Cereal crops, such as oats and barley, possess a number of valuable properties that meet the requirements for functional diet components. This review summarized the available information about bioactive compounds of oat and barley grain. The results of studying the structure and physicochemical properties of the cell wall polysaccharides of barley and oat are presented. The main components of the flavonoids formation pathway are shown and data, concerning anthocyanins biosynthesis in various barley tissues, are discussed. Moreover, we analyzed the available information about structural and regulatory genes of anthocyanin biosynthesis in Hordeum vulgare L. genome, including β-glucan biosynthesis genes in Avena sativa L species. However, there is not enough knowledge about the genes responsible for biosynthesis of β-glucans and corresponding enzymes and plant polyphenols. The review also covers contemporary studies about collections of oat and barley genetic resources held by the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). This review intended to provide information on the processes of biosynthesis of biologically active compounds in cereals that will promote further researches devoted to transcription factors controlling expression of structural genes and their role in other physiological processes in higher plants. Found achievements will allow breeders to create new highly productive varieties with the desirable properties.

Antioxidant properties, betalain profiles and biochemical composition were studied in table beets with maroon and yellow root colors. Features of dynamic changes during the growing season were described. Significant differences in antioxidant activity were found in table beet accessions with differently colored roots. Negative dynamics of antioxidant activity were observed in all accessions. Statistically significant differences were registered among the accessions in the total amounts of phenolic compounds, chlorophylls, and betalains. The group of maroon accessions demonstrated strong positive correlations between their antioxidant activity and total phenolics (r = 0.91), antioxidant activity and betacyanins (r = 0.80), and between betacyanins and phenolics (r = 0.90). The antioxidant activity in the accessions with yellow roots was associated with chlorophyll b (r = 0.85), ascorbic acid (r = 0.83), and total phenolics (r = 0.83). The data are presented on the structure of betalains in two table beet groups contrasting in their root color. The results of the study made it possible to identify key components in the biochemical profile of differently colored beetroots, associated with their high antioxidant activity. Dynamic changes were shown for the antioxidant activity and fractional composition of betalains in table beet during its growing season, and a conclusion was made concerning the higher nutritional value of maroon cultivars.

Table beet (Beta vulgaris L.) is a source of the natural red-colored food dye (E162), highly demanded for the broad spectrum of its biological activity. The relevance of this study is dictated by the lack of knowledge about the dynamics of changes in the crop’s betalain content during the growing season, which impedes identifying the optimal timing of harvesting in order to obtain the dye. This paper presents the results of research into betacyanins (BC) and betaxanthins (BX), separately in the peel and flesh of roots, in 15 differently colored table beet accessions from the collection of the N.I. Vavilov Institute (VIR). There was no statistically significant accumulation of betalains in beets during the growing season. The pigment’s significant fluctuations associated with abiotic environmental factors were shown. The ratio of BC/BX in red-colored accessions was measured: 2.65 in the peel and 2.9 in the flesh. Strong positive relationships were found between BC and BX in the peel (r = 0.97) and flesh (r = 0.79) of red-colored biotypes, which stably persisted throughout the growing season. The beetroot peel was more sensitive to temperature changes, in contrast to the flesh. The negative effect of a temperature increase on betalains in red-colored beetroots intensified on the second or third day. The pigment composition of the flesh was less susceptible to the negative impact of increased temperatures, but reacted negatively to rainfall, becoming more expressed on the second or third day. A conclusion was made about the morphotype with high betalain content. Recommended cultivars are mid-ripening, with rounded and medium-sized roots, a large number of narrow leaf blades, and short and thin petioles.

