Freeze dryer system
Freeze dryer system (also known as lyophilization) is a water removal process typically used to preserve perishable materials, with the goal of extending their shelf life and/or preparing them for transport. Freeze dryer system works by freezing the material, then reducing the pressure and adding heat to allow the frozen water in the material to change directly to a vapor (sublimate).
Freezing is the most critical phase of freeze dryer system, and there are many methods for it. Freezing can be done in a freezer, a freezer or on a shelf in the freeze dryer system. Cooling the material below its triple point ensures that sublimation, rather than melting, will occur. This preserves its physical form. Freeze dryer system’s second phase is sublimation, in which the pressure is lowered and heat is added to the material for the water to sublimate. The vacuum speeds sublimation. The cold condenser provides a surface for the water vapor to adhere and solidify. The condenser also protects the vacuum pump from the water vapor.
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 dryer system retains nutritional value better than other drying methods, further supporting consumers’ desire for nutrition from whole foods. The freeze dryer systems process also preserves the actual color and shape of the original raw material, reassuring consumers they are 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.