ABSTRACT
The primary reason for processing foods is for preservation in order to free man from total dependence on geography and climate in providing for his nutritional needs and wants. Foods are also processed for other reasons such as to remove inedible or less-digestible portions, to destroy harmful bacteria, to make foods more palatable or nutritious, or to make them more convenient for the consumer. Heat processing of foods is carried out to increase storage life and to minimize the occurrence of diseases caused by food-carried bacteria. Examples of heat processing include blanching, pasteurization, and sterilization. Although such processing make foods available throughout the year instead of only during short harvesting periods, the thermal treatments entail some losses of vitamins. Blanching prior to freezing or drying is used primarily to inactivate enzymes that can lead to quality deterioration in storage. When applied prior to canning, blanching involves treatment with boiling water or steam. Microwave heating and hot-gas blanching are also used.
