Effect of Aging Time on Quality of Lingtou Single-clump Teas

Effects of aging time on major quality indicators of the single-clump teas from Lingtou were determined. Two types of the teas, Lanhua and Milan aromatic varieties, were aged for 5, 10, 15, and 20 years prior to brewing for sensory evaluation. The results indicated that, as the aging time increased, (a) water extracts and pH of the teas declined; (b)contents of water and soluble sugars increased; (c) polyphenols increased on Milan tea, but reduced and then leveled off on Lanhua tea; (d) free amino acids content increased on Lanhua, and declined on Milan; (e) soluble protein decreased followed by an increase on Lanhua, while increased on Milan; (f)except polyphenols in control and pH after aging for 5 years, all quality indicators on teas of both varieties reached a significant level (P < 0.05); (g) aging particularly enhanced the accumulation of polyphenols, soluble sugars and soluble protein on Milan, and that of free amino acids, soluble protein and sugars on Lanhua; whereas, polyphenol content stayed relatively constant for both varieties throughout the aging process. Taking both chemical and sensory evaluations into consideration, it appeared that aging for 20 years for Lanhua and 15 years for Milan aromatic tea would allow them to reach their respective most desirable quality.