History of Canning Process

History of Canning Process
In the early nineteenth century, when France and Britain were at war with each other more soldiers and sailors died from disease than from battle.

Both the French and Britain government realized something important. Finding a new way to preserve food (keep it from spoilage) would prevent soldiers and sailors from dying. A larger, healthier fighting force would bring a greater advantage in battle. In 1795, the French government took action. It offered a prize of 12,000 francs. The money would go to the inventor of the best preserved food. The food had to be healthy, easily carried and not too expensive.

In 1803 a French chef named Nicolas Appert invented a new technique for preserving food. He prepared and preserved soup, beef with gravy, beans and peas. The French navy stored it for three months. Then they tried it. The food was delicious and safe to eat.

For the next few years, Appert provided the French fleet with preserved foods such as stew, milk and juice. This preservation technique proved successful. In 1810 the French government gave Appert the prize.

In this process, Appert filled the glass bottles with food and closed the bottles with cork stoppers. He then tight down the stoppers with the wire and sealed them with a thick, waxy coating called pitch. As a final step, Appert boiled the sealed bottles in water. Food heated in the airtight bottles did not spoil.

In 1821 an Englishman named William Underwood brought Appert’s invention to the United States. Underwood set up a factory in Boston, Massachusetts, to bottle lobster and salmon. Later the factory switched from glass bottles to metal canister. The word “can” was first used in Boston for these metal containers. Appert’s preservation method became known as “canning’ whether bottles or cans were used.
History of Canning Process

Principle of Food Preservation

Principle of Food Preservation
The basic principles of food preservation primary involves the process of inhibiting

• The growth and activity of microorganism

• Activity of endogenous enzymes

• Chemical reactions which may deteriorate the quality of food

• Invasion and spoilage by insects and rodents

In addition, spoilage of food may be caused during mechanical handling, processing, packaging, storing and transportation. Appropriate care has to be exercised to prevent deterioration of quality of food.

Several methods are available for preservation of food based on the above principles, the method include:

• Preventing the accessibility of food to microorganism by asepsis and packaging

• Physical removal of microorganisms from food by filtration or centrifugation

• Hindering the growth and activity of microorganism by use of preservatives, use of low temperatures atmospheric control in packaging and storing of foods and decreasing water activity in foods by drying or evaporation

• Killing the microorganism by use of high temperature and ionizing radiation

• Inactivation of endogenous enzymes by moderate heating

• Inhibition of chemical reaction through the use of chemical additives

• Fermentation of foods to yield more stable or less perishable food product

Food preservation as it is practiced in the industry always involves the use of combination of methods for achieving maximum effectiveness.

Asepsis or preventing the accessibility of food to microorganisms is well exemplified in nature, the protective covering in natural foods such as skins on fruits and vegetables, shells on eggs and nuts and skins and membranes on livestock and fish prevent the attack by microorganisms and maintain the living tissues in healthy condition.

Microbial attack is facilitated only after the death of the animal or when the skin is physically damaged. Packaging of foods and food products in a variety of materials such as metal cans, plastic films pouches, bags or boxes, paper bags or cartons and glass bottles provide effective protection against microbial attack.

Filtration or centrifugation is adopted to physically remove microorganisms particularly in liquid foods such as milk, soft drinks, fruits juices and alcoholic beverages such as wine and beer.
Principle of Food Preservation

Blanching Food to Freeze

Blanching Food to Freeze
Freezing food is probably the easiest way to keep it, but it still takes some work. For the most part, you'll want to prepare the food to go from freezer to stove or microwave to the table without much work, so do the sorting, cleaning, chopping, slicing and/or saucing and other preparatory work, before you freeze it. Food can be frozen whole, of course, or in large pieces, like a half a large zucchini frozen with the intention of stuffing it before it's cooked.

Lettuce, green onions, cucumbers, radishes and most other salad types of vegetables do not freeze well. Root vegetables like potatoes can be frozen partly cooked, but don't freeze them raw. To freeze potatoes, slice, dice or prepare as for hashbrowns or french fries. Spread them on a lightly greased cookie sheet and bake at 400 for about half the time it would take to bake through at your elevation.

Cool and package.
Many vegetables need to be blanched to stop the ripening process before they're frozen. Food that can be frozen without blanching or other treatment include peppers, celery, mature onions, tomatoes and most herbs.

