Welcome to Journal of Tea Science,Today is

Journal of Tea Science ›› 2021, Vol. 41 ›› Issue (2): 213-227.doi: 10.13305/j.cnki.jts.20210315.002

• Research Paper • Previous Articles     Next Articles

Study on the Changes of Main Flavor Components of Yunnan Large Leaf Sun-dried Green Tea Before and After Fungal Fermentation

NING Jing1, LI Jianquan1, LIU Benying2,*, ZHENG Hongfa1, LU Fengmei3, CHEN Lei2, LIU Zhen1, YE Shengtao3, HUANG Hao1, YANG Peidi1, WU Gang2,4, YANG Yang1,*   

  1. 1.Tea Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China;
    2. Tea Research Institute, Yunnan Academy of Agricultural Sciences, Menghai 666201, China;
    3. Yunnan Defeng Tea Industry Co., Ltd., Mangshi 678400, China;
    4. Menghai Yuncha Technology Co., Ltd., Menghai 666201, China
  • Received:2020-11-24 Revised:2020-12-18 Online:2021-04-15 Published:2021-04-13

Abstract: Yunnan large leaf sun-dried green tea was used as raw material to make light pressed sun-dried green loose Fu tea, hand pressed and machine pressed sun-dried green Fu brick teas by natural fungal fermentation method. Through sensory evaluation and physical and chemical detection, the changes of sensory quality and main flavor components of sun-dried green tea before and after fungal fermentation were studied. The results show that: the bitter and astringent taste of the three fungal fermented sun-dried green teas was obviously weakened, and changed to mellow. The aroma changed from refreshing to aging and had a unique fungus fragrance. The liquor color changed from bright yellow green to bright orange, and the color of dry tea and infused leaves were obviously deepened. The contents of tea polyphenols, catechins, free amino acids, total flavonoids, soluble sugar etc. of the three fungal fermented sun-dried green teas decreased to varying degrees, especially the ester catechin decreased significantly with the decreasing rates of 56.91% (P<0.01), 31.80% (P<0.05) and 64.06% (P<0.01) respectively. The contents of caffeine and water extract increased slightly, while the contents of tea polysaccharide, gallic acid and anthocyanin increased significantly. The relative contents of linalool and its oxides with flower and wood aroma and methyl salicylate with medicinal aroma in the fungal fermented sun-dried green teas increased from 33.94% and 1.92% before fungal fermentation to 56.73%, 57.62%, 45.98% and 8.47%, 8.53% and 7.56% respectively. While the relative contents of other alcohols and most ketones with flower and fruit aroma and aldehydes with refreshing and green grass aroma decreased significantly. Among them, the relative contents of 1,2,3-trimethoxybenzene and 1,2,4-trimethoxybenzene with aging aroma increased significantly from 1.51% and 0.56% before fungal fermentation to 5.87% and 3.75% respectively in machine pressed sun-dried green Fu brick tea. Therefore, the refreshing aroma of sun-dried green tea decreased after fungal fermentation, showing the characteristics of aging aroma, and more obvious aging aroma was identified in the machine pressed sun-dried green Fu brick tea.

Key words: Yunnan large leaf sun-dried green tea, fungal fermentation, sensory quality, flavor components

CLC Number: