Freeze dryers don't contribute much to the standard of fruit and vegetable transportation

Freeze dryers don't contribute much to the standard of fruit and vegetable transportation
The fruits and vegetables are freeze-dried to reduce the water content, the low temperature makes the microorganisms unable to multiply, and the enzymes in the fruits and vegetables are inert, so that the fruits and vegetables are preserved for a long time and are convenient for long-term transportation.
1. The air is boring
The mechanism of the air freezing and drying machine skill is common with the boring mechanism of other conventional materials. The main feature is to select the hot air with suitable temperature and air volume to promote the internal water dispersion of the fruit core through the capillary. Because the atmospheric pressure hot air skills are the most widely used, the skills and equipment for atmospheric hot air dry operation have been thoroughly discussed at home and abroad. For example, the domestic research and development of pepper dehydration and boring process, carrot silk, jujube, onion, shiitake mushroom hot air dry characteristics, and foreign hot convection convection computer mathematical model discussion.
During the dehydration and drying of fruits and vegetables, a series of quality changes may occur. These changes include chemical changes such as browning, lipid oxidation and fading; physical changes such as rehydration, cracking, arrangement and loss of aroma; nutrient changes,
Such as the loss of vitamins and proteins, microbial growth. In order to minimize the sensory changes in vegetables during the boring process, the temperature should be lowered as much as possible and the boring time should be shortened. During this period, the microorganisms are not really lethal; in order to ensure the safety of the fruits and vegetables, before the boring Pre-heating: In order to prevent the entry of pathogenic bacteria, it is necessary to pay special attention to hygienic conditions when selecting and pre-treating various materials. In order to effectively control the quality of the fruit-derived fruit, it is necessary to study the quality parameters and repercussions of dry products. Kinetic data for chemical changes, vitamin destruction, enzyme inactivation, and microbial lethal conditions.
2. Soaking and dehydrating
Fruit and vegetable soaking and dehydration means that at a certain temperature, the fruit or the root vegetables are immersed in the solution of the permeation pressure, that is, the sugar solution or the salt solution, and the semi-permeability of the cell membrane is used to transfer the moisture in the material to the solution to remove part of the water. a skill. Compared with the traditional hot air dehydration, since the water transfer surface does not change phase, that is, there is no need to heat, the dehydration of the dehydration has the characteristics of low energy consumption and less loss of the hundred nutrients. Because it can remove the moisture in the fruit and the swallow in a short period of time without damaging its arrangement. They are still able to maintain their original flavor, color, nutrients and quality, and the look and feel is almost the same as when it is fresh. It is therefore a good processing skill.
In production, soaking and dewatering can be used as a pre-treatment method for fruit and vegetable processing, combined with the use of fruits and vegetables, such as boring, freezing, and canning. When the fruits and vegetables that have been soaked and dehydrated are boring, the dry bath time of the product can be shortened by 10%- L5%. At the same time, because of the reduction in volume and weight, the boring payload is increased by 2-3 times, thereby greatly saving energy consumption.