What is Controlled Atmosphere, CA?

Every vegetable product undergoes metabolism. That is , every fruit is alive and breathes, consuming oxygen, not only while growing , but also after harvest . The respiration process can be described as the breakdown by oxidation of carbohydrates such as starch, sugars and acids, which are present in the vegetable tissues. The products of respiration are: heat, carbon dioxide, water vapour and some aromatic compounds. The higher the respiration rate of a fruit, the more rapid will be its senescence and deterioration and subsequent reduced storage life. For a long time, refrigeration was the only method used for the storage of fresh fruit and vegetables.It was not until 1821, biologist Berard discovered that the metabolism of fruit and vegetables was reduced when kept at low oxygen concentration. . At the beginning of the 20th century, thanks to the research of scientists KIDD and WEST, C.A. storage became a defined scientific subject. However, the real commercial boom of C.A. took place simultaneously in Europe and in the U.S.A. at the end of the '50s. The combination of a decrease in oxygen and an increase in carbon dioxide in the storage room considerably reduces respiratory activity. C.A., together with temperature reduction, has a greater effect on the vegetables' metabolism by reducing, for example, ethylene production of the fruit, by stopping the loss of chlorophyll (green colour)and by delaying pectin hydrolysis (maintaining flesh firmness), thus slowing the breakdown of vitamins and acids. From a marketing point of view, this means not only preserving the organoleptic qualities of the produce, but also reducing losses due to pathogens (fungi) and to well-known physiological disorders such as common and senescent scald and the appearance of chilling injuries. These advantages become even more evident thanks to improved techniques, first applied in Italy by Isolcell. We refer to the techniques of "Rapid C.A." and "U.L.O.".The first is a very rapid reduction of oxygen in the room (from 21 % to 5% in 36 hours). The U.L.O. atmosphere (Ultra Low Oxygen) results in produce stored in an atmosphere with an oxygen concentration of about 1 %. The choice of atmosphere depends on the type of produce (commodity and variety) and on its physiological state at the time of harvest. Compared to traditional C.A. storage, the main advantages of U.L.O. storage are a further reduction of spiration metabolism (30%) and, especially in the case of apples and pears, the control of some important physiological disorders such as scald, internal breakdown and maintenance of flesh firmness, thus leading to longer shelf-life. The ideal conditions for the medium-long term storageD.C.A. (Dynamic Controlled Atmosphere) enables you to create the ideal conditions for the medium-long term storage of any kind of fruit by allowing you to lower the oxygen levels in storage rooms to between 0.4%- 0,7% (for apples) without the risk of hypoxia and correlated physiological disorders.More than 350.000 tons of apples are stored worldwide using ISOSTORE® technology. This new technology was patented in Canada and further developed by the researcher Dr. Angelo Zanella of the Agricultural Research Institue Laimburg. It has been applied successfully for the medium-long term storage of apples and is distributed exclusively by ISOLCELL Italia S.p.A. the leading company in this sector.This technology uses fluorescence detection sensors to dynamically control the atmosphere and allows to store fruit at its lowest respiration rate.More information