Improvements on the old ice box help to keep food safe
Many changes have occurred over the years in refrigeration from the old ice boxes to the modern day beautiful appliances we now take for granted.
Refrigerators are so common today that we forget that it was once little more than a box with a block of ice in it. Years ago ice was harvested from lakes and rivers in the winter to be used during the summer.
The next stage in the history of cooling foods was to add chemicals like sodium nitrate or potassium nitrate to water causing the temperature to fall. Cooling wine by this method was recorded in 1550, as were the words “to refrigerate.” The evolution to mechanical refrigeration, a compressor with refrigerant, was a long, slow process and was introduced in the last quarter of the 19th century.
In 1996, there was a change made in the type of refrigerant used to comply with the Regulatory Clean Air Act., Title 6. The old refrigerant known to most people as Freon, a trade name, was replaced with HFC 134a, a new refrigerant that does less damage to the ozone and is still just as effective in keeping food cold.
Bacteria grow most rapidly in the range of temperatures between 40 and 140 degrees Fahrenheit, some doubling in number in as little as 20 minutes. A refrigerator set at 40 degrees Fahrenheit or below will protect most foods.
There are two completely different families of bacteria – pathogen bacteria, the kind that causes foodborne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes and textures.
Pathogens, bacteria that can make you sick, can grow rapidly in the danger zone which is the temperature range between 40 and 140 degrees Fahrenheit, but they do not generally affect the taste, smell or appearance of a food. In other words, one cannot tell that a pathogen is present.
On the other hand, spoilage bacteria can grow at low temperatures, such as in the refrigerator. Eventually they cause food to develop off or bad tastes and smells.
Refrigerators should be set to maintain a temperature of 40 degrees Fahrenheit or below. Michigan State University Extension recommends having an appliance thermometer in every refrigerator and freezer that you have. An appliance thermometer allows you to know the temperature in your refrigerators and freezers. This can be critical in the event of a power outage. When the power resumes, if the refrigerator is still 40 degrees Fahrenheit, the food is safe. Foods held at temperatures above 40 degrees Fahrenheit for more than two hours should be thrown out. A full refrigerator will generally keep food cold approximately four to six hours without power, if the door is not opened more than necessary.
Appliance thermometers are inexpensive and well worth the money. They allow you to make sure your food is being kept at the correct temperature for quality and food safety reasons.