Effect of thiamin treatment on antioxidant enzyme activity and chilling injury of Elberta peach (Prunus persica L.) fruit during postharvest storage

In the present study, the effect of thiamin on chilling injury of Elberta peach fruit was investigated. Thiamin at the concentrations of 0, 100, and 200 mg l- 1 was effective in reducing the incidence of chilling injury in Elberta peach fruit during 25 days storage at 0 degrees C. In fact, thiamin at concentrations of 200 mg l- 1 showed the best effect. Also, thiamin treatment reduced the lipid peroxidation and peroxide hydrogen content of peach fruit during storage. Results of physiological response in peach fruit showed that thiamin induced the activity of antioxidant enzymes, including catalase, peroxidase, superoxide dismutase, ascorbate peroxidase, and DPPH radical scavenging activity. These results indicate that the elicitation of an antioxidant response in peach fruit by thiamin may be associated with chilling injury alleviation. Moreover, thiamin maintained the peach quality by decreasing the lipid peroxidation and peroxide hydrogen content. The present study is the first evidence that shows thiamin increases peach fruit tolerance to cold stress and therefore enhances the fruit quality. So, the fruits treated with 200 mg l- 1 thiamin showed the best effect.