Influence of Temperature Conditions during Growth on Bioactive Compounds and Antioxidant Potential of Wheat and Barley Grasses

Germination under the dark as an efficient method to enrich barley hordatine aglycones and to prepare a hordatine-rich fraction

Barley (Hordeum vulgare L.; Poaceae), the second most important grain after wheat, contains phenolamides, specifically hordatines and their agmatinated precursors. Hordatines are the unique compounds found in barley, consumption of which is associated with beneficial effects for human health. This study investigated the impact of germination on the concentrations of barley phenolamides by analyzing their kinetic changes in whole barley seedlings and their distribution across shoots, seeds, and roots over a 9-day germination period under light and dark conditions. To obtain authentic standards, hordatines A and C (HA and HC) were synthesized, while hordatine B (HB) and glycosylated hordatines A and B (HAG and HBG) were isolated from a standardized hordatine-rich fraction (HRF) developed using ion exchange resins. The chemical structures were established using 1H and 13C NMR, UHPLC-HR-ESI-MS, and literature comparison, validating the presence of trans double bonds in hordatines. Germination results exhibited that darkness promotes the accumulation of barley phenolamides, with a significant increase in hordatine aglycones, particularly HA and HB. Glycosylated hordatines were abundant in early germination (Days 0 and 1; ∼7-14 mg/100 g), while hordatine aglycones became more prevalent in later stages (Days 5, 7, and 9; ∼6.5-100 mg/100 g). HA and p-coumaroyl putrescine were identified as shoot-specific and root-specific phytochemicals, respectively, with higher rates of methylation and glycosylation of hordatines observed in roots compared to shoots.

A Comprehensive Metabolomic Analysis of Volatile and Non-Volatile Compounds in Folium Artemisia argyi Tea from Different Harvest Times

To develop and utilize Folium Artemisia argyi (FAA) tea resources, UPLC-MS/MS, HS-GC-IMS, and HS-SPME/GC×GC-TOFMS were adopted to analyze its volatile and non-volatile compounds, when harvested from March to June, in combination with its antioxidant activity. Here, 1742 volatile compounds and 8726 non-volatile compounds were identified, with 75 differential volatile metabolites and 36 key flavor compounds screened. Notably, 1-octen-3-one, (E)-2-octenal, (E)-2-undecenal, and heptanal were identified as major contributors to the sweet, fruity, green, and herbal aromas, and the concentration of them was highest in June-harvest FAA tea. Furthermore, metabolomics revealed that there were 154 non-volatile differential metabolites in FAA tea at four harvest times, which were mainly related to amino acid biosynthetic pathways. Samples harvested in June also showed the strongest antioxidant capacity, which was positively correlated with D-xylitol, L-glutamic acid, honokiol, and costunolide. These findings highlight June as the optimal harvest time, providing FAA tea with superior flavor and enhanced antioxidant properties, underscoring its potential as a valuable resource for functional food development.

Intercropping of Narrow-Leafed Lupin (Lupinus angustifolius L.) and Barley (Hordeum vulgare L.) Affects the Flavonoid Composition of Both Crops

Barley (Hordeum vulgare L.) is a common cereal crop in agricultural production and is often included in legume-cereal intercropping. Flavonoids, a major class of secondary metabolites found in barley, are involved in plant defense and protection. However, the effect of intercropping on barley flavonoids remains unknown. Herein, an intercropping system involving barley and lupin (Lupinus angustifolius L.) was studied. Intercropping increased the level of luteolin in lupin roots. Lupin-barley intercropping considerably increased genistein, rutin, and apigenin in barley shoots. Genistein and apigenin were also detected in intercropped barley roots and rhizosphere soil. The three flavonoids have been reported as defense compounds, suggesting that lupin triggers a defense response in barley to strengthen its survival ability.

Evaluation of fatty acid and antioxidant variation in a complex pasture system as compared to standard cattle feed in the Great Lakes region

As the demand for grass-fed ruminant products keeps increasing, more data are needed to assess the nutritional value of feedstuffs, especially pastures. In addition, global climate change adds another challenge to the management of grasslands with projections of changing temperature and precipitation patterns. Consequently, the variations in bioactive compounds such as fatty acids and antioxidants in feeds will be harder to predict. Therefore, it is critical to report region and time-specific results of the nutritional value of feeds intended for ruminant nutrition. The objectives of this study were to compare the antioxidant and fatty acid content of commonly used feedstuffs including a complex pasture mixture from the Great Lakes Region and a traditional grain-based diet, and to assess the variations of these bioactive compounds in the pasture over the course of two grazing seasons. Weather parameters including temperature and rainfall were recorded for the length of the study. Feed samples were collected between June and September 2019 and 2020 and analyzed for nutrient composition, chlorophyll A and B, carotenoids, and total phenols. Fatty acids were analyzed by GC-MS. Correlations were reported to analyze the relationship between individual plant species, antioxidants, and fatty acids. We observed higher antioxidant parameters in the pasture compared to the grain diet. Total polyunsaturated fatty acids were higher in the pasture including α-linolenic acid while the grain diet was higher in n-6 polyunsaturated fatty acids including linoleic acid. The n-6:n-3 ratio was more beneficial in the pasture and was 50–90 times higher in the grain diet. Variations in the fatty acid profile of the pasture were observed and varied between 2019 and 2020. Plant growth cycles, climatic conditions, and grazing methods were hypothesized to cause these changes. Altogether, this study increased our knowledge about the nutritional value of feedstuffs and will help ranchers and researchers to better understand the variations of bioactive content based on region, season, and climatic conditions.