Freeze drying system
Freeze drying system, also known as lyophilization, is a low temperature dehydration process that involves freezing the product, lowering pressure, then removing the ice by sublimation. This is in contrast to dehydration by most conventional methods that evaporate water using heat. Because of the low temperature used in freeze drying processing, the quality of the rehydrated product is excellent. In case solid objects like strawberries are freeze dried the original shape of the product is maintained. If the product to be dried is a liquid, like often seen in pharmaceutical applications, the instant properties of the final product are optimized by the combination of excipients (i.e., inactive ingredients). Primary applications of freeze drying system include biological (e.g., bacteria and yeasts), biomedical (e.g., surgical transplants), food processing (e.g., coffee) and preservation.
Freeze drying system, or lyophilization, removes moisture from raw, frozen product through a vacuum system and process called sublimation. Frozen raw product is cut down to the desired piece size and spread evenly onto trays that are stacked and stored in freezers. The sized product freezes at an even colder temperature, reaching an optimal state at which the original shape of the product can be retained. The trays are then loaded into a refrigerated freeze-drying chamber that seals tightly shut. The chamber’s vacuum system removes ice from the product and converts it directly to a vapor without moving through the liquid state, in a process called sublimation. Since the water is removed from the product in a frozen state, cell structure remains intact and finished product bears close resemblance to its fresh counterpart, thus retaining its piece identity.
Freeze drying system retains nutritional value better than other drying methods, further supporting consumers’ desire for nutrition from whole foods. The process also preserves the actual color and shape of the original raw material, reassuring consumers they are actually getting real fruits and vegetables in their diets. The intense flavor and aroma of freeze-dried ingredients also closely resembles the profile of the raw material.