Citrus fruit exhibit low levels of ethylene production and are classified as non-climacteric fruit. Although the citrus fruits produce only small amounts of ethylene it is well known that the fruit do respond to ethylene. Such as non-climacteric fruits, ethylene exposure does not hasten fruit ripening but accelerates fruit senescence.
Certain unwanted responses of citrus fruit to ethylene in storage are the enhancement of chilling injury symptoms, decay and stem end rots. Published studies indicate that the use of ethylene absorbents improved the fruit quality and reduced decay and the accumulation of off-flavours of Valencia oranges and lemons (Mc-Glasson & Eaks, 1972; Wild et al, 1976; Testoni et al, 1992).
A trial was conducted at the Stellenbosch University (South Africa) by Professor Dr M.C. Dood in Navel oranges. The goal was to compare the storage and shelf life of Navel oranges which were stored at 3.5˚C under normal air or in a room fitted with an ethylene absorbent (Bi-On). There was one storage period of five weeks followed by a shelf life test of one week at 20˚C.
The results show that the ethylene absorption was effective in removing ethylene from the storage atmosphere around the fruit. There was a difference in the ethylene production of the fruit stored with Bi-On, with this fruit producing lower amounts at each evaluation date compared to the fruit stored in the control room. These phenomena did translate into a difference in the quality of the fruit as there was a 38% reduction in the incidence of oleocellosis in the fruit stored under ethylene absorption.
Oleocellosis: a skin injury (yellow, green or brown stain of irregular shape) caused by rupture of the oil glands.