Studying The Effects Of Shan Tea Fusion And Sugarcane Juice Ratios And Types Yeast Culture On The The Quality Of The Fermented Mixture

Abstract

Shan tea (Camellia sinensis var. Shan) is the most valuable specialty of Vietnam owing to its remarkable benefits to human health. Fermentation of tea fusion e.g., Kombucha normally involves the addition of refined sugars that may not be healthy for consumers, and because it employs a natural fermentation process, thus, the quality of the product is inconsistent and the risk of getting toxin-producing contaminants is high. Thus, the objectives of this project were to assess the physicochemical and biological properties (reducing sugar content, antioxidant activity, total polyphenol content, alcohol concentration, and microbial density) of the fermented mixture with different ratios of Shan tea infusion and sugarcane juice (as a source of sugars) using ethanol producing Saccharomyces cerevisiae and aroma producing Wickerhamomyces anomalus. The obtained data from the co-culture found that at the end of the fermentation process, the treatments with higher tea infusion volume had lower sugars and alcohol contents, but higher polyphenols and better antioxidant activity. The treatment with 75% tea infusion and 25% sugarcane juice seemed to be the most suitable to produce the fermented beverage. The total polyphenols, ethanol, Brix, and reducing sugars of this fermented sample were 911.313GAE µg/ml, 4.917%, 1.677oBrix, and 2.059g/l respectively. This treatment also had a higher antioxidant property (IC50=39.566µl/ml). The 75% tea infusion and 25% sugarcane juice mixture was then fermented using a monoculture of S. cerevisiae. The obtained data showed no significant difference between the monoculture and co-culture in terms of Brix, reducing sugar, alcohol level, total polyphenol, and antioxidant properties. These indicated that S. cerevisiae would have been dominant in the co-culture. Overall, the mixture of 75% tea infusion and 25% sugarcane juice was the best option for fermented beverage production. There is no significant difference in physicochemical and biological properties between the monoculture and co-culture, however, the aroma of the fermented product was enhanced by the presence of W. anomalus, thus, the co-culture of S. cerevisiae and W. anomalus is recommended.