Recent advances in the improvement of freezing time and physicochemical quality of frozen fruits and vegetables by ultrasound application

Freezing is widely used for the preservation of fruits and vegetables (FVs). Whereas, the conventional freezing method presents low process efficiency in frozen FVs. Ultrasound application is used as a supplementary technology to improve the freezing process of FVs. This reviewed paper shows the cavitation effect of ultrasound and the effect of ultrasound application on freezing time and the physicochemical quality of frozen FVs. The cavitation effect of ultrasound in the freezing process was described in detail. Compared with conventional freezing, ultrasound application in freezing of FVs can shorten the freezing time, and improve physicochemical quality including drip loss, colour, firmness, chemical compositions (ascorbic acid, total phenolic and anthocyanin), as well as microstructure. Therefore, the results of these studies illustrated that ultrasound is a potential technology to enhance freezing efficiency and retain the quality of FVs during freezing.