A fermented tea with high levels of gallic acid processed by anaerobic solid-state fermentation. (September 2016)

• Record Type: Journal Article
• Authors: Huang, Youyi; Xiao, Xiudan; Cong, Liu; Wu, Mengyao; Huang, Yingjie; Yao, Yanni
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 71(2016)
• Page Start: 260
• Page End: 267
• Publication Date: 2016-09
• Subjects: Pickled tea -- Anaerobic solid-state fermentation -- Gallic acid -- Fermentation metabolites -- Quality characteristics; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2016.03.047
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: Microbial tea products are widely welcomed for their unique quality characteristics. However, the quality characteristics of pickled tea, a microbial tea product traditionally consumed in most Asian countries remain unclear. Therefore, the quality characteristics of pickled tea processed using Camellia sinensis leaves through anaerobic solid-state fermentation were analyzed. During 60-d fermentation, the free amino acids, caffeine, and tea polyphenols in pickled tea kept much stable, the soluble sugar content showed significant and continuous decrease, but the water extract showed a continuously increasing trend. The optimal fermentation time for pickled tea was 30 d, at which its normal quality characteristics were formed: the sensory quality was the best, most free amino acids evidently increased, a high level of gallic acid was produced up to 25.7 g/kg, and volatile compounds were mainly alkanes such as heptadecane and hexadecane. It is the first report that high levels of gallic acid in a microbe-fermented tea processed by anaerobic fermentation reached to that levels in Galla chinensis, which will benefit development of a functional tea with high levels of active components and understanding the microbial transformation of tea components through anaerobic fermentation. Highlights: A high level of gallic acid in a fermented tea was produced up to 25.7 g/kg, similar to that in Galla chinensis. Thirty-day is the optimal fermentation time for the sensory quality of pickled tea. Most free amino acids in tea evidently increased through anaerobic solid-state fermentation.