Effect of the Removal of Ethylen Hormone by Potassium Permangenate Coated Zeolite Nanoparticles on the Increased Quality and Quantity of Storage of Iceberg Lettuce (Lactuca sativa L.) and Chinese Cabbage (Brassica pekinensis)

Internal and external accumulation of ethylene is considered as one of the most significant causes of post-harvest losses in cut leafy vegetables including lettuce and cabbage. Ethylene is an important factor in the ripening of fruits and is naturally produced in most plant tissues. Its production and accumulation during the storage can cause serious damage to the stored vegetables such as lettuce and cabbage. It plays a significant role in shelf life and can cause a marked increase in respiration rates and enhanced senescence. In vegetables and cut flowers, accelerated aging and the initiation of ripening can occur following exposure to ethylene at concentrations as low as 0.1ml/l. As senescence begins, spoilage due to indigenous bacteria can be augmented. In the presence of ethylene, vascular tissue browning is formed in the cut edge of lettuce and cabbage. Another symptom of the presence of ethylene is the appearance of brown dots and patches on the leaves. Removal of ethylene therefore is expected to increase the shelf life of the harvested lettuce and cabbage. This study was conducted to investigate the effect of removal of the ethylene using Potassium Permanganate coated nano zeolites from the storage. Potassium Permanganate and Zeolite based Nano-Molecular Filters were used in ETH 1500 machine (Bioconversion). One cultivar of lettuce and one cultivar of cabbage were used in this experiment: the Iceberg lettuce and Chinese cabbage. The experimental design was Factorial in Complete Block Design (CBD) with four replications. The two factors were the presence or absence of the machine and the kind of vegetable (lettuce and cabbage). Commercial traits affecting the marketing and shelf life of lettuce i.e. pH, texture (firmness), colour (Chroma, Hue angle and lightness) appearance and the reduction in fresh weight were measured at the beginning of the experiment (day 0) and every 7 days after that until 21 days of storage. Results showed a significant difference in the measured traits in lettuce and cabbage cultivar between the presence and the absence of the ethylene absorbing machine. Comparison of the means showed that in Chinese cabbage after 21 days of storage, significantly higher texture firmness (208.83N), color brightness (%63.21), and visible quality (3), and significantly lower reduction in fresh weight (%2.945), pH (6.42), and the cut edge vascular tissue browning (3.38) were observed in presence of the ethylene absorbing machine in comparison with the control treatment (no ethylene absorption). Similar results were obtained for Iceberg lettuce after 21 days of storage. These results indicate that using nano zeolite particles coated with potassium permanganate in a machine circulating the ethylene containing air, prevents weight loss, reduction in firmness, spoilage and increase shelf life and the quality of stored lettuce and cabbage variety.