Kinetics of colour change of bamboo shoot slices during microwave drying

P>The effect of microwave power on colour change kinetics of bamboo shoot slices was investigated during microwave drying. Colour changes were quantified by tri-stimulus Hunter L (whiteness/darkness), a (redness/greenness), and b (yellowness/blueness) system. These values were also used for calculation of total colour change (Delta E), chroma, hue angle, and browning index (BI). Microwave drying as expected changed colour parameters because of browning. The values of L and b decreased, while values of a and Delta E increased during drying. Mathematical modelling of colour change kinetics indicated that L, b, chroma and BI could be defined using a first-order kinetic model, while a, Delta E and hue angle could be defined using a zero-order kinetic model. Considering together colour deterioration and quality of dried bamboo shoot slices at higher power reveals the need of process standardisation for getting good quality product.