Influence of drying temperature on anthocyanin and moisture contents in purple waxy corn kernel using a tunnel dryer

Abstract

The effect of drying temperature on total anthocyanin and moisture contents in purple waxy corn kernel was investigated by using a tunnel dryer. The amount of anthocyanin and moisture content were studied with the relatively low drying temperature of 60–80 °C under controlling air velocity at 1.5 m/s. The experimental results reveal that moisture content in purple waxy corn kernel slightly decreases with time and the lowest moisture content obtained by using the present method is 13%wb (wet basis). The drying rate increases with increasing temperature and the highest rate is obtained at the temperature of 80 °C (0.1492% min−1). Total anthocyanin content in purple waxy corn kernel was strongly affected by the drying temperature and moisture content. The highest total anthocyanin content was obtained at the temperature of 65 °C with the moisture content of 13%wb, which is the best condition for preserving purple waxy corn kernel by using a tunnel dryer.