冷冻与酶解相结合澄清芦柑果汁的工艺研究及质量评价

Study on the technology and quality evaluation of freezing and enzymatic hydrolysis in clarifying ponkan juice

研究冷冻法与果胶酶酶解法相结合对芦柑果汁的澄清作用,同时探讨此澄清方式对果汁品质的影响。实验以新鲜芦柑果肉为原料,先进行冷冻预处理,自然解冻榨汁、离心后再用果胶酶对果汁进行澄清。结果表明,芦柑果肉冷冻预处理的最佳温度为-20℃、时间为60min,得到的果汁透光率和出汁率分别为80.57%、82.86%;果胶酶酶解的最优工艺参数为:酶添加量0.05g/L、酶解温度45℃、酶解时间0.5h,酶解处理后果汁的透光率和出汁率分别达到94.16%、90.38%;经冷冻与酶解相结合处理后汁液的Vc含量由26.77mg/100g降为25.48mg/100g,可溶性固形物及总糖下降较多,分别由9.6%、10.2g/100mL降为8.4%、7.8g/100mL,果胶和可溶性蛋白质几乎被完全分解;澄清汁储存稳定性良好。因此,该复合澄清工艺合理可行,可为芦柑果汁的深加工提供理论依据。

The clarifying effect of freezing method and pectin enzymatic hydrolysis method on the ponkan juice was studied.And the effect of the clarification method on the quality of juice was also discussed.In the experiment,fresh ponkan pulp was taken as raw material,which was pretreated by freezing,pressed by natural thawing,and then,pectinase was used to clarify the juice after centrifugation.The experimental results show that the best ponkan pulp freezing pretreatment temperature is -20 ℃,time for 60 min, transmittance of juice was 80.57% and the juice yield was 82.86%;Pectinase enzyme solution of the optimal process parameters are:enzyme addition 0.05 g/L,enzymolysis temperature 45 ℃,enzymolysis time 0.5 h,transmittance of juice was 94.16% and the juice yield was 90.38% after enzymolysis processing.After treated by the combination of freezing and enzymatic hydrolysis,the Vc content of the juice slightly decreased from 26.77 mg/100 g to 25.48 mg/100 g,and the soluble solids and total sugars decreased significantly from 9.6%,10.2 g/100 mL to 8.4% and 7.8 g/100 mL.Pectin and soluble protein were almost completely decomposed.Clear juice storage is stable.Therefore,the composite clarification process is reasonable and feasible,which can provide theoretical basis for further processing of ponkan juice.