The Processing Technology Of Diospyros Lotus L.Juice And Antioxidant Activity Of Polyphenols In Vitro

In this study,Diospyros lotus L.was raw material.The key technologies(enzymolysis,clarification,station)and the antioxidant capacity of Diospyros lotus L.juice and cloudy juice were investigated.Using response surface methodology to analysis composite enzymatic technological parameters for Diospyros lotus L.juice jield,the condition was optimised.Compare the effect of different ways to clarify Diospyros lotus L.juice,and the effect of different stabilisers for Diospyros lotus L.cloudy juice.The antioxidant capacity in vitro of Diospyros lotus L cloudy juice was evalated.The results are as follows:(1)The optimum extraction condition was obtained by RSM as followed,the ratio of compound enzyme(pectase:cellulase)was 5:4,the dosage of compound enzyme was0.32g/100 g,the temperature was 45.67? and the extraction time was 1.57 h with verified juice yield attending 69.75%.The effect of compound enzyme and the juice yield became better.(2)Diospyros lotus L.juice was treated by membrance and different clarifying agents(chitosan,bentonite,PVPP).The best clarification effects was 2 ?m membrance,and the effect on transmittance up to 95.4%.The effect of using clarifying agents indicated the best effect on optical transmittance up to 94.3% was observed in Diospyros lotus L.juice treated with chitosan at the concentration of 0.3 g/L,and the clarifying agents of Diospyros lotus L juice treated with chitosanis better than bentonite,the clarifying agents of PVPP is the worst in three clarifying agent.(3)The effects of stabilisers treatment on suspension stability of Diospyros lotus L.cloudy juice were investigated.Through single factor experiment it showed that when the dosage of xanthan gum,carrageenan,CMC-Na were 0.8 g/L,0.6 g/L,0.8 g/L.Orthogonal test was used to optimize the dosage of stabilizers:the influencing degree of three factors is xanthan gum(A)>carrageenan(B)> CMC-Na(C),the dosage of xanthan gum was0.8g/L,the dosage of CMC-Na was 0.6g/L,the dosage of carrageenan was 0.6g/L.(4)The extracts are identified and quantified by HPLC.Results show that the polyphenols in Diospyros lotus L.cloudy juice was gallic acid,protocatechuic acid,catechinic acid,chlorogenic acid,epicatachin,ferulic acid,gallogen,phlorizin,Quercetin,gallic acid andcatechinic acid is the most abundant phenolic compound.The juice of treatment for membrance,the content of gallic acid,protocatechuic acid in the treatment by membrance is more than other clarification methods,catechinic acid was less than others.Defferent treatments for Diospyros lotus L.cloudy juice influence the quality and antioxidant capacity in vitro.After enzymatic,total phenolic and total flavonoid substances were increased significantly,so its antioxidant capacity in vitro is the maximum.The influence for Diospyros lotus L.cloudy juice quality and antioxidant capacity that treated by membrane filtration is the lowest,on the contrary,the quality and antioxidant capacity treated by clarifying agents were decreased significantly.Therefore,membrane filtration is the better way to clarify the Diospyros lotus L.juice.