Study On The Debitterring And Processing Techniques Of Guanxi Pomelo Juice

Guanxi pomelo is very famous in the world due to its good qualities, such as good taste, high edible ratio, rich nutrition and so on. In 2008 year, the yields of Guanxi pomelo has achieved 700,000 t, but the processing capacity is less than 1% of its yield. The main reason is unacceptable bitterness which is difficult to reduce from pomelo juice. This paper studied the processing technology of pomelo juice,and focus on the method to remove bitter taste mainly. This work will be contribute to raise the added-value of Guanxi pomelo and enrich produce of fruit juice on market.First,β-Cyclodextrin(β-CD), enzyme, and resin were debittered the pomelo juice.The resin adsorption was the best way to remove bitterness according to the result of sensory taste and physico-chemical analysis experiment.So the resin adsorption method debittered juice were adopted.Second,the properties of adsorption and desorption of 12 macroporous resins were studied by static adsorption experiment.The results showed that R5, R9 and R7 had the higher adsorption capacity in the 12 resins and their adsorption rate of naringin were 63.2%,68.7%, 73.7% respectivly. According to classical Langmuir equation and resin price,R5 was the best one of them ,so the R5 resin was selected for futher debittering reaserch.Third,the adsorption and desorptin properties of R5 resin were studied with dynamic experiment.The results showed that the optimum condition of adsorption were flow rate 5BV/h,operating temperature 25℃and colum height to diameter ratio 10:1.The optimum desorption condition were 70% ethanol, flow rate 2BV/h, operating temperature 25℃.Finally,the major processing technology of pomelo juice were studied. The optimum parameters of clarifying technology is dealing juice with 0.01% pectinase and 0.005% cellulase at 40℃for 40min. The concentration technology was vacuum evaporation concentration at 50℃The formula of pomelo juice was as follow:100g pomelo juice,1.0g fructose syrup,1.5g sucrose,0.09g citric acid,0.020g sodium citrate.