Convenience foods are expanding rapidly in the household as well as the catering markets, but also the declaration No artificial flavor, color or preservatives have been added is becoming an increasingly appreciated quality stamp on food products and ingredients.
A freeze-dried product automatically moves into that category. Add to this the advantages of marketing a product with its original nutritive value, product shape and texture combined with quick reconstitution. Freeze-drying then becomes the logical solution to the preservation of high quality raw materials because of their consumer preference and added commercial value.
A wide range of products may advantageously be marketed in the freeze-dried shape, e.g.
- VEGETABLES: Asparagus - Beans - Cabbage - Cauliflower - Celery - Mushrooms - Onions - Peas - Parsley - Chives - Herbs
- FRUITS AND BERRIES: Bananas - Oranges - Strawberries - Peaches - Plums - Tomato and Fruit juices - Food flavors
- ANIMAL AND FISH PRODUCTS: Beef - Pork - Ham - Chicken - Cheese - Eggs - Milk - Yogurt - Cod - Lobster - Scampi - Shrimp
- PREPARED DISHES: Baby food - TV dinners - Camp and military rations
THE FREEZE-DRYING TECHNIQUE AND ITS ADVANTAGES
In brief, freeze-drying is a drying process of an already deep-frozen product under very high vacuum and at a temperature well below the freezing point.
Thereby, the ice in the frozen product is removed without passing through the fluid state, the result being that the freeze-dried product retains most of its original characteristics.
At a pressure below the triple point, for water 4.6 mm Hg, a rise in the temperature will cause a change of the ice into vapour.
The low drying temperatures and closely controlled conditions used in freeze-drying provide the following product advantages and marketing benefits:
- More original flavor
- More proteins and vitamins
- Original product shape, color and texture
- Quick and complete reconstitution
- Long shelf life with storage at ambient temperatures