Freeze-dried food packaging features

1. Freeze-dried food quality characteristics The greatest quality characteristics of freeze-dried foods are through freeze-drying, including freeze-sublimation drying and vacuum freeze-drying, to maximize the moisture content of foods with high moisture content. Its quality characteristics are as follows.
(1) The shrinkage rate of freeze-dried foods is much lower than that of other dried foods, which can maintain the form of fresh foods.
(2) Freeze-dried foods have no surface hardening phenomenon, but when rehydration, moisture can quickly penetrate into the interior of freeze-dried foods, thus having excellent rehydration performance.
(3) Freeze-dried foods avoid the destruction of heat-sensitive components and the oxidation of easily oxidized components in common food processing. Therefore, the freeze-dried foods have the highest retention of nutrients and physiologically active ingredients.
(4) Freeze-dried foods are processed at a low temperature. They do not suffer from discoloration caused by pigment decomposition, browning caused by enzymes and amino acids, and can be used as a raw material without adding pigments when reconstituted. .
(5) Freeze-dried foods have a low volatility during processing, and the concentration of aromatic components after drying is relatively increased and the aroma is more concentrated.
The above quality characteristics determine the packaging characteristics of the freeze-dried food.
2. Characteristics of freeze-dried food packaging (1) Freeze-dried foods are completely dehydrated without adding any preservatives, and can be stored safely and for a longer time with proper packaging.
(2) Freeze-dried food structure is porous sponge-like. If it is improperly packaged, it will easily absorb moisture and deliquescence once it is exposed to air.
(3) The specific surface area of ​​freeze-dried foods is relatively large, and oxygen in the air is easily brought into contact with the interior of the food. Over time, the fatty acid will be rancid by oxidation, which needs to be controlled by packaging technology.
(4) The relative density of freeze-dried foods is relatively small and the volume occupied is relatively large. In addition, the porous vegetable structure is fragile and inconvenient for transportation (transportation after packaging treatment is required).
The quality characteristics and packaging characteristics mentioned above are exactly what we must consider when designing and choosing packaging methods and technologies.