Chiang Mai Journal of Science

Ethylene absorptive properties of zeolite A were improved by strong bases and potassium permanganate (KMnO4). The zeolite surface was activated with a solution of potassium hydroxide (KOH) and sodium hydroxide (NaOH) at concentrations of 1, 2 and 3M. Activated zeolites were soaked in a 5 w/v% solution of KMnO4 for 5 hours, with powder collected after freeze-drying. The effects of ethylene absorbers with zeolite-KMnO4 and without as control on Silk bananas during storage at room temperature were investigated. Silk bananas and zeolite-KMnO4 tablets were evaluated daily for changes in total sugar content and peel and tablet color. Silk bananas without zeolite-KMnO4 tablets were ripe after 2 days and total sugar content increased rapidly after 4 days. Contrarily, Silk bananas with zeolite-KMnO4 tablets delayed the development of the yellow color of banana peel for 5 days and total sugar content slowly increased after 5 days. On the other hand, the color of zeolite-KMnO4 tablets stored with banana changed from light violet to deep blue. °Bx of bananas without zeolite-KMnO4 tablet significantly increased after 5 days while bananas with zeolite-KMnO4 tablet remained comparatively lower for up to one week.