| Summary: | 碩士 === 國立中興大學 === 園藝學系所 === 101 === Taiwan is an oriental fruit fly quarantine area. Therefore, vapor heat quarantine treatment is necessary before the export of papaya fruits. Besides, papaya fruits are also susceptible to disease caused commercial loss during storage, transporting and marketing. Previouse research, hot water treatment is able to control the pathogen infection in papaya fruit. Therefore, this study is to evaluate to effect of combinafion of hot water and vapor heat treatment on fruit disease control and the influence on color change of fruits’ peel. Furthermore, this study also investigated the changes of the antioxidant content and antioxidant enzymatic activity of papaya fruits under 25℃ for 24 hours after the hot water treatment and the time after the vapor heat treatment.
For the winter fruits, 57℃ hot water treatment for 90 seconds caused heat injury. On the contrary, the summer fruits had no sign of heat injury either in 55℃ or 57℃ hot water treatment for 90 seconds. Undergoing a vapor heat treatment immediately after a hot water treatment had led the declination chlorophyll fluorescence value and inhibited the color change of the fruits’ peel. This phenomenon also followed the decreasing of chlorophyll fluorescence, increasing in hydrogen peroxide (H2O2) content and no significant changed in the activity of antioxidant enzyme. However, placing at 25℃ for 24 hours after hot water treatment then vapor heat treatment significantly improved the color change of fruits’ peel which might due to the recovery of chlorophyll fluorescent value and H2O2 content and increasing in antioxidant enzyme like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD). Meanwhile, when the fruit placed at 25℃ for 24 hours after hot water treatment then vapor heat treatment found only CAT and APX had significantly increased. All of the treatments in this study had no significant influence on the electrolyte leakage, malondialdehyde (MDA), antioxidant capacity (FRAP), ascorbic acid (AsA), and total phenolic compounds (TPC).
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