| Ready-to-drink green tea and Chrysanthemum Morifolium Ramat, beverage have been popular beverages due to their high level of polyphenols. However, the bottled ready-to-drink green tea and Chrysanthemum Morifolium Ramat, beverage are gradually becoming brown in color during shelf life. The oxidation of polyphenols was shown to be probable cause leading to the browning. So the present study was mainly focused on browning mechanism of ready-to-drink green tea and Chrysanthemum Morifolium Ramat, beverage, as well as the effects of anti-browning agents on those beverages during shelf life. Results as follows:1. In order to investigate the effect of different extraction methods on the quality of CM infusion for ready-to-drink CM production, experiment were designed with various experimental conditions, such as CM extraction (CME) temperature, CME time, liquid /solid ratio before CME. The solid extraction yield, color differences and the main flavones of luteolin and luteolin-7-O-β-D-glucoside were considered as quality identification. The best condition was the CME temperature 85~90°C, the CME time 30min and liquid/solid ratio 40:1. The main flavones of luteolin and luteolin-7-O-β-D-glucoside were analyzed by HPLC. The chromatographic condition was as follows: the HPLC system consisted of shimadze LC-2010A with a four pumps gradient system (shimadze Co.Ltd., Japan), a shimadze CLC-ODS column(6.0mm×150mm,5μm). The flow-rate of the mobile phase was lml/min. The column temperature was 28℃and sensitivity was 0.01aufs. The mobile phase composition used was: (A): acetonnitrile/acetic acid/water (6:1:193,v)); (B): acetonnitrile/acetic acid/water (60:1:139,v). The solvent composition started at 70% (v) solvent A and 30% (v) solvent B. The solvent B was by linear gradient during 45min until 100% (v) solvent B.2. The anti-browning technology usingβ-cyclodextrin and isoascorbic acid sodium salt was studied. Bothβ-cyclodextrin and Isoascorbic acid sodium salt can inhibit the oxidation of catachins.3. Browning of tea liquor is barrier to affecting shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea liquor were investigated. The levels of un-oxidized catechins such as epigallocatechin gallate (EGCg), epigallocatechin (EGC), epicatechin gallate (ECg), eipcatechin (EC) and total catechins in the tea liquor were significantly correlated to color parameters of the tea liquor. It was shown that both high temperature and illumination led to the browning of green tea liquor, and temperature was more important.4. It was shown that both high temperature and illumination led to the browning of CM liquor. The contents of total flavones, luteolin and luteolin-7-O-β-D-glucoside were undeelly decreased, which were significantly relative with CM liquor color differences. Unlike tea catechins in green tea liquor, illumination affects the liquor color and level of catechins greater than temperature.5. Anti-browning agents land 2 were used to control the browning of ready-to-drink green tea products, ready-to-drink CM products and ready-to-drink green tea & CM products, which were comparing with anti-browning agent 3 commonly used in beverage companies. The results showed that: All of the anti-browning agents had the same effects on ready-to-drink green tea products, ready-to-drink CM products and ready-to-drink green tea & CM products with and without sucrose. Anti-browning agents have negative effects on the liquor aroma, so some aroma additives can be used with anti-browning agents.
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