freeze-drying
Quick Summary
Freeze-drying is a process used to preserve materials, most commonly food, by drying them in a frozen state under a high vacuum. This method involves lowering the temperature of the substance below its freezing point, causing the water within it to turn into ice. The vacuum then allows this ice to sublimate directly into vapor, effectively removing moisture while the item remains frozen.12
This technique is highly effective for preservation because it significantly inhibits the growth of microorganisms and slows down chemical reactions that lead to spoilage. While freezing itself is a long-standing method of food preservation, freeze-drying offers a way to remove water without the high temperatures that can degrade certain food qualities. The apparatus used for this process is called a freeze dryer. Freeze-drying is also utilized in various industrial applications beyond food, such as in medicine and research.2345
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advanced ceramicsCoprecipitation and freeze-dryingOften the salt compounds of two desired precursors can be dissolved in aqueous solutions and subsequently precipitated from solution by pH adjustment. This process is referred to as coprecipitation. With care, the resulting powders are intimate and reactive mixtures of the desired salts. In…
Read MoreOften the salt compounds of two desired precursors can be dissolved in aqueous solutions and subsequently precipitated from solution by pH adjustment. This process is referred to as coprecipitation. With care, the resulting powders are intimate and reactive mixtures of the desired salts. In…
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Andean peoplesEconomic systems…Andean peoples developed preserves of freeze-dried meat, fish, and mealy tubers (charki, chuñu) that kept indefinitely and weighed much less than the original food. The giant warehouses that lined the Inca highways could be filled with these preserves and used to feed the engineers planning cities and irrigation canals, the…
Read More…Andean peoples developed preserves of freeze-dried meat, fish, and mealy tubers (charki, chuñu) that kept indefinitely and weighed much less than the original food. The giant warehouses that lined the Inca highways could be filled with these preserves and used to feed the engineers planning cities and irrigation canals, the…
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proteinThe isolation and determination of proteins…in a dry state by freeze-drying (lyophilization), in which the protein solution is deep-frozen by lowering the temperature below −15 °C (5 °F) and removing the water; the protein is obtained as a dry powder.
Read More…in a dry state by freeze-drying (lyophilization), in which the protein solution is deep-frozen by lowering the temperature below −15 °C (5 °F) and removing the water; the protein is obtained as a dry powder.
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- dehydration
Freeze-drying benefits heat-sensitive products by dehydrating in the frozen state without intermediate thaw. Freeze-drying of meat yields a product of excellent stability, which on rehydration closely resembles fresh meat.
Read MoreFreeze-drying benefits heat-sensitive products by dehydrating in the frozen state without intermediate thaw. Freeze-drying of meat yields a product of excellent stability, which on rehydration closely resembles fresh meat.
Read More - food preservationDehydration
A related technique, freeze-drying, employs high vacuum conditions, permitting establishment of specific temperature and pressure conditions. The raw food is frozen, and the low pressure conditions cause the ice in the food to sublimate directly into vapour (i.e., it does not transit through the liquid state). Adequate control…
Read MoreA related technique, freeze-drying, employs high vacuum conditions, permitting establishment of specific temperature and pressure conditions. The raw food is frozen, and the low pressure conditions cause the ice in the food to sublimate directly into vapour (i.e., it does not transit through the liquid state). Adequate control…
Read More 
fish processingDrying…drying, vacuum drying, or vacuum freeze-drying. Each of these methods involves adding heat to aid in the removal of water from the fish product. During the initial stages of drying, known as the constant-rate period, water is evaporated from the surface of the product and the temperature of the product…
Read More…drying, vacuum drying, or vacuum freeze-drying. Each of these methods involves adding heat to aid in the removal of water from the fish product. During the initial stages of drying, known as the constant-rate period, water is evaporated from the surface of the product and the temperature of the product…
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fruit processingDehydration…for raisins; hot-air dehydration; and freeze-drying.
Read More…for raisins; hot-air dehydration; and freeze-drying.
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dairy productIce cream manufactureFreeze-drying eliminates the need for refrigeration and provides a high-energy food for hikers and campers and a “filling” center for candy and other confections.
Read MoreFreeze-drying eliminates the need for refrigeration and provides a high-energy food for hikers and campers and a “filling” center for candy and other confections.
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meat…decay are refrigerating, freezing, curing, freeze-drying, and canning.
Read More…decay are refrigerating, freezing, curing, freeze-drying, and canning.
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vegetable processingDehydration…drum drying, spray drying, and freeze-drying. Although freeze-drying produces a food of outstanding quality, the cost is high, and it has not been used widely in vegetable products.
Read More…drum drying, spray drying, and freeze-drying. Although freeze-drying produces a food of outstanding quality, the cost is high, and it has not been used widely in vegetable products.
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