高压微射流技术对红枣汁理化性质的影响

以红枣汁为研究对象，研究高压微射流对红枣汁理化性质的影响。将红枣汁分别采用不同压力（40、80、120、160、200 MPa）和不同处理次数（1、2、3、4 次）处理，分析高压微射流处理对红枣汁的ζ电位、平均粒径、色差、透光率、非酶褐变程度和可溶性固形物含量的影响。结果表明：在不同压力条件下的红枣汁的平均粒径、可溶性固形物、澄清度、非酶褐变程度和色差值有显著性差异（P＜0.05），160 MPa条件下处理4 次的红枣汁平均粒径最小，是对照组平均粒径的16.8%；160 MPa条件下处理2 次的红枣汁透光率达到最佳，为77.6%；120 MPa条件下处理4 次的红枣汁可溶性固形物含量达到最高，较对照组增加了29.6%；160 MPa条件下处理1 次的红枣汁非酶褐变程度最低，与对照组之间差异性不显著性（P＞0.05），160 MPa条件下处理1 次的红枣汁色差值L*最大。不同处理次数的红枣汁之间的电位有显著性差异（P＜0.05）。表明高压微射流可以改善红枣汁的理化性质，能够为消费者提供高质量的果汁。

Effect of High-Pressure Microfluidization on Physical and Chemical Properties of Red Jujube Juice

The effect of high-pressure microfluidization (HPM) on physicochemical properties red jujube juice was investigated. The juice was treated at five different pressures (40, 80, 120, 160 and 200 MPa) and each treatment was repeated for different times. Zeta potential, mean particle size, color, clarity, non-enzymatic browning index and total soluble solid content of the treated samples were evaluated. Mean particle size, total soluble solid content, clarity, non-enzymatic browning index and color values of the juice samples showed a significant difference (P < 0.05) at different pressures. The mean particle size of red jujube juice treated with 160 MPa for 4 times was the lowest, 16.8% as compared to the untreated samples. The best clarity of the samples treated at 160 MPa twice was observed, as demonstrated by a transmittance rate of 77.6%. The highest total soluble solid content was recorded in the samples treated at 120 MPa for 4 times, which revealed an increase of 29.6% in comparison to the control group. Single treatment at 160 MPa resulted in the lowest non-enzymatic browning index, with no significant difference observed compared with the control group (P > 0.05), as well as the highest L* value in red jujube juice. The samples treated for different times showed a significant difference in Zeta potential (P < 0.05). Conclusion: HPM could be used to improve physicochemical properties of red jujube juice, such as increasing total soluble solid content and clarity, and improving color positively resulting in a desirable high quality juice for consumers.