Study of Bioactive Components and Color Properties of Dark Tea Infusion Manufactured by &lt;em&gt;Eurotium cristatum&lt;/em&gt; Using Submerged Fermentation

Pengxiang Yue,Xueling Gao,Yuwan Wang,Hengqian Lu

doi:10.19026/ajfst.10.2189

Abstract

The use of green tea infusion as culture broth for production of Dark Tea Infusion (DTI) with <em>Eurotium cristatum</em> was investigated. Fermentation process of produced DTI was monitored for 120 h, bioactive components and color properties were studied. After 120 h of fermentation, the levels of caffeine and flavonoids increased while contents of tea polyphenols, free amino acids and carbohydrates decreased. Thearubigins (TRs) and Theabrownin (TB) were the representative component in DTI, which increased in amount during Submerged Fermentation (SF). Turbidity of cultured broths decreased while lightness increased. The cultured broths formed the typical dark tea color characteristics of “redness” and “maroon” after SF and color properties were obviously improved.

Highlights

Fu-brick tea is a kind of unique dark tea with brick form compressed from the older, coarse and rough leaves band small branches of Camellia sinensis, mainly distributed in Hunan, Sichuan, Shaanxi and Yunnan provinces in China (Zhang et al, 2013)
Tea polyphenols analysis: Fermentation is the most important procedure for forming the special flavor of dark tea which derived from polyphenols by oxidation
It influences the contents of major catechins in teas

Summary

INTRODUCTION

Fu-brick tea is a kind of unique dark tea with brick form compressed from the older, coarse and rough leaves band small branches of Camellia sinensis, mainly distributed in Hunan, Sichuan, Shaanxi and Yunnan provinces in China (Zhang et al, 2013). Studies showed that, corresponded with stimulation of enzymes, E. cristatum fermentation can result in changes of catechins, free amino acids, proteins and polysaccharides (Wu et al, 2010; Zhang et al, 2014). These changes formed the unique color, aroma and taste of Fu-brick tea (Xu et al, 2007), and endow Fu-brick tea varieties of beneficial health effects, including antioxidant (Cheng et al, 2015), antibacterial (Keller et al, 2013), anti-obesity and hypolipidemic (Li et al, 2013; Fu et al, 2011). The changes of bioactive components and color properties of cultured broths were investigated

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSION