For example, vacuum freeze-drying (FD) and vacuum low-temperature oil bath drying (VF) are mainly used for fragile fruit and vegetable products.

1. At present, the domestic market mostly adopts low-temperature vacuum frying technology. Because of its low processing temperature and short processing time, it retains the flavor and most nutrients of the original fruits and vegetables. However, the oil content of vacuum fried fruit and vegetable chips is still above 10%, which not only increases the cost and is not easy to store, but also is harmful to human health if eaten for a long time.

Vacuum freeze-drying (FD) dehydrates it by freezing at low temperature, which is known as the food processing technology of 2 1 century. Vacuum freeze-drying technology is to keep the frozen state after freezing, and use vacuum to sublimate the ice into steam and discharge it to remove excess water in the articles. Because it is dehydrated at low temperature, it is better for food quality than VF technology.

The shape and size of the fruit are basically unchanged before and after drying, and the color, smell, characteristics and nutritional components of the original commodity or food can be retained to the maximum extent; The water content involved is low, which generally does not cause the change of water-soluble components during storage.

2. The chips processed by vacuum low-temperature oil bath drying (VF) technology will only form fragments when crushed by fingers, and the chips processed by vacuum quick-freezing drying (FD) technology will form powder when crushed by fingers, which is the easiest way to distinguish the two technologies.

3. Compared with VF, the chip processed by FD technology is more suitable for infants.

Extended data:

Compared with other drying methods, vacuum freeze-drying has obvious advantages:

(1) drying is carried out at low temperature, so it is especially suitable for heat-sensitive substances, so it will not denature or lose its vitality.

(2) When drying at low temperature, the loss of volatile components in the material is less.

(3) It is impossible to carry out microbial growth and enzyme action, and keep the original natural state.

(4) drying under vacuum condition, almost no oxygen, and easily oxidized substances are protected.

(5) the substance is dried under freezing. After drying, the volume is almost unchanged and will not shrink. This kind of substance is loose, porous and spongy, which dissolves quickly after adding water and restores to its original state almost immediately.

(6) About 90% ~ 95% of water is removed during the drying process. The dried product can be stored at room temperature for a long time.