Chiang Mai Journal of Science

The polyamine content and chilling injury (CI) of ‘Nam Dok Mai’ mango fruits harvested at different maturity stages were determined following vapor heat treatment (VHT). Both mature and immature fruits were exposed to VHT until the temperature of the inner mesocarp reached 47°C for 10 minutes. Thereafter, different treatment groups were kept at 5, 8 and 13°C. At weekly intervals, fruits were transferred to 25°C to accelerate ripening. CI symptoms and polyamine content were compared among heat-treated and non-heat-treated fruits. CI was observed in fruits stored at 5 and 8^oC. Sensitivity to CI was greater in immature fruits than in mature ones. VHT prior to cold storage consistently reduced CI in fruits of both maturity stages. VHT-fruit showed an increase in putrescine (Put) when kept at 5 and 8^oC and a decrease in putrescine level when CI was investigated. A possibility that the accumulation of Put may be associated with reduction of CI in VHT-fruit is discussed.