Advances in Evaluations of Damage of Postharvest Fruits and Vegetables

Progresses in evaluations of damage of postharvest fruits and vegetables are reviewed. Visual inspection is simple but useful method to assess physical damage, such as bruising and crack; however, it can relatively be less reliable. Generally, instrumental measurements are often preferred over sensory evaluations in laboratory and commercial situations because they reduce variations in judgment among individuals and provide a common language among researchers, industry and consumers. Energy absorption and sonic and ultrasonic vibration may reflect the status of internal damage, but both techniques are more suitable for assessing bruise susceptibility. Compared with application of fluorescence and delayed light emission to chlorophyll containing fruits and vegetables, optical absorbance to all fresh produce is widely tested to evaluate damage. However, these methods developed are essentially for detection of physical damage. For researchers and industry, an exciting prospect arises from a better understanding of internal damage of fruits and vegetables during postharvest handling and distribution. X ray analysis, magnetic resonance imaging, and laser inspection can now be used to detect the internal damage in some limited application; but not practical for routine damage testing because the equipment is expensive. Like all other technologies, costs and capabilities are rapidly improving. Other techniques related to physiological activities, such as respiration rate, ethylene evolution rate, and leakage rate, are also developed, and, furthermore, the increasing sensitivity of the equipment could make these techniques more available. Since internal damage comprises many properties or characteristics, and each method is based on the measurement of a given property, it is important to mathematically combine each measurement and then to exactly reflect the damage. It is expected that a battery of several detectors can produce a fingerprint that may indicate presence or degree of damage of postharvest fruits and vegetables.