Author
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Wang, Chien |
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Submitted to: Postharvest International Symposium Proceedings
Publication Type: Proceedings Publication Acceptance Date: 5/31/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Chilling injury is a problem in most crops of tropical or subtropical origin. About one-third of all fruits and vegetables in U.S. markets are susceptible to chilling injury. Symptoms of chilling injury such as pitting, discoloration, internal breakdown, and decay can result in large postharvest losses during marketing. Therefore, it is important to reduce chilling injury. We have found that several techniques were able to either retard the development of chilling injury symptoms or increase the resistance of the tissues against chilling injury. These techniques include low temperature conditioning, heat treatment, intermittent warming, controlled atmosphere storage, treatments with calcium or other chemicals, waxing, film packaging, genetic modification, and applications with ethylene, abscisic acid, methyl jasmonate, polyamines, or other natural compounds. Proper implementation of these techniques in the commercial situation should reduce the postharvest losses of fruits and vegetables. Technical Abstract: Postharvest techniques which have been shown to alleviate chilling injury include low temperature preconditioning, intermittent warming, heat treatment, controlled atmosphere storage, treatments with calcium or other chemicals, waxing, film packaging, genetic modification, and applications with ethylene, abscisic acid, methyl jasmonate, polyamines, or other natural compounds. Low temperature conditioning and intermittent warming maintain high levels of phospholipids, increase the degree of unsaturation of fatty acids, increase the levels of spermidine and spermine, and stimulate the activities of free radical scavenging enzymes. Heat treatment induces heat shock proteins, suppresses oxidative activity, and maintains membrane stability. Methyl jasmonate can activate lipoxygenase gene expression and induce synthesis of abscisic acid and polyamines. Polyamines may act as free radical scavengers and membrane stabilizers. All of these processes can enhance chilling tolerance of tissues and alleviate chilling injury of fruits and vegetables. |