Oat is one of the most widespread and important cereal crops in the global agricultural production. Searching for new high-yielding and nutritious forms continues to be relevant, especially under the global trend of climate change, when most local oat cultivars may become economically inefficient. Spring oat accessions from VIR collection served as the material for this study; their origin is diverse, as they came from 11 countries. The basic nutritional value (the content of protein, oil, starch, and β-glucans) and characters important for breeding (plant height, panicle length, number of spikelets, number of grains per panicle, 1000 grain weight, and grain yield) were analyzed in 49 accessions of the cultivated covered oat species: Avena sativa L., A. strigosa Schreb., A. abyssinica Hochst., and A. byzantina Coch., grown under the conditions of the Russian Northwest (Leningrad Province) for two years. Variability parameters, interspecific and intervarietal differences, and the effect of weather conditions were assessed. Sources of useful agronomic traits were identified; they can be used to expand the range of the source material for the development of new high-yielding and highly nutritious oat cultivars adapted to local cultivation conditions. It is demonstrated that the VIR collection has a great potential for contemporary food and feed production and for the breeding of new oat cultivars for various purposes. Thus, the contribution of Nikolai Vavilov to the plant genetic resources investigation for the benefit of humanity is invaluable.

Background. Oat (Avena sativa L.) is one of the most important sources of protein, oil, starch and dietary fibers, in particular β-glucans. Dietary fiber serves as a source of nutrition for the intestinal microflora and significantly affects not only its composition, but also the normal functioning of the intestine as a whole. In connection with the increased interest in β-glucans as a food component and dietary supplement, there is a need in a convenient and inexpensive method for determination of β-glucans content in grain. The article provides an overview of the existing methods for the isolation and determination of soluble β-glucans in cereals: enzymatic, alkaline, alkaline-enzymatic, colorimetric; their advantages and disadvantages are noted. The main disadvantages of some methods are the complexity and duration of execution, significant cost of the required reagents, and the inability to determine the exact content of β-glucans due to their insufficient purification from various impurities.Results. This study used the example of naked and covered oat cultivars to demonstrate applicability of the gravimetric method that we developed by modifying the alkaline method. Whole grain oat flour was pretreated with a 50% ethanol solution to inactivate β-glucanase and remove free sugars, some lipids, proteins, and other substances. β-glucans were released from the aleurone layer and the endosperm with a 5% sodium hydroxide solution, and finally extracted with a 70% ethanol solution. Β-glucans floated to the surface in the form of a bunch of fibers, which was then dried at a temperature about 100-102°C to constant weight and weighed. The content of β-glucans was calculated from the dry weight (%). The isolated β-glucans were checked for the presence of accompanying substances: the content of nitrogenous substances was determined by the Kjeldahl method, and the presence of starch was determined by a qualitative reaction with Lugolʼs reagent.Conclusions. The content of β-glucans in the grain of the studied samples ranged from 3.12±0.18 up to 4.65±0.17% of the dry weight. As a result of the study, the optimal conditions of β-glucans isolation were selected: the extraction mixtures ratios, as well as the modes of centrifugation, sedimentation and drying were established. It has been shown that this method makes it possible to isolate β-glucans with a minimum impurity of nitrogenous substances (0.07-0.12%) and no traces of starch. One of the advantages of the described method is its availability for mass analysis when studying a collection of grain crops.

Cereal crops, such as oats and barley, possess a number of valuable properties that meet the requirements for functional diet components. This review summarized the available information about bioactive compounds of oat and barley grain. The results of studying the structure and physicochemical properties of the cell wall polysaccharides of barley and oat are presented. The main components of the flavonoids formation pathway are shown and data, concerning anthocyanins biosynthesis in various barley tissues, are discussed. Moreover, we analyzed the available information about structural and regulatory genes of anthocyanin biosynthesis in Hordeum vulgare L. genome, including β-glucan biosynthesis genes in Avena sativa L species. However, there is not enough knowledge about genes responsible for biosynthesis of β-glucans and corresponding enzymes and plant polyphenols. The review also covers contemporary studies about collections of oat and barley genetic resources held by VIR. This review intended to provide information on the processes of biosynthesis of biologically active compounds in cereals that will promote further researches devoted to transcription factors controlling expression of structural genes and their role in other physiological processes in higher plants. Found achievements will allow breeders to create new highly productive varieties with the desirable properties.