ABSTRACT
The desirable effect of heat (from fire) on the taste of foods of animal and plant origin, especially seeds, tubers, and roots, was probably accidentally discovered, following a natural forest fire, by our ancestors long before civilization. They also possibly recognized that heated foods did not spoil as rapidly as raw foods or cause health hazards. Since then, particularly following the invention of pottery and ovens, heat has been used to roast, boil, bake, and concentrate foods to improve taste and to enhance shelf life (and probably safety). However, it was not until approximately 1810 that extended shelf life of perishable foods was achieved by a specific method, appertization. Nicolas Appert, after whom the method was named, in France, reported that by filling a clean glass jar with a desirable food, heating the contents in boiling water for six hours or more, and hermetically sealing the container with a cork kept the food unspoiled and safe for a long time. 1 Some of his products (meat stew) prepared in 1824 were found nontoxic when opened in 1938 but were found to contain dormant spores. Heating of foods in cans was developed by Durand in England in 1810, and by 1820, the method was used in the United States. Methods to reduce the heating time to approximately 30 minutes were also developed by adding different types of salts to the water to raise the boiling point above 212°F (100°C). In 1870, the autoclave was invented, providing the possibility of developing pressure vessels that could be used to heat canned food at a much higher temperature for a relatively shorter period of time in order to retain the quality of foods as well as to enhance shelf life.
