Canning of foods

At the same time, scientists had been experimenting with metal containers to store food. The first metal canning of food took place in New York in 1812, when a small plant successfully canned oysters, meats, fruits and vegetables in hermetically sealed containers. 

The mercury thermometer is sufficiently accurate for practical work in the determination of temperature changes in the canning of food materials if it is properly calibrated and standardized. 

Work done for the American Canners Association has shown that the amount of processing required depends largely upon the pH value. For instance, rhubarb, cherries, tomatoes, and such rather high acid foods require less processing than com, beans, etc., which have a pH value above 4.6. The greatest danger of botulism is in the canning of foods which naturally have a pH value above 4.6. 

Heating of foods may be moderate, such as pasteurizing at temperatures of 65-88 °C, intermediate, such as thermal processing (canning) at temperatures of 88-121 °C, or high, such as frying at approximately 177 °C or oil deodorizing at... 

Bacteria not only attack teeth but can also make people extremely sick. Therefore, canned food must be specially prepared to prevent the growth of bacteria. This is usually done by boiling or steaming. People who can their own food at home, however, do not have the sophisticated machines that food-canning manufacturers have. Even so, there are other methods that home canners can use to preserve their own food and keep their families safe. For example, high heat can be used to kill the bacteria Clostridium botulinum, which causes one deadly form of food poisoning called botulism. Acidic conditions will also kill C. botulinum. Because the bacteria cannot survive at a pH below 4.5, very acidic foods such as tomatoes, pears, and peaches are safe for home canning. 

FCC third ed. sequesterant in food, cross-linker, firmina aoent in canning multipurpose food additive solution unspecified concentrations dry dihydrate 99—107% of formula weights anhydrous 93.0% CaCl minimum 17... 

The poisonous botulinus organism does not grow in canned vegetables if the pH is less than 4.5. Some investigators (Journal of Chemical Education, 22, 409, [1945]) have recommended that in home canning of non-acid foods, such as beans, without a pressure canner a quantity of hydrochloric acid be added. The amount of hydrochloric acid recommended is 25 ml of 0.5 N hydrochloric acid per pint jar. 

Appert, Nicolas. (1752-1841). A French pioneer in the science of food preservation. Though not a chemist, his work on application of heat to food products led to a form of home preserving that eventually developed into the canning industry. The idea of destroying bacteria by heat treatment was later applied more exhaustively by Pasteur. 

Food literature concerning vegetables, mushrooms, fruits, nuts, and their products has already been evaluated in connection with the discussion concerning the composition of such foods. Books in which other phases of this field, such as the manufacture of juices, jams, jellies, and preserves, are described are Fruit and Vegetable Juices by Tressler, Joslyn, and Marsh the text by Cruess Apples and Apple Products by Smock and Neubert Fruit Juices and Related Products by Charley and Harrison Bananas by Von Loesecke and Citrus Products by Braverman. A number of texts dealing with canning and food preservation also discuss the manufacture of jams and jellies. 

As soon as one can of food has been packed, a statistic has been created. At least one third of the questions received at one library associated with the canning industry deal with statistics in one form or another The quantity of No. 2 cans of cream style corn packed in 1951, the size of the cherry crop in Michigan, the per capita consumption of frozen broccoli are typical queries. The variations of these questions can be endless, bringing in factors of price or numbers of employees, etc. The most comprehensive sources of statistical information are the statistical review and yearbook number of the Western Canner and Packer Canned Food Pack Statistics, published by the National Canner s Association the convention number of Quick Frozen Foods the yearbook number of Pacific Fisherman and Canning Trade Almanac, published by Canning Trade. 

In limiting this paper to the discussion of the literature of canning and preserving, the most obvious sources, the commonly used handbooks, encyclopedias, etc., which are found in most technical libraries have been omitted. It has been necessary to limit even those references which, while not strictly a part of canning, are indispensable to the literature of the field. There are many references on foods, composition of foods, agricultural chemistry, and analytical methods which are used constantly A list of some of the more commonly used tools is presented in the bibliography of this paper. 

F ew developments during the past century have added more to the increase in the standard of living than the contribution of the art and science of canning. Canning may be defined as the method of food preserving in a permanently sealed container. 

The invention of the canning process by Nicholas Appert and the extraction of sugar from the beet by Delessert, both in France during the Napoleonic Wars, were the results of food shortages caused by blockade. 

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