A meta‐analysis of the effects of ultrasonic pretreatment on the characteristics of dried fruits and vegetables
Parameter selection in ultrasonic pretreatment is closely related to the quality of dried fruits and vegetables, so it is essential to investigate the impact of various parameters of ultrasonic pretreatment on the product quality. In this paper, data from 67 relevant literatures were collected to evaluate the effects of ultrasonic pretreatment on dried fruits and vegetables through meta-analysis. Overall, the findings indicated that ultrasonic pretreatment could shorten drying time, reduce hardness and improve color appearance of dried products. Subgroup analysis showed that high power ultrasound (P ≥ 300 W) could increase total phenol content and antioxidant activity of dried fruits and vegetables. Additionally, applying short-duration ultrasound (t < 15 min) increased antioxidant activity, while medium-duration ultrasound (15 min < t < 30 min) simultaneously enhanced flavonoid content and antioxidant activity. In summary, the application of ultrasonic pretreatment has a positive impact on processing high quality dried fruits and vegetables and obtains better-quality products in a shorter time compared to direct drying technology. https://doi.org/10.1111/jfpe.14689
