Effect of basil and chitosan coating on drying kinetic, color, texture and antioxidant activity of apple slices: hot air oven and vacuum drying

The use of edible coatings can help reduce the undesired effects caused by the drying process of fruits and vegetables. In this study, the influence of two different edible coatings including basil and chitosan (0, 0.5 and 1 %) on drying kinetic, color, texture and antioxidant activity of apple slices were evaluated at different temperatures (40, 50 and 60 ˚C) in hot air oven and vacuum drying. The results showed that the use of different coatings in both drying methods increased the drying time. Fitting of different mathematical models on the experimental data showed that the Midili model for basil coatings and the approximation of diffusion model for chitosan coatings are able to predict the moisture content more accurately than other models. With increasing coating concentration or decreasing drying temperature the lightness, adhesiveness, cohesiveness and antioxidant activity enhanced. But, the redness, yellowness, brownness, total color difference and hardness diminished. Generally, basil and chitosan coating pretreatment could be considered as an effective approach to improve the quality of the dried apple fruit in drying industry.