The Improvement Of Flavor And Safety Of Concentrated Green Tea Infusion By Enzymatic

With Zhejiang pan-fired as the main material,the sensory quality,safety and health of the high-quality concentrated green tea infusion after enzyme that tannin,protease, pesticide-degrading enzyme treatment had been mainly researched in this paper,and obtained the optimal parameter and the supporting technology,and to provide theoretical evidence for pilot scale test and practical production.The major results of this paper were as following:1. The appropriate amount of tannase can improve the mellow taste and the flavor of the tea infusion。The optimum parameters of the tannase acting on concentrated green tea infusion:the concentration of enzymatic degradation is 0.08u/ml, pH 4.0,40℃and 60 min.2. The umamizyme was more suitable than acid protease and papain in the tea reaction system, meanwhile, a better results of enzymolysis was obtained with perfect parameters which the concentration of enzymatic degradation is1000u/ml, pH 5.0,50℃and 180 min.3. Cellulase and pectinase enzyme have some synergistic reaction on flavor enzymes hydrolysising green tea concentrate. After adding 100u/g of cellulase, pectinase and flavor enzymes in tea infusion, the solid part of tea infusion increased from 2.5% to 3.0%, while amino acids increased to 1179mg/L, compared with using flavor enzymes, it increased some under the same conditions, tea flavor is greatly improved as well, so the effect of using complex enzyme hydrolysis is better than using the single enzyme;4. Pesticide-degrading enzyme has obvious effects on the degradation of organophosphorus pesticide residues of the green tea concentrate, the majority of the rate of degradation of organophosphorus pesticide residues in tea infusion is more than 80%, but had less effect on degradation rate of isocarbophos in the tea.5. According to the experimental results, during the tea extraction, adding the tannase, flavor, pectinase and cellulose with some certain proportion can improve product yields, and can significantly improve the flavor of green tea concentration, but adding Pesticide-degrading enzyme went nowhere on the flavor of green tea concentration; the optimal dosage of various enzymes in the green tea concentration:tannase 0.08u/ml, umamizyme 1000u/ml, cellulase 100u/ml, pectinase 100u/ml, pesticide-degrading enzyme 35u/ml; the optimal reaction time 180min; optimal process steps:extraction (The ratio of tea and water 1:12, extraction temperature 80℃)→added organophosphorus pesticide-degrading enzyme→extracted 30min→immediately cooled to about 45℃→enzyme solution,→added and extracted 180min→centrifuge filter→concentrated to 25-30%→sterilization→filling.