Chemical and Mechanical Properties of Japanese Quince ( <i>Chaenomeles japonica</i> (Thunb.) Lindl.) Exposed to the Ozone During Cold Storage

Abstract This study analysed the effect of applying gaseous ozone for 15 and 30 minutes on mechanical and chemical properties of six Japanese quince variety. Among the tested varieties, Gold Calif demonstrated superior mechanical durability, as it required the highest levels of force and energy to puncture and underwent the most substantial deformation. Extended storage of quince fruits for 60 days resulted in a marked decline in vitamin C levels, with an average reduction of 19.8%. Notably, the Rasa variety retained the greatest concentration of vitamin C, measuring 120.29 mg·100 g⁻¹. Exposure to gaseous ozone significantly boosted the total phenolic compound content; a 30-minute treatment led to a 6.2% increase when compared to untreated, fresh samples. After two months of storage, phenolic levels dropped by 6.5% relative to the initial fresh fruit values. Additionally, Japanese quince fruits exposed to ozone for 30 minutes exhibited enhanced antioxidant properties, reflected by a 5.8% rise in DPPH activity and a 5.5% increase in FRAP values over non-treated fruits. On the basis of the study, gaseous ozone can significantly influence chemical composition, increasing the mechanical resistance and health-promoting value of fruits.