What is Food Preservation?
Food preservation is the science of extending the shelf life of food while maintaining as much as possible of its nutritional quality and avoiding the growth of unwanted micro-organisms. There are a number of different ways of preserving foods. Some involve storage methods, some involve packaging, and some involve treating the food in particular ways prior to or during storage, either cooking it in whole or part or combining it with other foods or substances. This science has been practiced in a variety of ways for hundreds of years.
Chilling food is one way of maintaining it. Some foods do well with the temperature level that most people associate with refrigeration, while other food items are best kept frozen. Cold cellars or root cellars were historically used to keep produce, and they are still used today. In the United States, it is common to find a combination refrigerator and freezer as a standard appliance in most kitchens. Even more specialized is the hydrator tray offered in most refrigerators to control the moisture for storing fruits and vegetables, and the butter container that keeps butter and margarine slightly warmer than the rest of the refrigerator to improve its spreadability.
Storage methods that are used in food preservation include vacuum sealing, canning, and bottling. These techniques seal food in sterile bags, jars, or cans, and canning is often combined with other preservation methods, such as pickling or the making of preserves, jams, or jellies. Wrapping food carefully, for example in plastic wrap and then aluminum foil, is another deterrent to food spoilage.
Other food preparation methods besides pickling and preserving that contribute to preserving the life and quality of foods include the following:
- Drying, which can be done in the air, or using a specialized dehydration device;
- Salting or curing, which uses osmosis to draw the moisture out of meat, and is sometimes achieved with chemicals called nitrates and nitrites;
- Smoking, a drying process often used with meat and fish that uses heat to remove moisture from food but stops short of cooking it;
- Irradiation, subjecting food to ionizing radiation in, for example, the form of X-rays or gamma rays, which is a fairly new method of treating food to kill micro-organisms and insects and reduce spoilage.
Additionally, preservation can be accomplished through pasteurization, heating foodstuffs in order to effect certain micro-organisms; lactic fermentation, a preservation method somewhat like pickling that reduces the pH value; using lye as a preservative—but note that it increases alkalinity to stop micro-organisms from growing; and preservation with ethanol.
These methods can be individually applied or in some cases combined, and are chosen depending on the particular food to be preserved.
Has anyone ever tried smoking as a form of preservation? How did it go? What was involved?
I have to confess that I know very little about it, but it has always intrigued me and I am thinking of giving it a shot myself.
I really like to preserve meat by tuning it into jerky. I bought a pretty nice dehydrator a few years back and I have been experimenting with various jerky recipes ever since.
Right now my best is probably my sweet and spicy beef. But I have done a curried chicken jerky that was really good and also made some really interesting venison jerkys. There is more variation possible than you might expect. Plus, it keeps for just about forever.
When I was a kid we had a cellar that wasn't good for much other than storing things you didn't need on a regular basis. It was a scary place for me, but my mom would store all her homemade canned food there. Because it was cool and dark down there she would also store other food there to extend their shelf life.
I don't know a whole lot about canning food, but last year I made my first batch of pickles. I went to the farmers market and bought pickling cucumbers to make the pickles with.
This was really easier than I thought it would be. Once I cut up the cucumbers I put them in jars in a solution of water, vinegar and seasonings and let them sit for about 6 weeks. After this time was up, I drained them and added sugar to the mixture.
I made sweet pickles but my sister had a recipe for dill pickles that tasted really good too. Once you eat your own canned pickles, the ones you buy in the store don't taste nearly as good.
I like to use a dehydrator to preserve food. In the summer when fresh strawberries are in abundance, I will dehydrate them to use later on. They taste great mixed in with my cereal in the morning or I will use them when I make muffins.
I also will dehydrate apples in the fall when we go to the orchard. These are great to use later on in my special granola recipe. My husband also hunts deer and many times he will dehydrate the venison to make beef jerky.
My grandma likes to use canning for food preservation. Every year she has a big garden and she likes to preserve as much of this food as she can. To me this seems like an awful lot of work, but she has been doing this for as long as I can remember.
It gives her a lot of comfort and satisfaction in the middle of winter when she opens up a jar of her canned vegetables. I am sure the food she cans is much better than the canned food she would have to buy in the grocery store.
Some of her favorite foods to can are tomatoes, green beans and peaches. She even cans meat and uses it often in soups and stews.
I am Shreya. This is the best site for children to learn about food preservation. Not only children, but even big ones can learn.
@ Parmnparsley- You can also dry meat in a survival situation. Drying will only work in a well-ventilated area with lots of sunshine, but it can be a good way to manage a fresh catch that you cannot eat in one sitting.
Thinly slice fresh meat along the grain (less than half inch thick). Skewer the meat with thin sticks with the bark removed, or hang them over something like a piece of fishing line.
Cover the meat with a breathable fabric (Bandana), or watch and fan the meat, to keep the flies away. Dry until crisp like jerky.
Just try to make sure meat can dry as fast as possible.
Smoking meats and fish in wilderness survival situations is an easy way to preserve food. You can make a pit smoker with a poncho, tarp, or blanket, some hardwood, and a few sticks.
To build a smoker, dig a hole a few feet deep and start a fire with some hardwood like birch or willow. Once the fires is reduced to a smolder, lay pieces of green wood on the fire to create a good smoke.
A couple feet over the fire, hammer some sharpened sticks horizontally into the side of the hole, about six to 12 inches below the surface. Hang thin strips of meat or fish (rubbed with salt if you have it) on the sticks.
Finally, cover the pit with your poncho or tarp, leaving a small opening for the smoke to vent. Smoke for two days, continuously adding green wood or wet hardwood chips to the fire.
Meat will hold for a month and fish will hold for a couple of weeks if you smoke for two days.
This is quite an informative article, although my concern, which is the use of citric salt/acid in the preservation of baked goods, was not noted.
Post your comments