Effects of chitosan and selenium treatments on retention of membrane integrity of guava (Psidium guajava']java L.) fruits during storage

The present study showed the effect of chitosan and selenium on membrane lipids and fatty acids of guava fruits during storage. The fruits were treated with selenium (0.02 ppm), chitosan (1.5%), and a combination of both and stored at room temperature (20 +/- 2 degrees C) and low temperature (5 +/- 2 degrees C). The membrane integrity was assessed by analyzing lipid constituents and fatty acids. Moreover, the activity of lipoxygenase was also determined. The total lipids were decreased in correlation with a reduction of polar and nonpolar lipids. In addition, unsaturation index of fatty acids also decreased by 3.7% and 8.9% at low and room temperatures, respectively. The treated fruits showed reduced lipid peroxidation as indicated by 21% lower activity of lipoxygenase enzyme. However, fruits stored at low temperature maintained 18% more lipids. The combined treatment of selenium and chitosan with low temperature storage was effective in the protection of membrane integrity.