前处理方式对预腌萝卜果胶酶活性和脆度的影响

Effect of pretreatment method to pickled radishes on the activity of pectinase and brittleness

以白萝卜为材料,研究了热风干燥、热烫和高盐预腌渍等泡菜常用的前处理方式对其果胶酶活性的影响,同时观察原料脆度变化。实验表明,在模拟秋季室外晾晒条件即30℃热风干燥条件下,萝卜果胶酶活性先升高后降低,同时萝卜脆度也有不同程度下降,跟失水量密切相关,萝卜最佳失水量为35%,此时脆度下降约45%,果胶酶活性降低约20%;在热烫条件下,温度越高,萝卜果胶酶活性降低越快,最佳热烫条件为60℃、10min,此时原料脆度降低15%,果胶酶活性降低约27%;盐浓度对果胶酶活性的影响有显著影响,在低浓度盐条件下(NaCl<4%),盐腌渍对酶活有促进作用,在高浓度盐条件下(NaCl>6%),盐腌渍对果胶酶酶活有显著抑制作用。综合考虑前处理方式对萝卜原料果胶酶活性的抑制和脆度的影响,高盐预腌渍效果更好。

Radishes were used as raw material to study on three commonly pretreatment methods including heated-air drying,blanching and high-salt pickling,activities of pectinase and brittleness were investigated. The result showed that,in the conditions of 30℃ hot-air which imitated the outside temperature in autumn, activities of pectinase of radishes rose at beginning and then declined,the brittleness of radishes declined too, changes were closely related to the water loss,losing 35% water was the optimum condition,as a result of that the brittleness dawn to 45% and the the activity of pectinase falt 20%. Different conditions of blanching had an enormous impact on the activities of pectinase.The result indicated that the optimum condition was 60℃, remaining 10min,under these conditions,as a result of that the brittleness dawn to 15% and the activity of pectinase fell 27%.Sodium concentration had significant effect on the activity of pectinase. In the low-salt condition （NaCl〈4%）, pickling could increase the activity of pectinase,in the high-salt condition （NaCl〉6%）, pickling could reduce the activity of pectinase. These factors taken together,pretreatment methods influenced on the activity of pectinase and brittleness. Given the influence on the activity of pectinase and brittleness by different pretreatment methods, high-salt pickling in the beginning was the best method.