Theoretical models were proposed to predict simultaneous
heat and mass transfer during freezing and
storage but, in most of the published works, semiempiric
models were used. Aguirre Puente and Sukhwal
(1983) presented a detailed description of the heat and
mass balances that characterize the system, but without
solving them numerically; meanwhile Pham and Willix
(1984) suggested the use of simple equations based on
drying theory and on the use of the psychometric chart
to calculate weight loss only during frozen storage. They
considered a dried layer of constant thickness and its
resistance to heat and mass transfer; a similar approximation
is made by Tocci and Mascheroni (1995a) in their study of heat and mass transfer during food
freezing.