Effect of ultraviolet-C treatments and storage room condition on the respiration rate, weight loss, and color change of Shallots (Allium ascalonicum L.) during storage

Abstract

Shallots (Allium ascalonicum L.) is one of Indonesia’smain agricultural commodities that has many benefits and high economy value. However, this commodity is very easily damaged after being harvested, such as high weight loss, fungal attacks, sprouting, and decay. UV-C treatments is one of technologies that can be used to maintain the quality of agricultural products, safely and non-toxic. UV-C treatments, in measureable doses, capable to inhibit the growth of microbial contaminants that cause damage, so it can reduce the rate of quality deterioration. During the process, an ionization process will occur which can cause collisions of chemical bonds in DNA molecules, this reaction will inhibit microbial growth in irradiated material. When the irradiation process is stopped, there is no negative energy left, in other words, the irradiation process does not result in food being radioactive or contaminated by radiation. This study was intended to evaluate the effect of combination treatment, between the duration of ultraviolet-C irradiation and room storage temperature on the respiration rate, weight loss, and color change on shallots during storage. The material used in this study was fresh shallots which had been cleaned from roots and leaves, then treated with UV-C for 30 minutes, 60 minutes, and 90 minutes. Shallots that had been treated by UV-C were stored at various room storage condition, T 5°C-RH 93.5%, T 10°C-RH 45.5%, and T 28°C-RH 76.1% (room temperature). Quality parameters, include respiration rate, weight loss, and color change observed every 1 week for 12 weeks. The results showed that the combination of ultraviolet-C irradiation treatment and low temperature room storage was able to inhibit the respiration rate (p < 0.05), and inhibit the weight loss of shallots during storage for 12 weeks (p < 0.05). The peel color of shallots was significantly affected by room storage temperature, but wasn’t significantly affected by UV-C treatment. So that this method was considered capable of being applied to maintain the quality of the shallots during storage.