酶解澄清工艺对葡萄汁品质的影响

Effect of enzymatic clarification on grape juice quality

将常用制汁葡萄品种玫瑰香,在二次浸提压榨取汁后,分别采用不同的加酶量和不同的酶反应时间,与未酶解葡萄汁样品比较,考察酶解工艺对葡萄汁品质相关因素的影响。结果发现,酶解处理可以提高葡萄汁的澄清度和Brix值,降低可滴定酸含量和pH。由于果胶酶降解了果汁中的果胶物质,降低了葡萄汁的悬浮稳定性,因此随着加酶量的增加和酶解时间的延长,果汁贮藏期间的沉淀量有所增加,同时,葡萄汁的褐变程度也有所加剧,使得总色度中褐变反应占据主导。经过酶解处理的样品与未处理样品之间的色泽显示出明显差异(△E>2)。研究发现,加酶量0.015%、反应时间60min是比较合适的酶解工艺条件。

A study was made of enzymatic clarification on the quality of the juice extracted by twice pressing from Muscat grape.Several conditions were examined,within a pectinase concentration range of 0.01% to 0.03%,and time of treatment from 20 min to 100 min.Results showed that the juice samples treated with pectinase got higher value on Brix,clarity,and got lower value on pH,titratable acidity.The precipitation capacity during storage and the browning of juice samples both increased along with the pectinase concentration and the treatment time increasedy,since the suspension stability would be destroyed by pectinase treatment.The colors of treated and untreated samples showed significant difference（△E2）.The 0.015% pectinase concentration and 60 min treatment time would be appropriate technological parameter.