The difference between freeze drying and oven drying
The difference between freeze-drying and oven drying is as follows:
Working principle: Freeze-drying is the sublimation of water, which changes the moisture in the food directly from solid to gaseous state; drying is the evaporation of water, that is, the moisture is changed from liquid to gaseous state.
Food quality and nutritional content: Freeze-drying can better retain the nutritional content and taste of food, while drying may destroy the nutritional content of food due to high temperature, making the food taste worse.
Color: The color of freeze-dried fruits is brighter, while the color of oven-dried fruits is darker.
Shape: The shape of freeze-dried fruits changes little, while the shape of drying fruits will shrink a little.
Drying temperature and time: When freeze-drying, the ingredients are first frozen, and then sublimated and dehydrated, the temperature is low and the time is short; when drying, the ingredients are placed in a high-temperature environment, and the water is evaporated through heating, the temperature is higher and the time is longer.
Scope of application: Freeze-drying is suitable for ingredients that need to ensure taste and nutritional content; drying is suitable for some high-temperature-resistant ingredients.
Manufacturing cost: Freeze-drying requires the use of specialized refrigeration equipment and vacuum drying equipment, which is costly; drying costs are relatively low.
