|
|
|
|
Microorganisms- The Spoilers
The effects of microorganisms can be serious, however the home canner should not be overly worried if you follow caning guidelines. It is however helpful is fyou understand how they affect acid and low-acid foods. MOLDS AND YEAST Molds and fungi appear as fuzz on food. Some molds can produce mycotoxins which are harmful to eat. Molds thrive on acids that are a protection against bacteria. Yeasts, which are fungi, cause food to ferment, which makes the unfit to eat. Acid in foods protect against the growth of baterria, even though molds and yeast are ever present. Molds and yeast are easily destroyed at temperatures between 140 degrees and 190 degrees F. Boing water processing heats foods to 212 degrees F, which is more than enough to destroy nolds and yeast without damaging the quality of your product. ENZYMES Enzymes are present in all things that are living. They promote the normal organic changes needed to substain a life cycle. The action of enzymes cause food to change flavor, texture and color. These changes makes food unappetizing. Enzymes can be destroyed by heat at temperature starting at 140 degrees F. Enzymes can be destroyed by the boiling water process. BACTERIA Bacteria are not as easily destoyred as mold, yeast and enzymes. Some bacteria grow at temperatures that would destory molds, yeast and enzymes. There are some bacteria that thrive on foods with low acids. Salmonella is destroyed when held at 140 Degrees F. Staphylococcus aureus or "staph" is destroyed if food is kept above 140 degrees F. Staph bacteria produces a toxin that must be destroyed by heating to 240 degrees f for the time specified by the canning recipe. Botulism is a food poisoning is caused by the bacterium Clostridium botulinum. These bacteria are also redily destroyed by boiling; however, their toxin producing spores cannot readily be destroyed at 212 degree F. Botulism causing bacteria thrive on low acids in the absence of air in moist enviroments exactly the conditions inside a jar of canned vegetables, meats and other low acid foods. Because bacterial spores and toxins they produce, low acid foods must be processed at 240 degress F, which is hotter than the boiling point of water. This can be accomplished only with a steam-pressure canner.
|
|
|
|
||
