Peroxidation of membrane lipids in minimally processed cucumbers packaged under modified atmospheres

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2002
Karakaş, Barçın
Peroxidation of membrane lipids is an inherent feature of ripening and senescence of plant tissues. Increased lipid peroxidation has also been observed in the development of chilling injury in susceptible tissues. In this study, the effect of storage conditions and physical tissue damage on membrane peroxidation of minimally processed cucumber (Cucumis sativus, L.) was investigated. Model modified atmospheres were achieved passively by storage of the minimally processed cucumbers at 4°C and 20°C in hermetically sealed jars. Treatments such as oxygen flushing of the packages and bruising of the fruit previous to sealing resulted in different atmospheric compositions and respiration rates. Lipid peroxidation in samples packaged under these conditions of modified atmosphere packaging (MAP) and also in covered petri plates (non- MAP) were determined by the FOX2 method. The TBARS assay was also carried out as an alternative assessment of lipid peroxidation. The initial level of lipid hydroperoxides and TBARS were found as 48-59 umoles H2O2 equivalents and 0.11-0.20 nmoles MDA equivalents per gram. The results of the two assays correlated significantly for nonbruised samples. The levels of lipid hydroperoxides increased by 2-5 fold in chilled non-MAP tissues and MAP was effective in reducing the generation of lipid hydroperoxides and TBARS. The effect of dipping solutions containing CaCİ2 and/or ascorbic acid on the development of lipid hydroperoxides investigated in non-MAP tissues had varying results. Tissue hardness of MAP samples increased for the first 3 days for all tissues but chilled tissues started to soften on the 6th day.

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Citation Formats
B. Karakaş, “Peroxidation of membrane lipids in minimally processed cucumbers packaged under modified atmospheres ,” M.S. - Master of Science, Middle East Technical University, 2002.