Nanoscaled Platforms Based on SiO 2 and Al 2 O 3 Impregnated with Potassium Permanganate Use Color Changes to Indicate Ethylene Removal

The development of novel tools/devices to monitor and oxidize ethylene (C2H4), a volatile compound responsible for the ripening and senescence in plants, can be a potential approach to maintain and provide information on the postharvest quality of fruits and vegetables. Here, we propose nanoscaled platforms based on silica (SiO2) and alumina (Al2O3) nanoparticles impregnated with potassium permanganate (KMnO4) that use color changes to indicate ethylene removal. SiO2 and Al2O3 in the microscale and nanoscale were impregnated with varied concentrations of KMnO4 through a simple mixture route, which systems were capable of oxidizing the ethylene in a closed atmosphere under relative humidity of 45, 60, 75, and 90%. Ethylene removal and color changes were monitored using gas chromatography and colorimetry, respectively. The nanoscaled platforms impregnated with KMnO4 were capable of scavenging ethylene more efficiently for 1-h exposure. Additionally, the color changes experienced by the nanoscaled platforms, arising from the chemical reduction of potassium permanganate, function as an indicator of ethylene removal, which is particularly suitable for postharvest application.