Effect of ozone treatment on microbial and quality alteration of onions during 2 months storage.

Storing and preserving onion using pesticides is common in Brebes District. The study determined the use of ozone to reduce microorganisms and to maintain the onion quality during months of post-harvesting. There were three chambers with 2.5 m³ in size, and with a capacity of 20 kg onion used for this study. Each chamber received different treatment for 2 months; chamber I: no treatment; chamber II: pesticide; chamber III: ozone. The ozone treatment maintained better temperature and humidity for preservation. Ozone treatment was also observed to maintain low level of mass damage (1.8%) as compared to control and pesticide (6.5% and 2.4%). The protein, ash, fat and vit B1 of onions were remained high in ozone-treated chamber. Total Plate Count (CFU/mL) and the Mold Yeast Count (colonies/mL) decreased on day 30 and 60 after pesticides and ozone treatment. This study showed the importance of ozone treatment to maintain better quality of onion after months of storage as compared to pesticide treatment. Therefore, ozone can be a potential use to replace the pesticide for preservation at post-harvesting.