Competitiveness of Vacuum Steam Thawing in Four Typical Novel Thawing Methods: A Review

The vacuum steam thawing (VST) is to thaw frozen food by condensation heat exchange in a vacuum environment. Recently, the VST has gained attention due to the excellent thawing effect, such as a rapid thawing rate, high water holding capacity, and great antimicrobial capacity. This paper reviews the mechanism and application of VST, ultrasound thawing (UT), microwave thawing (MT), and electric field thawing (EFT), and analyzes the competitiveness of VST in these four novel thawing methods. The localized overheating phenomenon is the common disadvantage of UT, MT, and EFT. Based on the condensation heat exchange mechanism and the low-temperature and low-oxygen vacuum environment, even thawing can be achieved by VST. In addition, compared to UT, MT, and EFT, the quality of frozen food thawed by VST is much better. Moreover, two kinds of optimization of VST are summarized, which are thawing combined technology and vacuum sublimation-rehydration thawing (VSRT). The thawing combined technology aims at the complementarity role among VST and other thawing technologies. The VSRT aims at improving the effect of condensation heat exchange. These two techniques improve the thawing effect of VST and effectively reduce the cost requirements, which can be the research direction of VST in the future. Further refinement of these two techniques will have a positive impact on the thawing process in the food industry.