Both impact and compression bruising can cause significant damage, discolor tissues, and detract from the visual and eating quality of the commodity. Even when browning does not occur, such as in the case of bruised strawberry fruit, the damaged areas look unattractively dark. Vibration injury occurs after harvest when the products rub against each other or the carton trays during transport. A good example of this is the dark scuff marks on the skin of pear fruit when it ripens. The first of these is senescence problems.
Senescence is defined as the phase of plant growth after full maturity that results in tissue death.
This condition typically shows up as tissue browning. More rapid than normal senescence and development of brown flesh can indicate that the nutrient composition of the product is poor. A good example is senescent breakdown of apples, a condition that is associated with low calcium in the fruit. The second set of postharvest problems is chilling injury. Whereas most apples, stone fruit, and vegetables such as asparagus, cabbage, lettuce and onions should be stored close to 32 F to maximize storage life, many products, especially those of sub-tropical or tropical origin develop chilling injury if stored at too low of a temperature.