THE APPLICATION OF MANGANESE DECORATED TIO2 AS AN ETHYLENE SCAVENGER TO EXTEND THE SHELF LIFE OF BANANA FRUIT

• Main Author: Gianirfan Nugroho, Fairuz
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/75086
• Institution: Institut Teknologi Bandung

Apart from being a good source of nutrition, bananas are also an essential commodity in Indonesia and are currently the most widely produced fruit. However, bananas exhibit fast ripening and low shelf life because they are considered a climacteric fruit. One technology capable of extending the shelf life of bananas is using modified atmosphere storage coupled with an ethylene scavenging system. Ethylene scavenging materials serve to reduce ethylene levels and slow down the ripening process. TiO2, with its non-toxic nature, can act as an ethylene scavenger through photocatalytic degradation. In this study, Mn-decorated TiO2 (TiO2/Mn) was synthesized, and its effects on TiO2 activity in the visible light region and its performance as an ethylene scavenger are investigated. The characterization methods used are UV-vis spectroscopy, Raman spectroscopy, and scanning electron microscopy equipped with energy-dispersive X-Ray spectroscopy (EDX). The photocatalytic activity was tested using two approaches, namely towards rhodamine B dye and directly to pure ethylene gas. Then TiO2/Mn was added to the banana storage system as an application test for ripening. Factors observed from bananas were changes in terms of colour, fruit hardness (testing using a penetrometer), ethylene formation rate, respiration rate (using CO2 and ethylene sensors), and starch hydrolysis level (measuring the value of total dissolved solids). The results of the EDX characterization confirmed the presence of an Mn species evenly distributed on the TiO2 surface. Then UV-visible spectroscopy showed that Mn decoration increased the uptake of TiO2 in the visible light range. On the other hand, the structure and size of the particles did not change significantly. In the photodegradation test of rhodamine B and ethylene, it was found that the activity of TiO2 decreased when exposed to UV light but increased when exposed to visible light. In the visible light range, TiO2/Mn was more active by irradiating blue and red lights, whereas no activity was observed under green light. Based on the infrared absorption from the ethylene reactor during the reaction with visible light irradiation, it was found that ethylene undergoes partial oxidation to form formic acid. This is caused by reduced oxidative species on the catalyst’s surface, so ethylene is released from the surface before being oxidized to carbon dioxide. Based on the colour of TiO2/Mn, it is assumed that the Mn species is MnO2, where the interaction between TiO2 and Mn is a type I heterojunction. Furthermore, tests on bananas confirmed that TiO2/Mn can be used as an ethylene scavenger. Bananas stored in containers in the presence of TiO2/Mn showed changes in colour, ethylene production rate, respiration rate, hardness, and amount of dissolved sugar which signals delayed ripening.