Investigation of Polyphenolic Compounds in Different Varieties of Black Chokeberry Aronia melanocarpa.

The purpose of this work was to study the qualitative and quantitative composition of the main groups of biologically active substances in the fresh fruits of five different varieties of black chokeberry (Aronia melanocarpa (Michx.) Elliot), carried out within the framework of the search for available and cost-effective raw materials for food product fortification. Samples of aronia chokeberry were grown at the Federal Scientific Center named after I.V. Michurin in the Tambov region of Russia. Using a modern chemical-analytical methodology, the contents and profiles of anthocyanin pigments, proanthocyanidins, flavonoids, hydroxycinnamic acids, organic acids (malic, quinic, succinic, and citric), monosaccharides, disaccharides, and sorbitol were determined in detail. Based on the results of the study, the most promising varieties were determined in terms of the content of the main biologically active substances.

Physical and Chemical Characterization and Bioavailability Evaluation In Vivo of Amaranth Protein Concentrate.

Special attention is being paid to the study of amaranth proteins. They are characterized by a high biological value that significantly exceeds those of grain crops. The production of protein concentrate from amaranth flour includes preliminary enzymatic hydrolysis, extraction of the resulting mixture, protein precipitation, microfiltration, and freeze-drying. In our study, the obtained amaranth protein concentrate was limited by valine, with an amino acid score of 74%. The true digestibility of the amaranth protein concentrate determined in vivo was 97.6 ± 0.3%, which was significantly lower than that of casein (99.3 ± 0.2%). The protein digestibility-corrected amino acid score value of the concentrate was 72.2%. The obtained concentrate was a rich source of selenium, copper, magnesium, manganese, and iron. Ferulic acid was the only polyphenolic compound found in the amaranth protein concentrate, but its content was significantly greater compared to the original flour. Saponins were not removed completely during the process of obtaining the amaranth protein concentrate. We identified 15 saponins in the concentrate, mainly of the bidesmoside type, the sapogenins of which are related derivatives of oleanolic acid. Thus, the developed amaranth protein concentrate can be used as an ingredient in functional food products, with a high biological value.