With the improvement of people's demand for food quality, vacuum freeze-drying technology is also continuously applied and developed in food. Vacuum freeze-drying of food can preserve the color, aroma and taste of the food to the greatest extent while retaining the nutrition of the food to the greatest extent. At the same time, it can also prolong the storage time of the food at room temperature, which is convenient for people to use all kinds of food. Vacuum freeze-drying technology requires high technology. In order to meet people's desire for green and nutritious food, this technology should be continuously improved.
Freeze drying is one of the ways to keep substances from going bad. Freeze-drying is a new type of drying technology, that is, under low temperature conditions, the wet material is frozen, and then heated at a higher degree of accuracy to sublimate the solid ice and remove the moisture in the material. The full name is vacuum freeze-drying technology, referred to as freeze-drying technique. The food obtained by freeze-drying technology is called freeze-dried food, also called FD food.
Almost all water-containing foods can be freeze-dried, but it is difficult to freeze-dry some foods with high sugar or gum content and foods with low eutectic point temperature. Various types of food that can be freeze-dried are as follows:
1. Vegetables
Chives, garlic, onions, ginger, peppers, green peppers, carrots, spinach, cauliflower, snow peas, asparagus, beans, parsley, broccoli, mushrooms, etc.
2. Fruits
Apple, peach, pear, apricot, red date, leatherberry, banana, pineapple, cantaloupe, longan, durian, blueberry, mangosteen, etc.
3. Meat
Beef, mutton, pork, chicken, snake, etc.
4. Aquatic products
Fish fillet, shrimp, crab meat, cuttlefish shreds, squid, whitebait, sea cucumber, scallops, etc.
5. Convenience food
Instant noodles and its accessories, meatballs, soup ingredients, baby food, military food, aerospace food, etc.
6. Instant beverages
Coffee, milk, soybean milk, fruit juice, royal jelly, etc.
7. Condiments
Jams, soups, seasonings, spices, etc.
