Assessing the peel colour behaviour of mango 'Nam Dok Mai See Thong' during cool storage

Mango 'Nam Dok Mai See Thong' recently became the number-one exported mango of Thailand. It has an attractive appearance, with a golden-yellow peel colour at harvest and slight colour development during ripening. Its peel colour could possibly be used as an indicator for ripeness. Assessing the behaviour of peel colour during storage is the main objective of this research. Mangoes were kept at cool temperature (13°C) for 2 weeks prior moving to ambient temperature in Thailand (28°C). The data set was separated into two groups for non-destructive and destructive tests. In the non-destructive set, peel colour of 108 fruits was measured repeatedly until the quality became unacceptable. In the destructive set, 60 fruits were sampled at random to measure the peel colour and other quality attributes, each time on different fruit. Mangoes from two growing locations were compared. The results showed that peel colour (L∗, a∗, b∗ and Hue) developed gradually during cool storage, but changed drastically after relocation to higher temperatures. The L∗ a∗ and b∗ values and hue angle behaved according to a logistic function. a∗ and b∗ showed an increase, L∗ and hue a decrease. The variation is clearly high at the beginning and decreased gradually during the storage period. Fruit from both the non-destructive and destructive sets showed similar behaviour during storage. The obtained results allow prediction of the behaviour of peel colour during cool storage.