Analysis of the content of biologically active substances in the fruits of blueberries in the conditions of Polissia of Ukraine

Abstract

Goal. To determine the content of ascorbic acid, anthocyanins, flavonoids, and common polyphenolic compounds in fresh fruits of blueberry (Vaccinium corymbosum L.) varieties of different ripening periods in the conditions of Polissia of Ukraine. Methods. Seven varieties of blueberry were studied (Fiolent, Reka, Spartan, Bluecrop, Toro, Herbert, Eliot). The content of ascorbic acid and total polyphenols was determined using a spectrophotometric method using a KFK301 spectrophotometer. The content of flavonoids in the blueberry fruits was determined by the Vronska method using the ULAB 102UV spectrophotometer. The anthocyanin content was determined by the Kryventsov method using the ULAB 102UV spectrophotometer. The obtained results were processed in the Microsoft Office Excel 2019 program and presented as averages with standard errors. Results. The study was conducted at the Institute of Horticulture of NAAS (2024–2025) on the experimental site of a private farm (Ukrainian Polissia, Bucha district of the Kyiv oblast). In 2024–2025, ascorbic acid content in the stu–died varieties (Fiolent, Reka, Spartan, Bluecrop, Toro, Herbert, Eliot) of blueberries was in the range of 15.6–21.7 mg / 100 g. In 2025, they observed a decrease in the accumulation of vitamin C in the berry of all varieties of blueberries (12.6–18.4 mg / 100 g) compared to the 2024 season (18.6–25.9 mg / 100 g). In the 2024 season, the total content of polyphenolic compounds in the studied varieties of blueberries was higher (563.0–747.4 mg/100 g) compared to the 2025 season (490.1–652.1 mg / 100 g). For the period 2024–2025, the content of total polyphenols was in the range of 570.7–699.8 mg / 100 g. The content of anthocyanins in 2025 significantly increased (104.4–134.4 mg / 100 g) compared to the 2024 season (83.9–111.9 mg / 100 g), which was typical for all varieties, except for the Toro variety. For the period 2024–2025, the average content of anthocyanins in the berries of the studied varieties was in the range of 100.7–122.1 mg/100 g. During 2024–2025, the average content of flavonoids in blueberry fruits ranged from 104.0 to 125.8 mg/100 g. Conclusions. The highest content of vitamin C was fixed for the grade of early ripening Fiolent (21.7 mg / 100 g), and the lowest for the grade of average ripening Bluecrop (15.6 mg / 100 g). The highest content of polyphenols had a grade of late ripening Eliot (699.8 mg / 100 g). Among the varieties with the highest content of anthocyanins was the early grade of Fiolent (122.1 mg / 100 g). The varieties Fiolent, Spartan, Herbert, and Eliot were noted for their high content of flavonoids.