Relevance. The main source of the natural pigment betanin is table beet, known for its medicinal and antioxidant properties, earliness and long shelf life, rich in bioactive compounds, minerals and vitamins. This research was induced by the lack of information required by breeders to increase betanin content in beet. Metabolite profiling is an effective way to assess the interplay between individual metabolites and betanin content in table beet.Materials and methods. The material was selected from the the N.I. Vavilov Institute of plant industry (VIR) collection. Biochemical analysis was based on VIR’s guidelines, and metabolite profiling on gas chromatography, coupled with mass spectrometry.Results. 17 free amino acids were found in the beet root extract. The greatest number of positive correlations with other amino acids (r˃0.72) was found in tyrosine, alanine and phenylalanine. A significant (r = –0.66) negative correlation was observed between betanin and succinic acid, credibly associated with betalamic acid. Sucrose predominated among carbohydrates (95%). Sucrose and maltose showed a weak positive correlation with betanin. Unsaturated oleic and saturated palmitic acids dominated among fatty acids (52% and 20% of total fatty acids, respectively). Earlier-ripening and cold-resistant table beet accessions showed a predominance of unsaturated fatty acids and lower betanin content. The disclosed interactions are important for betanin-rich red beet breeding.

Relevance. Biofortification of agricultural crops with selenium is considered to be the most promising method for the human selenium status optimization.Methods. Effect of foliar biofortification of cauliflower, Polyarnaya Zvezda cv, with sodium selenate of different concentrations on yield, selenium content and biochemical characteristics of plants were investigated.Results. Enrichment of plants with selenium increased yield by 1.23-1.31 times, sugar content – 1.6 times, ascorbic acid concentration – 1.52-2 times. On the contrary, the treatment did not affect pholyphenol content and antioxidant activity of ethanolic extracts of plants. Selenium accumulation levels decreased according to inflorescences > leaves > roots. Sodium selenate solution at 75 mg/L concentration increased mass of cauliflower leaves 1.9 times and roots – 1.5 times. Consumption of 100 g of cauliflower fortified with 50 mg/L sodium selenate solution provided 100% of the daily adequate selenium consumption level. Utilization of higher sodium selenate concentrations ensured 127% and 418% of the daily adequate consumption level in case of 75 mg/L and 100 mg/L concentrations respectively. Taking into account insignificant differences between sugar content and antioxidants in cauliflower inflorescences fortified with different doses of selenium the most suitable concentration to be used was 50 mg/L.