The freezing of foods slows down, but does not stop, the physical and
biochemical reactions that govern the deterioration of foods. When pro
perly handled and processed, frozen foods are often perceived to have
superior sensory and nutritional qualities to foods preserved by other
methods. These qualities depend upon the control of the freezing proc
ess and upon careful pre-freezing preparation and post-freezing storag
e of the product. New insights into the physicochemical aspects of eac
h stage of frozen food production has diagnosed sources of quality los
s and identified appropriate strategies for improving the quality of f
rozen foods. Comparison of the freezing operations currently used indi
cates a trend towards more rapid freezing, although at present the tra
de-off between freezing rate and freezing economy may best be balanced
by means of combination freezing processes.