FROM MOUNTAIN HOUSE'S WEBSITE:
Freeze-drying has several advantages over other food preservation methods.
Frozen foods retain fresh flavor and nutritional value, but require uniform, low temperature storage conditions. Dehydrated and canned foods are shelf-stable, but high-temperature processing can degrade flavor, texture and nutritional content. Freeze-drying combines the best of these processing methods. It preserves freshness, color and aroma similar to frozen food, while providing the shelf-stable convenience of canned or dehydrated food. Freeze-dried foods:
Taste fresh. Freeze-dried foods, like frozen, retain virtually all their fresh-food taste and nutritional content. Freeze-drying removes the water, not the flavor.
Look fresh. Freeze-dried foods maintain their original shape and texture, unlike dehydrated foods, which shrink and shrivel due to high-temperature processing. Freeze-drying removes water under low temperatures (typically a maximum of 100 to 130 degrees F), which keeps intact the moisture channels and food fibers. Just add water, and in minutes every fresh food detail returns.
Weigh less than fresh. Freeze-dried foods have 98% of their water removed. This reduces the food's weight by about 90%. Mountain House products light weight and compact so you can carry several days of food in a small backpack..
Stay fresh. Freeze-dried foods can be stored at room temperature, without deterioration or spoilage. This is because freeze-drying and packaging remove both water and oxygen - the two primary causes of food deterioration. Mountain House, backpacking products are immediately packed in a unique moisture and oxygen-barrier packaging to preserve the food's flavor, texture, color, and nutrients. To "double" ensure freshness and prevent the food from turning rancid, an oxygen scavenger packet is placed in each pouch. The oxygen scavenger consists of iron oxide, which absorbs oxygen within the pouch. This product is not harmful to your health, but is not meant to be eaten.