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The kinetics of colour and carotenoids degradation in jackfruit bulb slices was evaluated during hot air drying at 50, 60 and 70°C. Visual colour as well as total carotenoids (TC) content was found to be influenced by the drying process. Tri-stimulus colour parameters such as Hunter L and b values decreased and a value increased during drying. The combination of Hunter L×b value was found to represent the colour change adequately. Degradation of TC and visual colour in terms of Hunter L×b value followed first-order reaction kinetics; however, zero-order reaction kinetics was found adequate to describe changes in total colour difference (TCD) and non-enzymatic browning (NEB). Dependence of the rate constant followed the Arrhenius relationship. The process activation energies (E a ) for Hunter L×b value, TCD, NEB and TC were 29.96, 27.21, 27.48 and 55.61 kJ/mol, respectively. Higher E a for TC content indicated greater temperature sensitivity as compared with other colour parameters. Relationship of TC content and Hunter L×b value was found to be more consistent through regression analysis with R 2 ≥0.979. NomenclatureA Absorbance at 420 nm at drying time t A o Initial absorbance at 420 nm C Value of total carotenoids content at drying time t C o Initial value of total carotenoids content E a Activation energy H Value of visual colour in terms of hunter L×b value or total color difference at drying time t H o

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