Studies On Deacidification Of Orange Juice

Content of sugar and acid in citrus and ratio of them are the important index of flavor and quality of orange juice. The optimal ratio of sugar and acid is 10:1 ~ 15:1. Compared to overseas orange juice, domestic orange juice is too lower, which affects market competitive ability and inhibits development of domestic orange juice industry. So it is necessary to find an effective method for raising orange juice sugar acid ratio in food industry. According to a lot of researches nowadays, ion exchange resin and electrodialysis may be used in this field for the purpose of lower the acids in fruit juice. Till now, there is no demostic research report about application of electrodialysis and ion exchange on orange juice lowering.This paper includes two parts: the first one studied effects and affect factors of ion exchange resin on orange juice lowering. Static absorption characteristic of nine ion exchange resins were detected. According to the main physical and chemical characteristic before and after treatment, optimal ion exchange resin was chose. Then we studied the exchange adsorption static dynamics curve, dynamic curve and regenerated curve of this ion exchange resin in the process of decreasing citric acid, which help to formulate the optimal technological parameters of deacidification and resin regeneration. Secondly, characteristics of electrodialysis was studied simultaneously, physical and chemical characteristic of orange juice pro and post treatment was evaluated to select the most suitable electrodialysis installation for orange juice deacidification. Limiting current, effects of flow rate, voltage and temperature on deacidification process were discussed, and the reason of membrane pollution and way of abating pollution were also investigated.The main results and conclusions were summarized as follows:(1)210*7, L300,SD-315, IRA95,L400,D318,A7, D301,IRA67 could absorb citric acid in orange juice, but had different effect on quality of orange juice. L300 resin has strong ability of absorption on titration acid but a weaker ability on Vc, so L300 was chosen as the best resin for deacidification.(2) The static superficial adsorption of L300 resin was 3.47 g/100ml. Fruit acids adsorption quantity of L300 resin increased as adsorption time prolonged. Adsorption quantity tended to stabilization after four hours, which indicated its adsorption stabilization was four hours. Flow rate and temperature were the two important influencing factors of dynamic curve, but temperature had less effect on adsorption of L300 resin. Optimum condition were flow rate of 4 BV/h and temperature of 15℃.(3) Concentration, flow rate and temperature of regenerant were the main influencing factors...