Better sensory quality is obtained in frozen foods but at a cost if increased energy requirement to maintain them, in a frozen state. Dried fruit products such as raisins and prunes offer very different attributes than their fresh counterparts. The consumer judges canned products with a different set of criteria than frozen or fresh items of the same commodity.
Fresh fruits and vegetables are perishable, i.e., they have limited shelf life. They are living, respiring tissue that is also senescing and dying. Certain fruits such as bananas and tomatoes will ripen after harvest, developing desirable color, texture, and flavor during handling and storage. All other fruits and vegetables such as oranges, grapes, cucumbers, and carrots will show little or no improvement in quality within the postharvest system.
Packing and handling systems have been developed to move the product from farm to consumer expeditiously to minimize quality degradation. Techniques used to extend shelf life of fresh products include
Lowering the temperature to slow respiration and senescence
Maintaining an optimal relative humidity to slow water loss without accelerating decay
Adding chemical preservatives to halt physiological and microbial losses
Maintaining an optimal gaseous environment to slow respiration and senescence Longer shelf life can also be obtained by selecting cultivars that are more able to withstand the rigors of the handling system and by harvesting a crop at optimal maturity for storage and handling.
Shelf life of a product
