Canning is a food preservation technique whereby food stuffs are processed and packaged in airtight cans. Canning allows a longer shelf life extending from a year to five years, or even more under specific conditions. Canning is a comparatively new development in the history of food preservation. In the past, food was preserved by drying, salting and even fermentation. But preserving food by heat-treating and then sealing it in airtight containers didn't come along until the late 18th century.
Food preservation prevents the growth of microorganisms as well as slowing down the oxidation process. It may also comprise of procedures that prevent visual deterioration.
The food canning process
Food canning basically involves heat treatment of foodstuffs. Heat is applied with respect to the type of food being preserved to ensure that all microorganisms present are destroyed completely. After this, the food items are sealed into airtight containers which are then passed under steam pressure of high temperatures. The conditions will differ for different foodstuffs. Processing conditions are maintained at minimum to warrant sterility, retain flavor and nutritional value. Once the cans are sealed, the food is expected to maintain its high eating quality for more than two years given the can is not tampered with in any way.
The canning process will be different for various products. Fruits and vegetables may be peeled or have branches removed. Air will also be pressed out of vegetables to improve their shelf life. Sea food will be packaged after being boned with the exception of smaller fish like sardines. Meat products are usually boiled to soften before canning.
Preservation may involve more than one food preservation method. In preserving of fruits for example, there will be boiling so as to kill bacteria and reduce moisture content, sugaring to inhibit bacterial regrowth and sealing to prevent contamination. To ensure freshness, foodstuffs are packed at their peak of freshness and most canning facilities are located near the point of harvest. Seafood canneries are found next to the docks. Meats, soups and stews are canned near or within animal slaughter houses. Little or no transportation at all keeps costs down and ensures foodstuffs are packed when the flavor is at its peak.
The Benefits of canning
Canned Food has higher Nutritional value
Food is bound to lose nutritional value as it ages. This is luckily not the case with canned food. For starters, food to be canned is harvested at its prime nutritional conditions. Research indicates that food canning improves the nutritional value of some foods. Canned foods can be just as nutritious as fresh and frozen foods because canning preserves many nutrients. The amount of minerals, fat-soluble vitamins, protein, fat and carbohydrate remain relatively unchanged by the process of canning. Many canned products actually contribute more health- promoting nutrients than cooked fresh or frozen foods.
Canning guarantees Safety
The canning process was invented to preserve food safely and for longer life span. After food is packed into a can, the can is heated to an extreme temperature which kills microorganisms. Food preservation process is normally monitored using a system called Hazard Analysis and Critical Control Point, or HACCP. A HACCP system recognizes areas of potential contamination within the food process and builds check points to ensure that the highest possible safety standards are maintained at all times. Modern processors maintain close watch on the heating process, ensuring that the canned food that reaches the market is the safest possible product for the consumer.
Canning ensures Long Shelf-Life
The advantages of canned food over fresh produce also include a longer shelf life for unopened cans. As a general rule, unopened home-canned foods have a shelf life of 1 to 1.5 years. Commercially canned foods should retain their quality until the expiration date printed on the can. For most canned goods, this date is 2-5 years from the manufacture date.
Canned food is pocket-friendly
This is the most obvious benefit of eating canned food, and a perhaps the main reason why students on a low budget eat canned vegetables and fruits regularly. The price benefit of canned food is particularly obvious during winter months when most vegetables are out of season and will have to be shipped from abroad.
Canning ensures Convenience
Fresh vegetables and fruits have a hard time beating the convenience canned foods can offer for those with busy lifestyles. Whether you're a busy parent or just an active person, keeping cannedbeans and vegetables on hand can let you quickly and spontaneously prepare soups, stews, and even salads.
Disadvantages of food canning
Increased sodium levels
Many canned foods will have high levels of sodium. The salt helps preserve the food, but can elevate blood pressure, cause you to retain water and increase calcium loss. Sodium is not always apparent. Even when salt is not indicated among the ingredients, chances are high that the product contains some sodium. Monosodium glutamate, sodium citrate and onion salt are other forms of sodium commonly added to canned foods
High sugar levels
Canned fruits will often contain heavy syrups. The added sugar makes the fruits tastier and more appealing. On the down sides, it also increases the calorie and carbohydrate count of the final product. One way to avoid this is to choose fruits canned in water or in their own juice.
There is possible nutritional loss with canning
Some fruits and vegetables will lose nutritious value when canned. According to Weight Watchers' registered dietitian Leslie Fink, removing the peel of a fruit or vegetable reduces its fiber content. Since this is a common practice in canned foods, you'll miss out on some important nutrients if you choose canned foods over fresh fruits. Vitamin C also is destroyed during the cooking and canning process. Other nutrients, including vitamin A, potassium and Lycopene, a carotenoid, survive the canning process well.
Not all foods can be canned
Many fruits and vegetables simply don't take well to being canned. Some fruits can be put into cans, but are not very popular because they simply don't taste as good as they do when they are fresh. Finding canned broccoli, bananas, apples or potatoes is difficult, if not impossible. If you want a variety of fruits and vegetables, fresh or frozen offer more varieties.
Canning may reduce or alter the taste of food
In the contest of fresh vs. canned food, most people agree that the flavor of fresh produce is unmatched. That's also why top chefs always cook with fresh produce.
While canned foods can be easy and convenient, there are factors to consider when choosing nutritious options. When purchasing canned fruit, one ought to pick varieties that are canned in water, 100 percent juice or in its own juices. Many varieties of fruit come packed in light or heavy syrup, which equates to added sugars. Choose canned vegetables without added salts, labeled “no salt added” or “low sodium.” Be mindful that cans marked “reduced sodium” are not necessarily sodium-free. Draining and rinsing canned beans and vegetables can reduce the sodium content as well.Avoid cans with dents, bulges, cracks or leaks. This may be a sign of the bacteria that causes botulism. Damage to the can may allow air to enter, creating the ideal environment for Clostridium botulinum to grow. Botulism is more common in home-made canned goods that are improperly handled and is extremely rare in commercially packaged canned goods.Canned foods can be a part of a healthy diet, but it’s important to read labels and choose accordingly.