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The Content of Antioxidant Compounds and VOCs in Sorghum Grain Grown in Central and Eastern Europe
Sorghum is a plant belonging to the Poaceae family. It is drought-resistant and has low soil requirements. In the face of climate change, it is increasingly cultivated in Europe. Poland is a country with great agricultural potential; it is thus important to develop effective and economic methods of agricultural production, which is confirmed by the introduction of sorghum into cultivation. The aim of this study was to characterize the composition of bioactive compounds (i.e., phenolic acids, flavonoids, carotenoids, and phytosterols) and VOCs in sorghum grain of two varieties, i.e., white ‘Sweet Caroline’ and red ‘Sweet Susana’ grown in the temperate climate (Pętkowo, Poland (52°12′40″ N 17°15′31″ E)). The following tests were carried out: analysis of phenolic acids, flavonoids, carotenoids, phytosterols, antioxidant activity (ABTS), free phenolic acids (FPAs); elemental analysis; and water, fat and starch content analysis. Based on the conducted research, it was concluded that Poland has appropriate conditions for growing sorghum, as the content of bioactive (antioxidant) compounds was at a similar level to those grown in tropical and subtropical climates. Of the nine phenolic acids and seven flavonoids determined, the highest concentrations in both sorghum grain varieties were found for ferulic, p-coumaric and protocatechuic acids. The content of ferulic acid was three times higher in Sweet Caroline grains than in Sweet Susana grains. Differences in the content of these compounds may be the result of genetic differences between the Sweet Susana and Sweet Caroline varieties.
Relationships Between Photosynthetic Efficiency and Grain Antioxidant Content of Barley Genotypes Under Increasing Nitrogen Rates
Nitrogen fertilization may affect the functioning of photosynthesis as well as the chemical composition and antioxidant potential of cereal grains. Little is known about the relationship between the efficiency of photosynthesis and the content of phenolic compounds in barley grain, especially in conditions of varying nitrogen availability. In this regard, a field experiment was conducted to examine the responses of two primary barley genotypes with elevated phenolic compound content (TPC) in grain and an intensive modern cultivar H. v. vulgare with high protein content to increasing nitrogen fertilization (rates of 0, 30, 60 and 90 kg N ha−1) during the study years, which differed in terms of hydrothermal conditions. The leaf greenness index (SPAD) and chlorophyll fluorescence parameters were evaluated on three occasions throughout the growing season. Following the harvest, the chemical composition of the grains, including phenolic acids, flavonoids and antioxidant potential, was evaluated. The antioxidant potential and chemical composition of the grain, including TPC and protein content, depended to the greatest extent on genetic and environmental factors, and only then on nitrogen fertilization. Nitrogen increased the TPC content and antioxidant capacity ABTS+ of the grains of all studied genotypes and the protein content in H. v. vulgare grain. Rates of 60 and 90 kg N ha−1 resulted in a significant increase in the SPAD, PIabs and Fv/Fm in BBCH 34 and 57. A positive correlation was confirmed between the SPAD and PIabs and the content of TPC and ABTS+ in the grain. The dependence of qualitative characteristics on the Fv/Fm was also demonstrated. The primary genotypes are characterized by a greater genetic potential for the synthesis of phenolic compounds than the modern cultivar H. v. vulgare. The synthesis of phenolic compounds, and thus their accumulation in the grain, is clearly stimulated by unfavorable environmental factors and moderate nitrogen rates and depends on the chlorophyll content in the leaves and the efficiency of photosynthesis. N fertilization has a beneficial effect on the content of phenolic compounds in grain resulting from the improvement in the SPAD and PIabs. The chemical composition of grain and the increase in antioxidant potential are determined by the Fv/Fm, which is low under hydrothermal stress conditions.
New Insights into Bioactive Compounds of Wild-Growing Medicinal Plants
Plants contain bioactive substances and secondary metabolites that have a variety of functions, including antibacterial, antioxidant, anti-inflammatory, and anticancer activities. In this study, the content of bioactive compounds in five medicinal plants was determined, i.e., Plantago major L., Armoracia rusticana, Hypericum perforatum L., Rumex acetosa L., and Urtica dioica L., from 38 locations. Additionally, the antimicrobial effect of extracts of bioactive compounds from the above-mentioned plants was checked. The experiment used an original method of extracting bioactive compounds. Purpose of the research: the assessment of antimicrobial activity and chemical characterization of extracts obtained using our own method of isolating bioactive compounds from green parts of medical plants in Poland. Based on the research, the presence of bioactive compounds, i.e., phenolic acids and flavonoids, was found in the tested plant extracts. The results of this study suggest that the geographic parameters of the locations where these plants grow have different effects on their biochemical composition and biological activity. The results showed that all tested plants had significant antibacterial activities. Rumex acetose L. showed the highest antimicrobial activity against Escherichia coli and Salmonella enteritidis. These studies supplement the existing literature on the subject with information about the antimicrobial properties of the tested plant extracts that can be used in herbal medicine. The results have significant implications for the pharmaceutical, nutraceutical, and cosmetic sectors, establishing a foundation for future research in this area.
Determination of chemical markers affecting the occurrence of Panolis flammea Den. & Shiff.
AbstractThe research conducted so far on the chemical mechanisms of trees' defence against foliophages has not uncovered the chemical compounds biosynthesized by plants that are essential for these mechanisms. The objective of this study was to identify a chemical indicator for the presence of the pine beauty moth in Pinus sylvestris stands. Fresh needled shoots were collected from the crowns of pine trees in stands where the pine beauty moth tends to occur in large numbers, as well as from control stands. Total phenolic contents, total flavonoids contents, total chlorophyll content, terpene compounds, phenolic compound concentration, LMWOAs, sugar content, and colour analysis were conducted. Chlorophyll content, the presence of Panolis flammea in forest stands, and the colour of pine needles were discovered to be related. Variable L* correlated positively with the concentrations of chlorophyll a and b. In pine needles that were not attacked by the pine beauty moth, significantly higher concentrations of 4‐hydroxybenzoic acid, salicylic acid, chlorogenic acid, syringic acid, quercitin, and rutin were found, with the first compound having the most significant effect (4‐hydroxybenzoic acid). Based on the study results, the connected compounds in pine needles make them susceptible to insect attack. In addition, insect repellent programmes were mentioned.
The Effect of Mineral Fertilization on the Content of Bioactive Compounds in Hemp Seeds and Oil
The popularity of hemp cultivation for industrial purposes has been steadily growing for many years. With the addition of products derived from these plants to the Novel Food Catalogue, maintained by the European Commission, a significant increase in interest in hemp food is also expected. The aim of the study was to determine the characteristics of hempseed, oil, and oil cake samples produced from experimental plots grown in different conditions. The research was conducted on the Henola variety, one of the newest and most popular varieties of hemp, recently bred for grain and oil. The content of bioactive compounds in grain and oil has been subjected to detailed chemical analyses in order to determine the effect of fertilization, the method of plant cultivation, and processing conditions on their quantity. The test results and the statistical analysis carried out showed a significant impact of the tested factors on the content of some of the tested bioactive compounds. The obtained results will help in the development of an effective method of cultivation for this hemp variety in order to maximize the content of the desired bioactive compounds per unit of cultivation area.