Experimental Study And Theory Forecast Of The Shelf-life Of Green Tea In Soft Pack

The shelf-life forecasting of the packing tea is always neglected in the domestic tea market. The incomplete system of the shelf-life forecasting seriously affects a series of questions of the tea exportation. In view of completing the theory and measure which forecast the shelf-life of the soft packed green tea,the experiments and the fundamental researches of its moisture absorption characteristic, the oxidized characteristic and the photosensitive characteristic are taken by the fries blue as the research object.The model of shelf-life of green tea in watervapour-proof packaging are established, and confirmed by the acceleration test.According to the adsorption theory and the experience model which the curve model the research obtains domestic and foreign, the equilibrium moisture content experiment is designed for fries blue. Many kinds of experiences model used to fits the tentative data, and the effect of the model fitting are synthesis appraisalled by using different kinds of ways, Finally the model of shelf-life of green tea in watervapour-proof packaging are established.In view of the oxidized characteristic of the principal constituent vitamin C and the tea polyphenol, the acceleration experiment is carried under the specific temperature and humidity, the model of the vitamin C oxidation speed is built by the isothermal method of the rmodynamics analysis theory.Finally the relation of temperature and the shelf-life of green tea are established.The factors which influence the principal constituents of the green tea are analysised, and the three factors orthogonals experiment of the temperature, the humidity, the illumination are carried on.The range analysis of the data is carried on.The result shows, the humidity is the most important factor which affect the chang of the colour, the temperature and the illumination have different effect in different moment.The shelf-life of the green tea in there kinds of soft plastic pack are forecast, and confirmed by the acceleration test. After thoroughly studies the relations of each kind of factor and the green tea,the better measure to extend and forecast the shelf-life is discussed.