工艺条件对杀菌型褐色乳酸菌饮料稳定性的影响

为了提高杀菌型褐色乳酸菌饮料的稳定性，对与产品稳定性密切相关的3个因素（褐变时间、均质压力和果胶用量）首先进行了单因素试验。进一步以褐变时间、均质压力和果胶用量为自变量，以粒径、zeta电位、离心沉淀率和不稳定指数为评价指标进行L9（34）正交试验。结果表明，当褐变时间160 min、均质压力25 MPa、果胶用量 2.5 g/L时，体系的不稳定指数值最小。获得最佳褐变时间、均质压力和果胶用量分别为165 min、22 MPa和2.8 g/L。此优化条件下，杀菌型褐色乳酸菌饮料粒径（723 nm）、离心沉淀率（1.71%）和不稳定指数（0.737）最小、zeta电位绝对值（-4.88 mV）最大。

Effect of process conditions on the stability of pasteurized brown lactic acid bacterial beverage

In order to improve the stability of the pasteurized brown lactic acid bacterial beverage,three factors closely related to the stability of the product,namely browning time,homogenization pressure and pectin dosage,were tested by single factor tests.Furthermore,L₉(3⁴)orthogonal tests were carried out using browning time,homogenization pressure and pectin dosage as independent variables,and the particle size,zeta potential,centrifugal precipitation rate and instability index as evaluation indexes.The results showed that the instability index of the system was the smallest when browning time was 160 min,homogenization pressure was 25 MPa and pectin dosage was 2.5 g/L.The optimum browning time,homogenization pressure and pectin dosage were obtained,which were 165 min,22 MPa and 2.8 g/L,respectively.Under the optimal conditions,the particle size(723 nm),centrifugal precipitation rate(1.71%)and instability index(0.737)of the pasteurized brown lactic acid bacterial beverage were the smallest,and the absolute value of zeta potential was the largest(-4.88 mV).