BIOCHEMICAL COMPOSITION OF MILLET GRAIN AND ITS CHANGES DURING STORAGE

The total fat content, the fatty acid composition of oil (11 fatty acids), and the total carotenoid content in grain of 8 millet varieties harvested in 2020–2021 have been investigated. The mean value of the total fat content in millet grain was 4.4±0.12%, and the varieties did not differ significantly in this parameter. The total carotenoid content averaged 6.7±0.94 mg/kg. The oil from modern millet varieties was notable for high contents of linoleic (62.4±1.32%) and oleic acids (25.1±1.67%), indicating their high nutritional value. The fatty acids in the millet grain were ranked in order of descending contents as follows: С18:2 > С18:1 > С16:0 > С18:0 > С18:2 > С24:0 > С20:0 > С16:1 > С22:0 > С20:1 > С14:1. A high content of linoleic acid in grain was recorded in the varieties Omriyane (63.6±0.07%), Sozh (62.7±0.34%), Yulin 1 (62.4±0.03%), Bila Altanka (62.8±0.04%), Kharkivske 57 (63.2±0.45%), and Zhodynske (63.3±0.31%). The varieties Sozh and Yulin 1 had an above-average content of oleic acid (26.1±0.19% and 26.0±0.01% respectively). The highest oleic acid content was observed in the variety Bohatyrske (28.5±0.15%). These data prove that high levels of linoleic and oleic acids can be combined in one genotype. The carotenoid content in the varieties Slobozhanske, Omriyane, Bila Altanka, and Yulin 1 was significantly higher than the mean value (by 0.6, 0.7, 1.1, and 0.5 mg/kg respectively). Correlation analysis has allowed determining genetic relationships between the total oils, carotenoids, and fatty acids of grain, and has shown weak to very weak correlations between their total contents. However, the oleic acid content was moderately and negatively correlated with the carotenoid content (r=-0.550) as well as with linoleic (r=-0.717), stearic (r=-0.574), eicosanoic (r=-0.590), and lignoceric (r=-0.533) acid contents. This means that breeding of high-quality millet cultivars is complicated. During long-term storage (5 years) of Kharkivske 57 grain, the total oil content decreased by 0.25%, but this change was not statistically significant. After the five-year storage, the carotenoid content decreased by 4.74 mg/kg. The acid value of oil in 2020 was 5.10 mg KOH/100 g of substance. After the five-year storage, it increased to 9.53 mg KOH/100 g of substance. No significant changes were observed in the quantity or quality of fatty acids in Kharkivske 57 oil. Nevertheless, the storage of millet grain was accompanied by a slight increase in palmitic, stearic, linoleic, linolenic, eicosanoic, eicosenoic, behenic, and lignoceric acids.