Effects of different ozone treatments on storage life and quality of orange cv. 'washington navel'

The study was carried out in the Post-harvest Physiology laboratory of Horticulture Department of Agriculture Faculty at Isparta University of Applied Sciences in 2018-2019. In the present study, the effects of different ozone applications (dissolved in water and gas form) on storage life and quality of 'Washington Navel' orange variety were investigated. For that purpose, the fruits of 9-year-old 'Washington Navel' orange variety grafted on citrus rootstock in Antalya region were used as fruit material. After different ozone treatments, the oranges were stored at 5±0.5°C and 95% relative humidity (RH) for 5 months under air conditions. Some quality analyzes (weight loss, Soluble solids content, titratable acidity, pH, respiration rate, fruit skin color and sensory evaluations) were performed on half of the oranges that were taken out of the cold storage at 30-day intervals throughout storage. Half of the other cold stored oranges were kept at 20°C and 65% RH for 5 days for shelf life evaluations, and all analyzes were repeated. According to results; it was determined that ozone treatments, in general, gave better results in terms of some quality parameters compared to control samples. Ozone treated oranges had lower respiratory rate and weight loss, and maintained fruit acidity and sensory quaity better than those of control group. Decay rate and microbiological counts were lower in ozone-treated fruit during storage. In the present thesis, it was revealed that ozone can be used as a tool for maintaining fruit quality of oranges during storage.