Abstract: 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.

Key words: red jujube juice, high-pressure microfluidization, physical and chemical property