ABSTRACT
Using low temperature to preserve foods dates back to the prehistoric times when man stored meat of hunted game in snow and blocks of ice. Refrigeration and freezing are unit operations that extend the shelf life of perishable food products based on the well-known principle in physical chemistry which states that molecular mobility is depressed and consequently chemical reactions and biological processes are slowed down at low temperature. The reaction rate rule governs the deceleration of deteriorative changes in food products by refrigeration and freezing according to which decreasing temperature of the product by 10°C reduces the reaction rate by half.
