Effect of starch edible coating on drying characteristics and antioxidant properties of papaya

The aim of the study was to investigate the effect of potato starch coating on the drying efficiency and quality of papaya. The potato starch with different concentration of 1%, 2% and 3% and calcium gluconate salt of 0.5% w/w were applied as an edible coating before drying. The effect of coating on the retention of bioactive compounds and physical properties of papaya during hot air drying at various temperature of 50 °C, 60 °C and 70 °C were investigated. The rehydration ratio and shrinkage percentage of the edible coated dried papaya slices were reduced whereas the moisture content, water activity and hardness were increased with the increasing of the concentration of edible coating. The edible coating retains the color loss during drying. The drying behavior of all the coated samples was best described by Midilli-Kucuk model, whereas the control samples followed the Page model with higher R2 and lower RMSE values. The retention percentage of antioxidants were increased by increasing the concentration of the potato starch coating, but the higher air-drying temperature reduced the antioxidants significantly (p ≤ 0.05).