In this study, ultrasound-assisted vacuum drying (UAVD) was employed as a new approach to improve the efficiency and produce dried hawthorn fruit juice powders with acceptable quality. To achieve these goals, the effects of ultrasound intensity (at four levels of 15.29, 20.38, 22.93 and 24.46 kW/m²) were evaluated. The results showed that UAVD significantly shortened the drying time (P < 0.05), and with the increasing ultrasound intensity, the drying rate increased and the drying time decreased. Based on statistical tests, the Page model was found to fit well to the drying kinetics. After drying, a decline in quality of fresh juices was observed. As compared with vacuum drying individually, UAVD significantly reduced the colour degradation, and increased the retention of the total flavonoids content, five flavonoid compounds contents and antioxidant activity. It was shown that UAVD at the higher ultrasound intensity varied from of 20.38 to 24.46 kW/m² contributed to a better quality in the dried juice powders. Overall, this study demonstrates that UAVD is a promising technique for improving the drying efficiency and quality retention of hawthorn fruit juices.

在这项研究中，采用超声辅助真空干燥（UAVD）作为提高效率和生产质量合格的山楂果汁粉的新方法。为了实现这些目标，评估了超声强度的影响（分别为15.29、20.38、22.93和24.46 kW / m ^2的四个级别）。结果表明，UAVD显着缩短了干燥时间（P <0.05），并且随着超声强度的增加，干燥速率增加，干燥时间减少。根据统计测试，发现Page模型非常适合干燥动力学。干燥后，观察到新鲜果汁的质量下降。与单独进行真空干燥相比，UAVD显着减少了颜色降解，并增加了总黄酮含量，五种黄酮化合物含量和抗氧化活性的保留率。结果表明，较高的超声强度下的UAVD在20.38 kW / m ²至24.46 kW / m ^{2之间变化，}有助于干燥果汁粉的质量更高。总体而言，这项研究表明，UAVD是提高山楂汁的干燥效率和保质期的有前途的技术。