Engineering Preservation of Food Products by Heat

Food engineering is known to world from past several years but it is improving its impact from last 100 years. Preservation of food by using heat treatment is considered as first invented technique for preserving food or for extending shelf life of food product. In early years this method was constrained by misunderstanding that air caused food spoilage. But in 19^th century several researchers started use of steam i.e. temperature above boiling point of water is used for heat treatment of food products. Further they started use of salt or calcium chloride in process water to increase boiling point solution and to improve heat treatment. That solution of water and salt or calcium chloride is called as brine solution. As calcium chloride gave higher boiling point than common salt and microbial growth in the acidic food is higher than basic so in next few year researchers increased use of calcium chloride instead of common salt.  Hence in food industry for heat preservation of bottled and canned foods use of calcium chloride is increased.

The more useful study of ‘commercial sterilization of low acid foods stored in different containers’ was conducted in last decade of 19^th century in Boston. This study was conducted by Prof. Samuel C. Prescott with Willam Underwood and they concluded that time at temperature needed to obtain commercial sterilization of food products packed in different containers. This study gave proper set up for the preservation of food by heat treatment. This study helped food engineers to develop graphical models for the time and temperature study to obtain commercial sterilization of canned food. During 1925 C. Olin Ball first time used computer based model for heat inactivation kinetics of Clostridium Botulinum. In next decade after this model Stumbo worked on this kinetics of microbial inactivation. The mathematical models developed by these both C. Olin Ball and Stumbo are basis of heat preservation methods used in food processing.