The relationship between lipid oxidation and antioxidant content in postharvest vegetables

Lipid oxidation is the quality Limiting attribute in many vegetables that generates off-flavors. Lipoxygenases, which catalyze the oxygenation of polyunsaturated fatty acids are key enzymes in this pathway and their presence is believed to be the chief reason for the need for blanching (i.e., inactivation of enzymes) enabling frozen storage. Off-flavor production in legumes, such as garden peas, is a particular problem, due to high levels of this enzyme found in these seeds. The lipid oxidation pathway is triggered in response to tissue wounding which occurs during mechanical harvesting of peas in the field. Bruised peas that are not blanched develop strong off-flavors within a few hours. A number of studies has shown that antioxidants are consumed during lipid oxidation. Vitamin C (ascorbate) is an antioxidant and also an important micronutrient in peas. It is possible that the level of vitamin C is affected by the progress of lipid oxidation in postharvest peas.