Process to retain freshness of fruits, foods, etc. with calcium peroxide.
Most fruits, vegetables and cereals produce gaseous ethylene and carbon dioxide during storage. It is said that such gaseous ethylene and carbon dioxide promote the ripening of the above foods and, thus, hasten the deterioration or perishing thereof.
Calcium peroxide performs the functions of not only retaining the freshness of the foods but also deodorizing the foods. If desired, conventional germicides and/or insecticides may be used together therewith.
It is presumed that calcium peroxide removes ethylene and carbon dioxide, which are produced from the food. That is, calcium peroxide produces oxygen and is converted into slacked line due to moisture present, and the oxygen reacts with ethylene and the calcium hydroxide catches carbon dioxide.
The convertion of calcium peroxide into calcium hydroxide and oxygen occurs by very slow degrees. The amount of oxygen is such that the amount of oxygen produced from 1g of calcium peroxide is capable of reacting with 2.5 ml of gaseous ethylene having a pressure of 0.1 atm. Further, the afore-said foods produce ethylene and carbon dioxide at very low rates, e.g. it is said that 1kg of banana produces approximately 1 mg of ethylene and approximately 1.7 mg of carbon dioxide. Therefore, the freshness of the afore-said foods can be retained for a long period of time, usually for approximately two months or more.
The amount of calcium peroxide used varies depending upon the particular food and the period for which the food is stored or transported. In general its amount may be within the range from 1 to 50 g, preferably 10 to 30 g, per Kg of the food.
The calcium peroxide powders or granules in the afore-said forms are placed in storehouses and shipholds used for storage or transportation of the foods. They also may be placed in bags and other types of containers used for storage or transportation of the food. Further, they also may be placed in a refrigerator.
It is preferable that these powders or granules are not in contact with the food, although calcium peroxide does not exert a special, undesirable influence on the food. Usually, these powders or granules are placed in a small bag or other vessel prior to use. They may also be used in the form of a thin layer, which is placed inside a small bag or which is sandwiched between two pieces of paper.