Development of taro (Colocasia esculenta (L.) Schott) flour as an ingredient for food processing: effect of gelatinisation and drying temperature on the dehydration kinetics and colour of flour

摘要

A study was carried out to determine the dehydration kinetics of pregelled taro slices. Towards this objective 0.5 cm thick taro slices were cooked for varying periods of 0, 20, 45 and 60 min and dried in an air convection oven at varying temperatures of 50, 60, 70 or 80℃ before milling into flour. Analysis of data obtained during the monitoring of the drying process showed the dehydration process to follow a two falling rate mass transfer model. Within each falling rate period, mass transfer coefficients did not vary with moisture content. While the rate of drying was observed to increase with drying temperature, it was inversely related to the degree of gelatinisation. Drying at high temperatures affected the colour and the susceptibility to gelatinisation of the flour especially that obtained from gelatinised slices.