Recent developments in freezing of fruits and vegetables: Striving for controlled ice nucleation and crystallization with enhanced freezing rates.

Fruits and vegetables are rich in essential nutrients such as minerals, vitamins,
and antioxidants; however, they have short shelf life. Freezing is a superior
method of preservation compared to other techniques with respect to nutrient
retention and maintenance of sensory attributes. However, several physical and
textural quality changes associated with freezing and thawing pose a serious
problem to the quality of frozen products. Some of the disadvantages associated
with the currently employed methods for freezing fruits and vegetables include
low rates of heat exchange in blast freezers, shape limitation in plate freezers,
high cost of operation in cryogenic freezing, and freezing solution dilution in
immersion freezing. Therefore, novel freezing technologies have been developed
to achieve controlled ice nucleation and crystallization, enhanced freezing
rate, decreased phase transition time, and maintained temperature stability. This
review discusses some of the most recent approaches employed in freezing and
points to their adoption for maintaining the quality of fruits and vegetables with
extended storage.