Blanching is simply putting food into briskly boiling water for a specified amount of time. The easiest way to blanch food is in a pot with a wire basket, but you can dip it out with a slotted spoon, or pour it out into a colander when the time is up. If you're processing several batches of the same food, dipping it out or using a basket to lift it out makes more sense because you can reuse the same water several times over.

Use a large pot and fill it 2/3 full of water and put it on to boil. The water should be boiling briskly when you put the food in and it should come back to a boil in about a minute. After it comes back to a boil, start counting time. If it takes longer than that, either the water wasn't as hot as it should have been or too much food was put into the pot.

The denser the food, the longer blanching time it takes. Be sure to follow the directions for each food.

When time is up, remove the food from the boiling water, and cool quickly by either running cool tap water over it or dipping it in ice water. This stops the cooking process and allows the food to freeze faster. As soon as it's cool enough to handle, package it and put it in the freezer.
Blanching Food to Freeze

Food Irradiation

Food Irradiation
To many consumers, the term irradiated food conjures up visions of radioactive fallout. In truth, irradiation used on approved food does not produce radioactive food but does enhance food safety by reducing or eliminating pathogens, controlling insects or killing parasites.

Irradiation does not use heat and so is sometimes referred to as “cold pasteurization.” Bacteria, mold, fungi, and insects are destroyed as the food moves through a radiant energy field. A small amount of new compounds are formed that are similar to the changes seen in food as it is cooked, pasteurized, frozen, or otherwise prepared. Except for a slight decrease in thiamin, the nutrient content is essentially unchanged. Because irradiation kills any living cells that may be contained in the food, such as in seeds or potatoes, shelf life may be prolonged. For instance, irradiated potatoes do not sprout during storage. However, irradiation does not hide spoilage or eliminate the need for safe food handling; irradiated food can still become contaminated through cross –contamination.

Irradiation is the most extensively studied food processing technique available in the world and is used by 37 countries on more than 40 foods. In well controlled animal and human studies, no adverse health effects have been identified from irradiation. Federal law requires irradiated food to be labeled with the international symbol and state “Treated with irradiation” or “Treated by irradiation.” Research on irradiation as a part of an overall system of ensuring food safety is ongoing.
Food Irradiation

Food Preservation by Canning

Food Preservation by Canning
Using high temperatures to kill microorganisms in food is one of the principal processes implemented on the preservation of food. The canning industry uses this method most extensively.

Acidity greatly reduces the time and temperature necessary to preserve foods by heat, even though that may contain resistant spores. High acid food such as grapes, pineapples, oranges and tomatoes, for examples, require only a few minutes at 100 degree C to preserve them; foods with acidity, such as spinach, corn, carrots, and beans, require much longer periods at high temperature – depending on the solidity, size of the packages and the amount of preheating.

There are three primary thermal processing methods used today; the conventional retort, the hot-fill and the high temperature short time methods (HTST).

The conventional retort method includes filling the can with the food product, heating the can sufficiently to kill microorganisms, sealing and slowly cooling the can. Whether the slow cooling period damages the food, whether the food is overcooked, and the type of food to be preserved must all be considered when this method is chosen.

The hot fill method is used primarily for high acid foods. Then a comparatively low temperature is sufficient to reduce the microbial; population to an insignificant level due to the pH level of these foods. The food is simply heated near boiling in a method similar to pasteurization poured into a sterile can while hot, and sealed.

Another commonly used method in the heat processing of food is the HTST method. Here the food is poured into the can and exposed to a high temperature for a comparatively brief time. Sealing is accomplished at the maximum temperatures, followed by rapid cooling. This rapid cooling, usually by immersion in cold water, prevents physical damage and over cooking of the product. One major problem with this process is that any microscopic leaks in the can allow the partial vacuum caused by the contraction of cooling to draw any microorganisms in the cooling water into the can.
Food Preservation by Canning

Fortification, Restoration and Enrichment of Foods

Fortification, Restoration and Enrichment of Foods
Nutrient may be added to foods by restoration or fortification. Restoration is the replacement of nutrients lost during processing to levels similar to those present in the original products.

It can be used to help prevent nutritional inadequacies in certain segments of the population.

Fortification in the addition to food of nutrients which were, originally not present in the food or which were present in nutritionally insignificant amounts.

It can be used to help correct nutritional deficiencies in specific population segments.

Enrichment, a term often used interchangeably with fortification, is the addition of nutrients to achieve concentration specified in standards of identity.
Fortification, Restoration and Enrichment of Foods