Freeze drying is an incredibly healthy and effective dehydration process you can use to preserve high quality foods. This dehydration process has a rich ancient story that we believe that our beloved customers or readers would be interested in learning. Enjoy reading about the fascinating evolution of freeze dried food!
The History of Freeze Dried Food
Freeze drying was invented by Jacques-Arsene d’Arsonval at the College de France in Paris in 1906. During World War II, freeze drying was widely used to preserve blood serum. Since then, freeze drying food has emerged as one of the most vital food preservation processes for heat-sensitive biological materials. During the 1950s, industrial freeze-drying of foods became popular. Freeze drying is currently used as a preservation method for foods such as ready to eat camping food, pharmaceuticals, and a large range of other products.
Freeze Dried Food In Today’s Food Market
The global freeze-dried product market is valued at £34.15 billion in 2016 and is expected to grow at a compound annual growth rate of 7.01% during the forecast period. Freeze-dried food is the best dehydrated food, due to its superior texture and sensory quality after rehydration.
Primary factor driving the freeze dried food market is the exceptional quality of freeze dried food products when compared to other drying technology products. Other factors contributing to the global freeze-dried food market are the expanding preserved food market, growing urbanization, and the convenience to the customer. The final product has an excellent shelf-life (up to 25 years) without any added preservative.
Increased shelf-life makes it a profitable product during its supply chain. Moreover, the ingredients retain their original shape, while being light-weight and compact, which makes freeze dried food brilliantly convenient for transportation. In the developed regions such as North America and Europe, the application of freeze dried ingredients in healthy snack items is growing at a fast rate which is another major driver for the market.
Technological advances in freeze-dried products, to explore super foods such as beetroot and elderberry, is the future spotlight of the market. The growing demand for additive-free and natural products is providing a good opportunity for the freeze dried food market. In the developing regions, there is a growing demand for traditional products such as miso soup in Japan, and instant foods.
The Science Behind Freeze Dried Food
Lyophilization is the technical term for freeze-drying. Freeze drying is the process by which the solvent (usually water) and/or suspension medium is crystallized at low temperature and removed by sublimation. Sublimation is the direct transition of water from solid state to gaseous state without melting.
There are generally three stages in the freeze drying process: freezing, sublimation drying, and desorption drying. The freezing phase is the most important stage in the freeze drying process. It’s critical to freeze foods rapidly in order to avoid the formation of large ice crystals, which deteriorate the final product quality. During the primary drying phase, the pressure is lowered through the application of a high vacuum, and heat is applied to provide the energy needed for the ice to sublime. This initial drying phase removes about 95% of the water present in the food. This slow step can take anywhere from several hours to two days. Application of too much heat during this phase could result in a loss in final product quality.
Another component of the primary drying process is condensation of the sublimed water vapor. Sublimation accounts for about 45% of the total energy consumption for the process, while application of vacuum and condensation each represent about 25% of the total energy consumption. A secondary drying phase is then needed to remove unfrozen water molecules remaining after primary drying. During this phase, the temperature is raised higher than in the primary drying phase in order to vaporize the water molecules. Pressure is frequently lowered during this phase, but not in all cases.
The final freeze-dried food typically contains between 1% and 4% moisture. Final food products are nitrogen sealed and packed in polybags or cans. They can be stored between 6 months and 3 years in polybags and 25 years or longer in cans.
Freeze- dried foods offer superior quality compared to food dehydrated by other methods. The high quality is due to the absence of a liquid phase, as well as the low temperature of the process. Freeze drying preserves flavor, color, and appearance, while minimizing thermal damage to heat-sensitive nutrients. In addition, the texture is well preserved due to the process occurring in solid state. Freeze-dried products are typically crisper and have rehydration ratios four to six times higher than conventional air-dried foods. Other key benefits of freeze drying include the high recovery of volatiles, retention of structure and surface area, high yield, long shelf life, and reduced weight for storage, shipping, and handling.
Now that you know the key benefits of freeze dried food, it’s time to shop for freeze dried food for your next camping trip! Shop at our online freeze dried food store and have the freeze dried meals delivered right to your doorstep!