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Why freeze dried food is more and more popular now?
What the features or advantages of freeze dried food?
Why so many food industry or pharmaceutical industry trust freeze drying process?
What’s the freeze dried food?
Freeze dried
food means: the moisture of food sublimate from solid phase to gas phase directly, make food dehydrate and drying, finally become dried food/ fruit / vegetables,etc. These are named as freeze dried food. -
1. Features of freeze dried food freeze dried fruit & vegetables:
1) Freeze dried food keep the nutrient content, color, smell and taste of fresh food at the maximum degree. Freeze dried food is drying under low temperature and vacuum condition, decrease the loss of some thermo sensitivity and easy oxidation material, maximum keep all kinds nutrient content of food.
2) Freeze dried food will not loss the original skeleton structure of food, keep the food original form.
3) Dehydration performance is good, more close to fresh food quality.
4) No surface harden problem with common drying method.
5) Easy for storage and transport.
2. Range of freeze dried food freeze dried fruit & vegetables:
Each kind of food all could be freeze dried, but as the production cost of freeze dried food is expensive, so now freeze drying process is mainly used for luxury food, let’s see the below freeze dried food classification together:
1) Freeze dried fruit & Freeze dried vegetables: freeze dried strawberries, vacuum freeze dried jackfruit, pineapple, apple, juicy peach, tomato, carrot, green onion, garlic, etc.
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2) Freeze dried meat / poultry products: pork, beef, chicken, rabbit meat, etc.
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3) Freeze dried aquatic product / marine product: shrimp, fish, trepang, dried scallop, kelp, laminaria japonica, nori, etc.
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4) Freeze dried seasoning: jam, soup bases, regulate material, spice, etc.
5) Freeze dried convenient food and others: space navigation food, military food, tourist food, tea, coffee, etc.
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3. Production process of freeze dried food freeze dried fruit & vegetables:
1) Pretreatment
A. Fruit and vegetables pretreatment is same as freeze food.
B. Meat food pretreatment.
C. Liquid phase / Paste food pretreatment contains sterilization, concentration, pelletize, add antioxidant and anti-caking agent etc, process.
2) Pre-freezing
Freezing speed will effect the quality and drying time of freeze dried food. If freezing speed is fast, the ice crystal which produced in food will be small and distribute uniform, food damage is little, after freeze drying could keep food original organization structure and performance. But as small ice crystal left small hole after sublimation, the vapour discharge path is straitness, resistance is big, so food freeze drying speed will be slowing.
Choose one most suitable freezing speed will help you achieve top quality freeze dried food and minimum energy expenditure.
3) Sublimation drying
A. Freeze dryer’s loading capacity and wet weight loading capacity are the important factors for drying time.
B. Drying temperature, temperature control principle is to avoid ice crystal melting in freeze dried food.
4. The production equipment of freeze dried food freeze dried fruit & vegetables:
1㎡ ~5㎡ small type food freeze drying equipment
, also named in-situ vacuum freeze dryer, most use in-situ contact type drying method. -
Over 10㎡ industrial vaccum freeze dryer
, most use radiate separation type freeze drying method, drying chamber and subzero storage usually use rail or trolley to contact. -
5. The effect of freeze drying for food quality and nutrient content：
1) Storage period
Most of moisture of freeze dried food is dehydrated, ordinary moisture content is between 1.0% ~ 2.0%. Under normal temperature, freeze dried food could store 2 years, if use ferric jar to package, could store longer time.
2) Special flavour
The volatility aroma ingredient of food loss much more little than using hot air drying process. Mincing food will loss more volatility aroma ingredient than the food which has keep a certain tissue thickness when freeze drying.
3) Color
Product has small oxygen influence, all kinds of ski reaction will not happen, so will not occur the phenomenons such as food brown stain and color fading. During freeze drying, food may occur non-enzymatic browning, brown stain speed is decided by the drying temperature and the moisture left in food.
In general, the color of freeze dried food is much better than other drying process.
4) Volume and weight
Dehydration appears as cellular structure, the superficial area of tissue enlarge about 100-150 times than original. So freeze dried food volume and weight is very small, most is less than 1.
5) Mouthfeel
As original structure of food has some change after freeze drying, so mouthfeel also has some change, VC is about at 10%~50%, B1 is at 30%,etc.
Why freeze dried food is more and more popular now?
What the features or advantages of freeze dried food?
Why so many food industry or pharmaceutical industry choose freeze drying process?
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TOPTION as professional lab solution provider who has more than 10 years development in freeze dryer industry, ISO & CE certification, provide customization of kinds of vacuum freeze dryer
, learn more please contact TOPTION specialist directly: [email protected]
