Biochemical contents of highbush blueberry fruits grown in the Western Forest-Steppe of Ukraine
National Academy of Agrarian Sciences of Ukraine, Institute of Horticulture, Sadova Str., 23, UA03027 Novosilky, Kyiv region, Ukraine
The study of the physical and consumption qualitative indices of the highbush blueberries (the cultivars ‘Reca’, ‘Elizabeth’ and ‘Bluegold’) in the Western Lisosteppe of Ukraine has shown that the biggest fruit mass was accumulated by the berries of two last mentioned vs (1.54–1.50 g respectively). ‘Bluegold’ has this indicator as the least variable (V = 10.6%). The accumulation of fruit mass of all studied cultivars was facilitated by a moderately humid period of their development in 2018 with a hydrothermal coefficient of 1.1–1.2. The favorable year for the intensive synthesis of the dry matter and soluble solids was 2017 when the precipitation amount did not exceed 44 mm. The biggest number of the mentioned substances during the research period was accumulated by fruits of ‘Reca’ – 17.48 and 13.24%, respectively. It was established that the dry matter content had high level of stability (V = 8.2%), and middle was for soluble solids (V = 19.5%). The amount of monosaccharides from which glucose and fructose were investigated in fruits varied from 6.11 (‘Bluegold’) to 7.85 (‘Reca’), it was slightly lower in ‘Elizabeth’ berries – 7.78%. ‘Bluegold’ fruits were characterized by high stability (B = 9.6%) of the biggest content of titrated acids among the studied cultivars (2.42%). The dry weather with low number of precipitation in 2017 (hydrothermal coefficient 0.3–0.4) was favourable for the accumulation of both the mentioned acids and vitamin C in fruits of highbush blueberries in the period of their formation and growth. The amount of ascorbic acid in fruits in the specified year varied from 20.00 mg 100 g-1 WM (‘Reca’) to 27.00 mg 100 g-1 WM (‘Elizabeth’) with an intermediate value of 22.50 mg 100 g-1 WM (‘Bluegold’). The latest of the mentioned varieties had the most constant index (V = 7.0%). The content of polyphenolic substances was slightly dependent on weather conditions during the period of fruit growth, the coefficients of variation were 6.2% (‘Reca’), 7.0% (‘Elizabeth’) and 5.8% (‘Bluegold’). The fruits of the last mentioned cultivars were characterized with the biggest anthocyanins and chalcones content (68 and 13 mg 100 g-1 WM, respectively). The substantial indirect dependence of the content of the nutritive substances and anthocyanins on the berry mass was revealed in the ‘Reca’ fruits.