Vacuum Drying of Cooking Tomato

Abstract

Vacuum drying characteristics (changes of mass, volume and drying surface area) of cooking tomatoes at five temperatures ranging from 20°C to 60°C and subsequently the color and the ingredient change (lycopene content) were measured. As results, the relationships between both the volume and the drying surface area and moisture content were linear and the drying rate was constant from the initial moisture content to about 250% (d. b.). Therefore, it was estimated that the vacuum drying of cooking tomatoes was in the constant rate period from the initial moisture content to about 250% (d. b.). The lycopene content in cooking tomatoes decreased in the vacuum drying process. As this reason, the possibility of the enzymatic oxidation was considered.