|Hodges, D. Mark - AGRI-FOOD CANADA|
Submitted to: American Society for Horticultural Science
Publication Type: Proceedings
Publication Acceptance Date: February 2, 2004
Publication Date: August 4, 2004
Citation: Hodges, D., Lester, G.E. 2004. Oxidative stress: postharvest fruit and vegetables. American Society for Horticultural Science. 39(5):922-923. Interpretive Summary: The interpretive summary is not required for Abstract presentation.
Technical Abstract: All aerobic organisms require oxygen as an essential component of their metabolism. However, the onset of oxidative stress, which occurs when the production of active oxygen species (AOS) such as O2, H2O2, and OH exceeds the scavenging capacity of the organism, profoundly affects postharvest storage quality and longevity of horticultural commodities. Postharvest oxidative stress can arise from both external factors, such as stressful storage protocols and physical damage, as well as from internal metabolic modifications, such as those associated with senescence and/or ripening. Those factors can directly and/or indirectly influence levels of AOS, which are regulated by their rates of generation, of reaction with target molecules (proteins, lipids, and/or nucleic acids), of degradation, and of scavenging/neutralization by enzymic and/or non-enzymic antioxidants. Although the sources, severity, and modes of AOS generation may differ, once excess levels of AOS are produced, they can auto-catalyze their own production through damage to lipids and proteins. The mediation of AOS levels and oxidative stress in postharvest material is therefore multi-factorial. Recent research into the effects of oxidative stress on postharvest quality of horticultural commodities such as spinach and honeydew melon will be discussed.