Dynamics of bioactive substances in the fruits of Ziziphus jujuba Mill. during refrigerated storage in a modified gas atmosphere

Fresh fruits of jujube (Ziziphus jujube Mill.) are distinguished by a high¬ content of vitamin C, phenolic compounds, organ-ic acids, sugars and microelements. However, their shelf life is short. The effect of a modified gas atmosphere on the dy-namics of biologically active substances of jujube fruits during refrigerated storage (4 ±2)°C was studied to determine their shelf life. The objects of the study were fruits of varieties "Kitayskiy 2A" and "Ta yan tszao" harvested in 2023 and intro-duced by the Nikitsky Botanical Garden, Crimea. Refrigerated storage of packaged fruits was carried out for 6 months. Dur-ing the storage the content of dry matter (moisture), of sugars, free organic acids, vitamin C, phenolic compounds, and iodine was determined with a frequency of 1.5 months. It was found that during the first storage period the decrease in the content of the biologically active substances studied from 15% (monosaccharides) to 25% (organic acids) is observed. The dynamics of phenolic compounds during storage revealed the decrease of their content in the fruits of the jujube variety "Ta yan tszao" which is associated with oxidative degradation processes, and the increase in the content in the fruits of the jujube variety "Kitayskiy 2A" which is due to the release of aglycones during the hydrolysis of their glycoside forms. Rec-ommended shelf life for fruits Ziziphus jujube Mill. of varieties "Kitayskiy 2A" and "Ta yan tszao" in modified gas atmos-phere – nitrogen (70%) : carbon dioxide (29%) : oxygen (1%) at a temperature of (4±2)°C is about 3 months.