Ethylene is a plant hormone produced naturally by fruit and other plant tissues. It is known as the ripening hormone because it regulates the series of processes associated with the ripening and senescence of fruit.
Eliminating ethylene from the environment, both in storage chambers and transport containers, where it is stored in the form of gas, is a widespread practice designed to provide a product that stays fresher for longer throughout the entire distribution chain and, as a consequence, considerably reduces the volume of losses and/or waste.
One of the ethylene elimination technologies most frequently used in the sector is chemisorption with granulated potassium permanganate. BIOCONSERVACION’s solution, the Bi-On® Filtration Media, is based on this technique.
Some years ago the practice of eliminating ethylene was also introduced to the domestic sphere. In this area BIOCONSERVACION is the market leader, offering BI-On® granular potassium permanganate (filtration media) in Tyvek® sachets that are suitable for contact with food and are placed directly in the fruit and vegetable drawers.
Other options are also available on the market, including the use of activated carbon.
The following is a comparison of the advantages and disadvantages of each of these technologies:
Ethylene elimination efficiency
The Bi-On® filtration media eliminate ethylene by means of an irreversible oxidation reaction
3 C2H4 + 12 KMnO4 ---------- 12 MnO2 + 12 KOH + 6 CO2
Activated carbon does not eliminate the ethylene, it only traps it through weak, reversible physical connections. As a consequence, small changes in the temperature or ventilation of the chamber or container can allow the ethylene trapped by the activated carbon to be released into the air again
Unlike the Bi-On® filtration media, activated carbon is greatly affected by relative humidity. In fact, in environments with high relative humidity, it practically only traps humidity, barely reducing the ethylene level at all.
Comparative tests have been carried out in the laboratory to ascertain the differences between Bi-On® sachets and activated carbon in removing ethylene. The graph shows the difference in their performance in eliminating ethylene:
Fig. 1: Elimination of ethylene with Bi-On® and a product based on activated carbon*
With regard to the perception that activated carbon (made from coconut) is a safer alternative to Bi-On® filtration media, we can argue the following:
Only 12% of granular Bi-On® consists of potassium permanganate (KMnO4), the rest is made up of natural clays. As the ethylene is eliminated the potassium permanganate (KMnO4) turns into manganese dioxide (MnO2), an innocuous compound.
The BI-On® filtration medium never comes into contact with the fresh product. The specific properties of the material used (Tyvek®) allow air but not moisture into the sachet, thus avoiding any risk of dripping.
Tyvek® is approved for contact with food under FDA and EU regulations.
Granular Bi-On® is an approved technology for use with organic products under European Council Regulation 834/2007 and the American NOP.