No abstract

This research aimed to determine the effect of different harvesting times on the chemical composition of stinging nettle (Urtica dioica L.). The leaves of nettle were harvested at the same place once a month in the period of April–September 2019. The analysis focused on the contents of dry matter, soluble solids, ascorbic acid, titratable acidity, chlorophyll a and chlorophyll b, total carotenoids, total phenolic compounds, antioxidant activity, ash content, and macro- and microelements. The nettles harvested in April were characterized by the highest levels of soluble solids and some macro-and microelements (P, K, Fe, Zn). The plants harvested in May were distinguished for titratable acidity, chlorophyll a, chlorophyll b, and carotenoid contents. In this month, the plants were determined to have the highest antioxidant activity during the entire vegetation period. The plants collected in July contained the highest amount of Mn, but the antioxidant activity of these plants was the lowest during the vegetation period. In August, the plants had the highest levels of ascorbic acid, phenolic compounds, and ash, while the plants collected in September were characterized by having the highest amounts of Ca, Mg, and B as compared to those established in other months of vegetation.

The aim of this study was to determine the level of antioxidants in the seeds of wheat, lentil, pea, radish, broccoli, alfalfa, sunflower and amaranth germinated for 24, 72 and 120 hours. Following germination, the highest increases in the total phenols corresponded to 5.39, 4.62 and 2.20 times in broccoli, radish and alfalfa seeds respectively. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was higher after germination for 120 hours in all the seed types as compared with the non-germinated seeds. In radish, sunflower and alfalfa seeds, the ability to scavenge ABTS increased by 5.19, 1.34 and 2.90 times respectively, after germination. According to the different changes in the amounts of tocopherol isomers in germinating seeds can be summarized, that the α-tocopherol content increased and that of β-, γ-, δ-tocopherol decreased irrespective of the species, therefore suitable for germination time and seeds variety allows having products with a high nutritional and antioxidant properties. Efectos del tiempo de germinación en las propiedades antioxidantes de semillas comestibles RESUMEN El presente estudio se propuso determinar el nivel de antioxidantes existente en semillas de trigo, lenteja, guisante [arveja], rábano, brócoli, alfalfa, girasol y amaranto que germinaron durante 24, 72 y 120 horas. Después de su germinación, se comprobó que los mayores aumentos en fenoles totales se registraron en semillas de brócoli, rábano y alfalfa, siendo de 5.39, 4.62 y 2.20 veces más, respectivamente. En comparación con las semillas no germinadas, la eliminación del radical 1,1-difenilpicrilhidrazil (DPPH) fue más activa en todos los tipos de semillas tras su germinación durante 120 horas. Una vez germinadas, las semillas de rábano, girasol y alfalfa incrementaron su capacidad de eliminar el compuesto ABTS en 5.19, 1.34 y 2.90 veces, respectivamente. En términos de los distintos cambios en las cantidades de isómeros de tocoferol en las semillas germinadas, puede resumirse que el contenido de α-tocoferol aumentó, mientras que los de β-, γy δ-tocoferol disminuyeron sin importar la especie. Por lo tanto, si se toma en cuenta el tiempo de germinación y la variedad de semillas es posible elaborar productos con abundantes propiedades nutricionales y antioxidantes.

The aim of this study was to evaluate the impact of abiotic stress conditions on the synthesis of compounds with antioxidant properties in germinating seeds. The seeds of edible lentils (Lens culinaris L.), alfalfa (Medicago sativa L.), and mung beans (Vigna radiata L.) were germinated for 120 hours. We studied the influence of abiotic stress on the amount of dry matter, vitamin C and phenolic compounds, as well as flavonoids, in germinated seeds. The use of higher than optimal germination temperatures led to a higher accumulation of dry matter in the mung bean, while the accumulation of phenolic compounds and flavonoids was higher in the alfalfa sprouted seeds. Oxidative stress substantially increased the content of dry matter in the seeds of mung bean, and more vitamin C was found in the lentils. The conditions of abiotic stress in lentil seeds during their sprouting reduced the amount of phenolic compounds in comparison to that in the control variant of the seeds. However, these same conditions (with the exception of oxidative stress) benefitted the accumulation of phenolic compounds in alfalfa seeds.

The purpose of this study was to investigate the qualitative properties of cookies with the addition of raspberry, red currants and strawberry pomace flour. Cookies were prepared by substitution of wheat flour with berry pomace flour (10%, 15% and 20%) and evaluated in terms of their proximate composition, physical characteristics, and functional and sensory properties. Berry pomace-supplemented cookies had significantly higher dietary fibre content and different fibre fractions NDF (neutral detergent fibre), ADF (acid detergent fibre), MADF (insoluble fibre fraction of modified acid detergent solution) as well as WSCs (water soluble carbohydrates) content. Correlation analysis results showed that cookie hardness was significantly correlated with dietary fibre content. The raspberry, red currant and strawberry flours contained 49.88%, 33.13% and 24.25% of dietary fibre, respectively. The colour of the cookies was measured using a Color Flex spectrophotometer. The average L*, a*, and b* values ranged from 37.35 to 68.29, from 7.08 to 13.18, and from 20.12 to 34.73, respectively.