Postharvest of two strains of nam dok mai mango from Northern Thailand under different temperatures using various wrapping materials

The commercial ripe fruit of two strains of 'Nam Dok Mai' mango(Mangifera indica L.), Gold Sritong and Green T4 were stored at 13 deg C and 20 deg C, with various wrapping materials to determine post harvest shelf life and suitable wrapping material. The rate of respiration ethylene production, and weight loss were significantly decreased at 13degC storage as compared with those at 20 deg C. Regardless of strain and temperature, the lowest rate of respiration and weight loss were observed for the fruit wrapped with ethylene absorbing bag(EAB)and polyethylene plastic bag(PB) while the highest weight loss was found in the control fruits followed by the fruits of EABn(Ethylene absorbing bag with needle perforated holes). Chilling injury symptoms were not observed in Nam Dok Mai mango, even when stored at 13 deg C.The pH increased gradually particularly in control and EABn at 20 deg C while in storage, Brix also increased similarly for both strains. Weight loss, skin firmness and pH were highly correlated with the total shelf life and were likewise affected by storage temperature and wrapping treatments. Significant differences were not observed among the treatment with respect to Brix % and total acid content of the fruit. Regardless of storage temperature and wrapping treatment, Green T4 showed the highest respiration rate and reached the ripening stage earlier than Gold Sritong. There were different respiratory and ethylene production patterns observed in the two strains of Thai mango in the experiment. The lower the storage temperature, the lower the rate of respiration and ethylene production, resulting in prolonged shelf life especially in the EAB and PB wrapped fruits. Shelf life and fruit firmness were better at 13 deg C than at 20 deg C in all treatments.The infection of Anthracnose disease was more rapid in Green T4 than Gold Sritong stored at 20 deg C.The present research indicated that wrapping with EAB and PB kept the Gold Sritong fruits in good condition up to 28 days at 13 deg C as evidenced by the lowest weight loss, lowest respiration rate, firmer flesh and longer shelf life with good quality while Green T4 fruit could only be stored up to 15 days Nam Dok Mai may be stored for 10 days without wrapping even at 20 deg C regardless of strains. Therefore, mango fruit wrapped with EAB and FB may offer practical means of prolonging shelf life up to 14 days longer at 13 deg C and 2 days longer at 20 deg C, depending on the strain or cultivar.