Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 4/11 ( 124 ) 2023 20 IMPROVING THE STORAGE TECHNOLOGY OF PERSIMMON FRUIT (DIOSPYROS KAKI L.) IN THE REFRIGERATION CHAMBER Yashar Omarov Doctor of Philosophy in Biology, Assistant Professor* Sevda Gurbanova Doctor of Philosophy in Biology, Acting Assistant Professor* Ulduz Babayeva Doctor of Philosophy in Technics, Acting Assistant Professor* Afet Gasimova Corresponding author Doctor of Philosophy in Technics, Associate Professor* E-mail: afet-kasumova@rambler.ru Elnur Heydarov Doctor of Philosophy in Technics, Associate Professor* Gultakin Gasimova Doctor of Philosophy in Biology, Acting Assistant Professor Department of Ecology and Nature Conservation Ganja State University Haydar Aliyev str., 429, Ganja, Azerbaijan, AZ 2000 Ahad Nabiyev Doctor of Biological Sciences, Professor* *Department of Food Engineering and Expertise Azerbaijan Technological University Shah Ismayil Khatai ave., 103, Ganja, Azerbaijan, AZ 2011 Persimmon fruits (Diospyros kaki L.) attract the attention of researchers due to their high nutritional and medicinal value. The composition of persimmon is rich in nutrients. The object of research is the storage technology of persimmon. Fully ripe persimmon varieties Khachia and Khiakume were used as research material. If the activity of enzymes is inhibited or reduced during refrigerated storage using a controlled gas environment, then the consumption of nutrients for respiration will decrease, and the fruits will retain their original appearance. The persimmon varieties used were stored in refrigerators for 5 months in five variants. In persimmon fruits of both varieties, quantitative changes in the main indicators during refrigerated storage were studied. The regularities of changes in the activity of enzymes of the oxidoructase class depending on the composition of the controlled gas medium and the content of phenolic compounds were considered. As a result of the analyzes, a rational regime for storing persimmon varieties in a refrigerator under CGE conditions with a gas composition of 3–4 % CO 2 and 2–3 % O 2 , a temperature of ‒2...–3 °C and an air humidity of 90–95 % was determined. During the storage period, the activity of all enzymes, except for ascorbate oxidase, completely ceased (except for the catalase enzyme in the Khachia variety). During long-term storage of the Khachia variety in a refrigerator, the activity of the enzyme ascorbate oxidase decreased by 94 %, o-diphenol oxidase and peroxidase decreased by 100 %, catalase by 95.5 %. Ascorbate oxidase activity decreased by 94.5 % in persimmon fruits of the Khiakume variety, and the activity of other enzymes was completely inhibited. To achieve this result, it is important that the activity of oxidoreductases decreases or passes into an inhibitory state. The results make it possible to regulate the quality indicators of persimmon varieties depending on their storage modes and use them to provide people with fresh fruits not seasonally but for a long time Keywords: persimmon varieties – Khachia, Khiakume, oxidoreductases, total sugar, phenolic compounds UDC 66.664 DOI: 10.15587/1729-4061.2023.285444 How to Cite: Omarov, Y., Gurbanova, S., Babayeva, U., Gasimova, G., Haydarov, E., Gasimova, A., Nabiyev, A. (2023). Improving the storage technology of persimmon fruit (Diospyros kaki L.) in the refrigeration chamber. Eastern-European Journal of Enterprise Technologies, 4 (11 (124)), 20–36. doi: https://doi.org/10.15587/1729-4061.2023.285444 Received date 09.06.2023 Accepted date 17.08.2023 Published date 30.08.2023 Copyright © 2023, Authors. This is an open access article under the Creative Commons CC BY license 1. Introduction Persimmon fruits (Diospyros kaki L.), widely distributed in countries with a temperate climate, are of great impor- tance in food production and fresh consumption due to their environmental safety, high nutritional value, and therapeu- tic and prophylactic properties [1]. Their composition is rich in sugars, vitamins, phenolic compounds, mainly β-carotene, macro- and microelements, as well as iodine, which are necessary for the normal development of the human body. A distinctive feature of persimmon fruits from other fruits is that no chemicals are used during their cultivation and ripening [2]. This is due to the fact that persimmon fruits are significantly rich in phenolic compounds, mainly flavonoids, procyanidins, polyphenols, which are natural antioxidants and have antimicrobial and antiviral properties [3]. Since the composition of this fruit is rich in various representatives of phenolic compounds, it helps eliminate radiation from the human body and reduces the risk of developing malignant tumors and dangerous viruses [4]. Mineral substances of persimmon fruits are involved in the synthesis of proteins, enzymes and hormones that are im-