Optimization of Enzymatic Hydrolysis Conditions for the Production of Crisp Plum Juice by Response Surface Methodology

Objective: To investigate the optimum enzymolysis extraction process conditions of plum fruit, and to provide theoretical bases fordeep processing andutilizationof itsresources. Method: The juice yield was used as an indicator. On the basis of single-factor experiments, response surface methodology (RSM) was employed to optimize the enzymatic hydrolysis pretreatment conditions for extracting fruit juice from crisp plum with methods of adding enzymes, including pectinases, cellulase and complex enzyme consisted of pectinases and cellulase. Result: The results suggested that the extraction parameters in the order of significance were enzymolysis temperature, enzyme concentration, enzymolysis pH, and enzymolysis time by response surface analysis. The optimum conditions of enzymolysis with pectinases were pectinases concentration 0.45 g/L, enzymolysis temperature 38 ℃, enzymolysis pH3.8 and enzymolysis time 72 min, in which the average juice yield of crisp plum was 78.63%. The optimum conditions of enzymolysis with cellulase were cellulase concentration 0.55 g/L, enzymolysis temperature 41 ℃, enzymolysis pH4.2 and enzymolysis time 105 min, in which the average juice yield of crisp plum was 74.33%. The optimum conditions of enzymolysis with complex enzyme were pectinases concentration 0.45 g/L, cellulase concentration 0.55 g/L, enzymolysis temperature 41 ℃, enzymolysis pH4.0 and enzymolysis time 87 min, in which the average juice yield of crisp plum was 81.51%. Conclusion: In the extract process of crisp plum juice, juice yields all increased when extracting juice, by adding pectinases, cellulase or complex enzyme consisted of pectinases and cellulose on the corresponding optimal conditions of enzymatic hydrolysis. The study provides technical references for the product development of Guizhou plum fruit.