The Study On Variation Trend, Extraction, Purification And Oxidation Of Persimmon Polyphenol

Persimmon trees are one of the important economic species in Hunan Province which are widely planted. In this paper, based on the research of polyphenols' extraction and initial purification of the persimmon fruits, the growth process of fruit and the variation trend of polyphenol content in main persimmon variety were systematically studied, and antioxidant capacity of polyphenols of persimmon fruit and persimmon leaves were studied. The main contents and conclusions are listed as follows:1 Setting up the spectrophotometry analysis method to detect the content of persimmon fruit total polyphenol and condensed phenolics. Studied the extraction effect of ultrasound-assisted extraction to polyphenol of persimmon fruit. The polyphenols was completely extracted under the following extraction condition:90% ethanol concentration, material-liquid ratio 1:40, time 30min and extraction temperature 40℃. Comparison of horizontal and vertical to 13 persimmon varieties, the result showed that persimmon fruit polyphone content has been rising until June, then decrease, and polyphenol content of astringent persimmon varieties generally higher than sweet persimmon variety. So the early September is appropriate to pick persimmon fruit of local varieties as daily product raw material.2 In this study, macroporous resin was used to the preliminary purification of persimmon fruit polyphenol. Macroporous resin in accordance with the adsorption mechanism, the study of macroporous resin itself from the physical, chemical characteristics and the nature of the adsorption media to start using static adsorption and desorption experiments on the macroporous resin filter. Determined optimum operating condition of purified Persimmon polyphenols by single factor experiments. In the static adsorption and desorption, AB-8 macroporous resin showed the best performance of good adsorption and desorption, the static saturated adsorption capacity of 12.03mg/g, desorption rate of 95.18%. The experimental results show that liquid concentration and the impact on the rate of adsorption column effect, and the effect of elution by ethanol concentration, elution speed, as well as to determine the amount of eluting agent. The optimum adsorption conditions were as follows:speed of the column 2BV/h, concentration of liquid 0.352mg/mL, the best elution conditions is,80% ethanol concentration, elution flow rate of 2BV/h, washing volume from 4.0BV.3 Studied the oxidation resistance ability of persimmon fruit and persimmon leaf polyphenol through four kind of evaluation systems(ABTS,DPPH,FRAP,Hydroxyl free radical). The result indicated that in the persimmon fruit polyphenol's oxidation resistance ability research, the astringent persimmon variety displays the strong oxidation resistance ability; In the persimmon leaf polyphenol's oxidation resistance ability research, displays the obvious oxidation resistance ability.