Efficacy of Potassium Permanganate Impregnated into Alumina Beads to Reduce Atmospheric Ethylene

Abstract

<jats:p>A systematic study was conducted on the ability of potassium permanganate absorbent to remove low levels of ethylene from the atmosphere. Absorption of potassium permanganate onto alumina beads by dipping in a saturated solution was maximal at 2 g/100 g after 2 hours at 20 °C and 4 g/100 g after 1 hour at 65 °C. Commercial alumina-based absorbents were found to contain potassium permanganate at 2.7 to 6.0 g/100 g suggesting many are prepared at elevated temperature. Trials in a closed system at 20 °C and 60% to 70% RH with alumina beads containing potassium permanganate at 4 g/100 g showed a logarithmic decrease in ethylene concentration with 90% of the ethylene removed after 2.5 to 3.0 hours. Relative humidity (RH) had a marked inverse effect on ethylene absorption with reactivity at 100% RH calculated to be 15% of that at 0% RH. Performance of potassium permanganate where ethylene was continually generated by a continuous flow of ethylene at 14 μL·h<jats:sup>-1</jats:sup> through the container showed a steady state was attained within 1 hour and maintained for 24 hours. Ethylene removal increased linearly with bead weight and ranged from 30% with 1 g to 90% with 50 g. Examination over 20 days showed a continuing decrease in rate of ethylene removal which after 14 days had declined to 10% of incoming ethylene although 44% of the original level of potassium permanganate still remained in the beads. Calculations based on known endogenous ethylene production rates suggest that at 20 °C and 90% RH, use of a potassium permanganate-alumina absorbent would be beneficial with produce having a low level of ethylene generation. Suitability for larger packages of produce generating higher ethylene levels is questionable as &gt;1 kg of absorbent may be required.</jats:p>

Preparation of a novel PdCl2–CuSO4–based ethylene scavenger supported by acidified activated carbon powder and its effects on quality and ethylene metabolism of broccoli during shelf-life

“…Agents that can remove ethylene have long been identified and some of them have been succeeded in commercial application, such as potassium permanganate (Will and Warton, 2004;Bhutia et al, 2011), activated carbon (Bailén et al, 2006) and zeolite (Aday and Caner, 2011;Esturk et al, 2014). Activated carbon and zeolite are often used as supporters for preparing ethylene absorbers, since they are relatively inexpensive, possess a complex porous structure and high surface area to support catalysts.…”

Fatty acid and sugar composition of avocado, cv. Hass, in response to treatment with an ethylene scavenger or 1-methylcyclopropene to extend storage life

“…The ethylene binding inhibitor is believed to bind irreversibly to ethylene receptors at very low concentrations (nl l À1 ), blocking or delaying the maturation processes normally induced by ethylene. When used appropriately, ethylene scavenging technologies, such as high temperature catalytic degradation (Martínez-Romero et al, 2009), activated carbon (Bailén et al, 2006) and potassium permanganate (KMnO 4 )-promoted materials (Will & Warton, 2004) can reduce ethylene levels in stored environments and therefore help maintain postharvest quality of climacteric fruits. Recently, a newly developed palladium (Pd)-promoted material (now registered as e + Ò Ethylene Remover) was shown to be effective at removing ethylene at low temperatures to sub-physiologically active levels and, accordingly, to effectively delay the climacteric-induced ripening of avocado cv.…”

Reduction of energy usage in postharvest horticulture through management of ethylene

“…Potassium permanganate is commercially available impregnated into various inert substrates from a diverse range of manufacturers in many countries, but the barrier to better commercial uptake would seem to be the lack of definitive studies determining the actual amount of potassium permanganate required to keep ethylene at a sufficiently low concentration to maintain quality in individual produce for the desired market period under specific storage conditions. Wills and Warton highlighted some of the issues when they showed that temperature, humidity and amount of absorbent all have an impact on the efficiency of ethylene removal. They also found that the efficiency of ethylene removal had declined to 10% of incoming ethylene when close to 50% of the original potassium permanganate was still present in the alumina beads.…”