Experimental investigation of vitamin C yield of tomatoes and vitamin C essence by spray drying and dehumidifying the drying air: Product quality and energy consumption

Spray drying is a method of preservation that is widely used in food and pharmaceutical industries. Nevertheless, the drying temperature in spray drying is the common problems faced during the drying process. Drying in high temperature inevitably caused damages to the material, especially for heat-sensitive material including vitamin C. Vitamin C is more sensitive than other vitamins. In tomatoes, it may be browning due to high temperature in drying process. To get around this, the spray dryer is then combined with a dehumidifier system. The aim of this study is to know the safe drying temperature and also to know the specific energy consumption when using a combination system. Testing was performed using vitamin C from tomatoes and vitamin C essence. Based on research result, the temperature of drying air is not recommended to exceed 90°C, because the vitamin C content will be degraded at that temperature. The lowest ratio of specific energy consumption (RSEC) when the drying air temperature at 90 °C is obtained at the highest drying air flow rate with the lowest drying air specific humidity with a value of 0.45.