Food is one of the most important things in our lives because it is a basic necessity that we need to survive. For centuries we have found ways to preserve food for storage purposes, emergency preparedness, and daily eating. Being able to preserve food, even for a short period of time, ensures that our food will not go to waste because it went bad in just a few hours. Everything from refrigerating, freezing, and canning to dehydrating and freeze drying are useful food preservation techniques.
When food is preserved one of two things is happening. Either disease-causing bacteria are being slowed down so that they do not spoil or damage the food as quickly, or the bacteria are killed off all together. Food preservation can be used to preserve food for days, weeks, months, or even years.
Refrigerating -- This is the most common way to preserve food. It is a short-term storage option, but most people buy perishable foods intending to eat them within a few days. Refrigerating can make the difference between a food spoiling in a few hours or a few weeks. The raised temperature in the refrigerator slows down bacteria so that it doesn't do damage to food as quickly.
Freezing -- This is the next most common way to preserve food. Bacteria are literally frozen and cannot damage or spoil the food. It is often used for meats that would go bad within a few days if left in the refrigerator. Freezing certain foods can greatly increase their shelf lives.
Canning -- This is another very common food preservation technique. It has been around since the early 1800s and is still used a lot today. Homeowners enjoy being able to keep food at room temperature without it going bad for long periods of time. Canned foods are boiled before being quickly sealed in cans. Boiling kills all of the bacteria. Once opened canned foods become susceptible to bacteria again, hence the "refrigerate after opening" verbiage on most canned foods.
Dehydrating -- Dehydrating is a another technique used to preserve foods. Some come dehydrated items are powdered milk, powdered soup, dried meat, and so on. Dehydrated food is popular because some items can last for an incredibly long time. Others are popular because they have become whole new products of their own, like beef jerky and dried fruits.
Freeze Drying -- Freeze drying is typically done by food storage companies, although there are ways to do it at home in your own freezer. During the process of freeze drying the majority of the food's water content is removed. Freeze dried foods are popular because they can be stored at room temperature, are extremely lightweight and compact, and retain all of their original characteristics (taste, texture, size, nutritional value) when reconstituted.
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