, and slight pungency. GC–MS and OAV analyses indicated that decanal and trans-2-nonenal contributed to the grassy aroma. While, ethyl 2-hexenoate, an ester with a tropical fruity note, was higher in Day1 and tea-extract shochu. It was presumed to be formed from water-soluble glycosidic precursors during fermentation. In contrast, the floral aroma compounds linalool and β-damascenone were higher in the B1H shochu. It suggested that the addition just before distillation of tea better retains the original tea aroma. β-Ionone and β-cyclocitral, which contribute floral and green aroma notes, were higher in Day1, B1H, and tea-residue shochu. It indicated that the these compounds released or generated from lipophilic precursors in tea during distillation.
In conclusion, the addition of black tea addition improved the fermentation efficiency of moromi, and both the timing of black tea addition and the form of the tea material markedly influenced aroma formation and sensory quality in black tea shochu, resulting in distinct flavor profiles. These findings indicate the potential of black tea as a raw material for shochu production.
Black tea shochu was prepared with different addition timings and tea forms following a conventional shochu making process. The black tea used was produced in Yibin, Sichuan Province, China. Day1 shochu (tea leaves added on the first day of fermentation), B1H shochu (tea leaves added 1 h before distillation), tea-extract shochu (the extracted tea added on day 1), tea-residue shochu (spent tea leaves added on day 1). A control shochu without tea was also prepared.
Fermentation progressed faster in Day1, tea-extract, and tea-residue moromi (fermented mash) than in the control. It indicated that tea affected alcoholic fermentation and yeast proliferation. Sensory evaluation showed that Day1 and tea-extract shochu had stronger fruity and floral notes and a milder taste, whereas B1H and tea-residue shochu exhibited stronger tea-like and grassy notes, a fuller taste, and slight pungency. GC–MS and OAV analyses indicated that decanal and trans-2-nonenal contributed to the grassy aroma. While, ethyl 2-hexenoate, an ester with a tropical fruity note, was higher in Day1 and tea-extract shochu. It was presumed to be formed from water-soluble glycosidic precursors during fermentation. In contrast, the floral aroma compounds linalool and β-damascenone were higher in the B1H shochu. It suggested that the addition just before distillation of tea better retains the original tea aroma. β-Ionone and β-cyclocitral, which contribute floral and green aroma notes, were higher in Day1, B1H, and tea-residue shochu. It indicated that the these compounds released or generated from lipophilic precursors in tea during distillation.
In conclusion, the addition of black tea addition improved the fermentation efficiency of moromi, and both the timing of black tea addition and the form of the tea material markedly influenced aroma formation and sensory quality in black tea shochu, resulting in distinct flavor profiles. These findings indicate the potential of black tea as a raw material for shochu production.
Comment
To browse or post comments, you must log in.Log in