Clarification Measures And Mechanisms For Pineapple Juice And Tea Beverage

In this paper, the clarification effects of chiotsan and xanthan gum on pineapple juice and green tea were studied. Response surface model and the orthogonal test were used to optimize the clarification process. Haze–style experiments were performed to decide the main haze-active materials in pineapple juice and green tea beverage. The sediments of pineapple juice and tea beverage and the components of the clarified beverage were analyzed.Through the analysis for single variance, the levels of every variance in response surface model evaluation based on the turbidity for pianpple juice clarification, were finally confirmed as follows: chiotsan:xanthan gum:1.3:0.7-1.5:0.5, temperature: 40-50℃, time:50-60min. After process optimization, the optimized conditions for clarification were as follows: chiotsan:xanthan gum:1.3:0.7, temperature: 50℃, time:56min, the lowest turbidity reached 1.68±0.10NTU.The ratio of chiotsan to xanthan gum, time and pH were selected as indexes according to orthogonal design L9(34). After process optimization, the optimized conditions for tea beverage clarification were as follows: chiotsan:xanthan gum:9:1, pH:4.1, time:65min, the lowest turbidity reached 0.93±0.01NTU.Both pineapple juice and green tea beverage hazes belonged to the type of protein-tannin haze. The addition of chitosan/xanthan gum clarified both the beverages by changing the contents of haze-active substances. In pineapple juice, protein was found decreased by 61.47%, amino acid decreased by 58.11%, total polyphenols decreased by 13.19%, tannin decreased by 59.28% and pectin decreased by 49.99%. In green tea beverage, tea polyphenols was found decreased by 26.99%, catechin decreased by 56.02%, protein decreased by 73.43%, acid amino decreased by 34.047% and caffeine decreased by 19.92%。Haze-active substances analysis indicated that protein was most attributed to the pineapple juice haze and polyphenols to the tea beverage. Caffeine was not involved in the the formation of the sediment. Beverage could be effectively clarified by changing the proportions of its haze-active substances with chitosan/xanthan gum.