Effects of air-impingement jet drying on drying kinetics and quality retention of tomato slices

The purpose was to explore the drying kinetics, the moisture effective diffusivities, color, total polyphenols, lycopene and antioxidant activities of dried tomato slices by air-impingement jet drying (AIJD). The results showed that high temperature increased the drying rate, and Modified Page model accurately predicted the AIJD characteristics of tomato slices. AIJD is better than hot air drying in shortening drying time, enhancing drying rate and decreasing the loss of total polyphenols, lycopene and antioxidant capacity of tomato slices. Tomato slices dried by AIJD also showed higher lightness and redness. Lycopene content and antioxidant activity of tomato slices dried by AIJD were increased by higher drying temperature. Based on experimental data, AIJD at 80 degrees C can be used in tomato drying process due to the advantages in drying efficiency and content of bioactive compounds. This study will provide helpful information for the production of high quality of dried tomato products.