Abstract:Green tea infusion sediments mainly contain polyphenols. The combination of phenolic substances, caffeine, proteins and other large molecules will cause the phenomenon of tea solution after cold muddy. Sediment in green tea infusion will not only affect the appearance of the product, but also damage the taste and aroma quality of the infusion. The main substances that bind to caffeine and proteins are the ester catechins EGCG and ECG, and the ester catechins have more galloyl and hydroxyl groups, which tend to form precipitates compared with the non-ester catechins. In this study, tannase was added to the clarification step of tea infusion to improve the taste and reduce the phenomenon of after-cooling turbidity, and the optimal process of tannase to reduce the precipitation rate of green tea infusion was concluded by combining a one-way experiment with an orthogonal experiment. The best process to optimize the green tea infusion was under the temperature of 30 ℃, the addition of tannase was 0.15%, and the enzymatic hydrolysis was carried out for 60 minutes, The obtained green tea enzymatic solution had light bitterness and astringency, high degree of sweetness and low sedimentation.In conclusion, the tea infusion with added tannase has better taste. This study explores the process of tannase to optimize the quality of green tea extract, which provides a new idea for high quality green tea extract products and market demand.
