Development Of Fermented Pu-erh Tea Wine

Pu-erh tea is a kind of after-fermentation tea which is of many kinds of health care functions, such as weight loss, reducing blood lipids, anti-microbes and anti-cancer, so the combination of both Pu-erh tea and wine will have good market prospects, especially the fermented Pu’er tea wine. In the study, Pu-erh tea wine was produced by Pu-erh tea and rice as main raw materials in semi-solid state fermentation which using Xiaoqu as the fermentation agent. This work was mainly focused on the sthdy technology of fermented Pu-erh tea wine. The clarifiers of Pu-erh tea wine were studied and its antioxidant activity was also studied.Theabrownin is one of the main pigment components and it is also an efficient composition in Pu-erh tea. The theabrownin in Pu-erh tea was determined by empirical method. The process was complex and it was not suitable for the determination of the theabrownin in Pu-erh tea wine. The concentration of alcohol and the pH value of wine may be effect on the stability of the theabrownin. Considering this, the effect of the concentration of alcohol and pH value on the measurement of the theabrownin in Pu-erh tea wine were studied in the experiment. The results were as follows:the theabrownin in the acidic environment of pH 2.0-7.0 and the low alcohol wine was stable. Meanwhile, a rapid and simple method for determination of theabrownine was estabilished.The pretreatment method and adding time of Pu-erh tea had a certain influence on tea wine fermentation. Therefore, three pretreatments to Pu-erh tea, such as no treatment, steam pretreatment and hot water extraction in the fermentation were studied. The tea adding time were studied, such as steaming, before saccharifying, after saccharifying and fermentation. The results showed that the steam pretreatment time 3 min and adding tea before saccharifying were conductived of Pu-erh tea wine fermentation. The single factor and orthogonal experiments were used to study the effect of rice/water ratio, the use level of Xiaoqu, tea/rice ratio and fermentation temperature on the Pu-erh tea wine. The results showed that the best technological condition was as follows:the rice/water ratio was 1:1, the use level of Xiaoqu was 2.00%, the tea/rice ratio was 4:100, and the fermentation temperature was 25℃. Under the fermentation condition, the alcohol content of the Pu-erh tea wine was 17.1%vol, the total acid content was 4.42 g/L, and the content of theabrownin was 2.12 g/L, the finished wine possed harmonious taste and the aroma of tea and liquor.The fermentation of the tea wine was turbied, so the further clarification experiment was necessary. Compared to natural clarification, five clarifiers including bentonite, diatomite, gelatin, casein and chitosan were applied in the clarifying treatment of Pu-erh tea wine. The transparency and the content of theabrownin were detected. The results showed that the diatomite was the best in the effect of clarificathion of Pu-erh tea wine. The adding of diatomite was 0.6 g/L, time was 24 h, the transparency could reach 96.0%, and the content of theabrownin was 1.57 g/L. After clarification, Pu-erh tea wine seemed to clear and transparent, lower loss of theabrownin.In the antioxidant experiments, the reduction capacity, DPPH-radical scavenging acticity and O2·-radical scavenging acticity of Pu-erh tea wine were studied. The results indiciated that when the additive volume of wine was 0.5 mL, the reduction capacity of the Pu-erh tea wine and the rice wine were 0.672 and 0.530, respectively. The scavenging rate on DPPH of the two kinds of rice wine were 94.81% and 72.90%, respectively. The scavenging rate on O2·-of the two kinds of rice wine were 43.10% and 37.40%, respectively. In the results showed above, Pu-erh tea wine exhibited strong DPPH-radical scavenging acticity and reducing capacity, and had a certain O2·-radical scavenging acticity. The results of experiments revealed that the addition of Pu-erh tea could enhance the antioxidant capabilities of rice wine in some respects.