Dehydrated tomato powder high nutritional value

Drying method of food grade tomato powder edit voice
(1) Freeze drying method
Dehydrated tomato powder
The method is to freeze the tomato concentrate at low temperature, and then sublime the moisture in a high vacuum state for drying. The resulting tomatoes still retain their original structure without compromising its original shape and size. Therefore, the freeze-dried particles have a porous structure and retain the space originally occupied by moisture without collapsing, thereby facilitating the rapid rehydration of the product. However, this method consumes a lot of energy, and the freeze-drying equipment is very expensive, so the cost of the product obtained is high.
(2) Puffing drying method
The puffing drying method uses puffing drying equipment to dry the tomato concentrate. An absolute pressure of 2.6 mmHg is usually required for dehydration, and the temperature of tomato concentrate is usually 60-70°C. In order to make the moisture content of the final product reach 3%, the drying time is usually 90 minutes to 5 hours. The product should be cooled down before removing the vacuum to avoid the product’s bulky structure from collapsing. This is because the tomato powder obtained is thermoplastic; the tomato powder prepared by this method has a relatively hard structure and the volume is similar to the volume of the concentrate. The product is complex. Poor water performance. In addition, expansion must be carried out under vacuum conditions, and the cost is relatively high, resulting in relatively expensive products.
(3) Spray drying method
Before spray drying, the concentrated tomato slurry should be homogenized. The homogenization pressure is generally 150 to 200 kg/cm². Generally, a centrifugal or two-fluid spray dryer with a cooling jacket on the tower wall (double-layer tower wall, the temperature of the inner wall can be cooled by air) is used for drying; if the heating medium is pre-dehumidified dry air, Then the inlet air temperature during drying is generally about 150-160°C, the outlet air temperature is 77-85°C, and the feed concentration is generally 20%-30%.
There are already some modified spray drying equipment on the market that can be used to process fruit and Vegetables Powder. Some use air as the drying gas, and use the medium inlet temperature of 75-95℃ for drying, which can increase the production speed; others use the dehydrated air as the drying gas, which can be used at a lower inlet temperature (25-50 °C) for drying. However, the towers of all these spray drying equipment used to dryhigh quality tomato powderare very high, which increases the cost of setting up the factory.