What is ethylene and why is it important to absorb it?
Ethylene (simple hydrocarbon, C2H4) is a plant hormone (phytohormone) produced naturally by plant tissue. A hormone is a natural compound existing at very low concentrations that regulates a physiological process. There are 5 main phytohormones (auxins, gibberellins, cytokines, ethylene and abscisic acid). Auxins, gibberellins, and cytokines are associated with growth and development and regulate cell division, growth, and differentiation. Ethylene and abscisic acid are antagonists of the activities of the other hormones and are mainly involved in senescence processes.
Ethylene is known as a ripening hormone due to its fundamental role in regulating the ripening of fruit. The main peculiarity of ethylene with respect to the other hormones is that it is a gas and, as such, it can leave the producing tissue and affect other surrounding fruit. Ethylene is physiologically active at very low concentrations (> 0.015 ppm). This fact is particularly important in closed areas where fresh fruits and vegetables are stored (cold stores, transport containers, packages …) since ethylene accumulates at active concentrations and accelerates the deterioration of stored products.
Fruits are divided into climacteric and non-climacteric according to their pattern of respiration and ethylene emission during ripening and according to their ability to continue to ripen or not once harvested. There is a general belief that exposure to ethylene during postharvest only affects climacteric fruits, precisely because of their ability to continue ripening once harvested. However, various studies published since the beginning of the 21st century have shown that non-climacteric fruits are even more sensitive to ethylene and at very low concentrations. Ethylene accelerates senescence and senescence is closely linked to the rotting processes typically experienced by non-climacteric fresh products.
For all the above, it is vitally important to reduce the ethylene concentration in the rooms dedicated to the conservation and transport of fresh products.