Six general methods of food preservation generally used industrially and at home may be classified in terms of the major
controlling treatment
1) Use of high temperatures
· To destroy both
microorganisms and enzymes
· Examples include pasteurization of milk and fruit juices and canning
2) Use of low temperatures
· To control growth of microorganisms
· Examples include root storage of fresh vegetables, refrigeration, and freezing
3) Removal or tying up of moisture
· To control microbial growth
· Examples include drying, freeze drying, adding large amounts of sugar as in jelly making
4) Addition of chemical preservatives
· To inhibit microbial growth
· Examples include development of acid in fermenting pickles, addition of antioxidants to lard and other fats, addition of propionates to bread as anti-molding agents
5) Keeping microorganisms out
· Keeping microorganisms out
· Examples include sterilized foods and packaging foods
6) Use of ionizing radiations
· To destroy microorganisms and control enzyme activity
· Examples include the experimental use of pasteurizing radiation dosages for fresh strawberries and radiation of fresh potatoes to inhibit sprouting.Methods of food preservation generally used industrially and at home may be classified in terms of the major controlling treatment