Degradation Kinetics of Colour and Total Carotenoids in Jackfruit (Artocarpus heterophyllus) Bulb Slices During Hot Air Drying

摘要

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.