Nutritionally Important Pro-Health Active Ingredients and Antioxidant Properties of Fruits and Fruit Juice of Selected Biennial Fruiting Rubus idaeus L. Cultivars.

Raspberry fruits are an important source of many biologically active chemical compounds exerting nutritional and pro-health effects. The study presents a comparative analysis of nutritionally important bioactive chemical compounds-polyphenols; flavonoids, including anthocyanins; vitamin C; amino acids; fatty acids; and primary metabolites-contained in the fruits of three biennial fruiting cultivars, R. idaeus 'Glen Ample', 'Laszka', and 'Radziejowa', i.e., common cultivars in Poland and Europe. The antioxidant activity of fresh fruits and juice was determined with five methods. The analyses revealed the strong free radical scavenging potential of the fruits and juice, confirmed by the high concentration of nutrients, e.g., polyphenols, anthocyanins, vitamin C, amino acids, and fatty acids. The antioxidant activity of the juice determined with the ferric reducing antioxidant power (FRAP) and OH radical methods was from 2.5 to 4.0 times higher than that of the fruits. The following orders of total polyphenol contents were established in the analyzed cultivars: 'Glen Ample' < 'Laszka' < 'Radziejowa' in the fruits and 'Glen Ample' < 'Radziejowa' < 'Laszka' in the juice. The highest antioxidant activity was exhibited by the 'Radziejowa' fruits. Given their high content of dietary fiber, the fruits of the analyzed raspberry cultivars can be consumed by dieting subjects. The concentrations of vitamin C (28-34 mg/100 g) and anthocyanins (20-34 mg/100 g) indicate the biological and pharmacological activity of these fruits. The main unsaturated fatty acids in the fruits were gamma-linoleic acid (C18:2n6c) and alpha-linolenic acid (C18:3n3), which neutralize excess free radicals. The amino acids nutritionally essential to humans were dominated by leucine, arginine, and phenylalanine. This is the first comparative analysis of the antioxidant activity of fruits and juice and the contents of selected active compounds in the fruits of biennial fruiting cultivars of R. idaeus, i.e., a highly commercialized crop in Europe.

Rubi idaei fructus as a Source of Bioactive Chemical Compounds with an Important Role in Human Health and Comparison of the Antioxidant Potential of Fruits and Juice of Three Repeat-Fruiting Rubus idaeus L. Cultivars.

Rubi idaei fructus is a source of nutritionally important bioactive chemical compounds, mainly antioxidants, which strengthen the immune system and can be used in the prophylaxis and adjuvant therapies of many oxidative stress-induced diseases. There are no literature reports presenting a comprehensive comparative analysis of the antioxidant activity and nutritionally relevant metabolites contained in the fruits of repeat-fruiting raspberry cultivars, which are commonly grown in Europe. The aim of this study was to carry out a comparative analysis of the antioxidant potential (Folin-Ciocalteu, DPPH, FRAP), the content of selected primary and secondary metabolites, and the qualitative and quantitative composition of amino acids and fatty acids in the fruits of R. idaeus cv. 'Pokusa', 'Polana', and 'Polka'. The fruits of the analyzed cultivars have a low caloric value (171-219 kcal/100 g); low content of available carbohydrates (6-6.6%) and total carbohydrates (3.4-4.8%); and high levels of dietary fiber (4.7-5.8%), vitamin C (22.8-27 mg/100 g), anthocyanins (25.1-29.6 mg/100 g), and flavonoids (0.5-2.6 mg/100 g). The fruits were found to contain valuable unsaturated fatty acids (35-60%), especially MUFAs with dominant oleic, elaidic, palmitic, and erucic acids and PUFAs (α-linolenic, eicosapentaenoic, and linoleic acids). MUFAs from the ω-9 group accounted for 12-18%, whereas the content of PUFAs from the ω-3 and ω-6 groups was in the range of 15-23 and 6-21%, respectively. Exogenous amino acids, accounting for 56-62%, were dominated by leucine, phenylalanine, and lysine. The following order of the total polyphenolic content was established in the fresh fruit juice from the analyzed cultivars: 'Pokusa' < 'Polana' < 'Polka'. The different antioxidant capacity assays used in the study confirmed the high antioxidant potential of the fruits and fresh juice from the three R. idaeus cultivars. This indicates that raspberry fruits can serve as a source of nutrients and can be used as a valuable supplement in a healthy human diet and a raw material in the pharmaceutical and cosmetic industries.

Difference between Selenite and Selenate in the Regulation of Growth and Physiological Parameters of Nickel-Exposed Lettuce.

Nickel is an essential plant micronutrient; however, even at low concentrations, it may be phytotoxic. Selenium is a beneficial element with an alleviating effect that has been confirmed in the case of many abiotic stresses, including metal toxicity. The aim of this study is to assess the effect of two forms of Se (Se(IV) or Se(VI)) on the phytotoxicity, accumulation, and translocation of Ni in lettuce. Nickel causes a reduction in lettuce growth and vitality of roots, probably through increased lipid peroxidation. The application of Se(IV) to a Ni-contaminated medium resulted in a further reduction of growth, especially in the presence of 6 µM Se(IV). The growth-promoting effect of Se was found only in the 2 µM Se(VI)/10 µM Ni treatment. The application of 6 µM Se, regardless of the Se form, to the Ni-containing substrate caused an increase in shoot Ni concentration. In turn, a decrease in root Ni content was found for all Se treatments. The strong aggravation of Ni phytotoxicity in the presence of 6 µM Se(IV) was most likely related to the accumulation of high Se concentration in the roots, and the combination of high root Ni accumulation caused irreversible dysregulation of cell metabolism.

Micronutrient Status and Selected Physiological Parameters of Roots in Nickel-Exposed Sinapis alba L. Affected by Different Sulphur Levels.

An efficient method of improving the micronutrient status of Ni-treated white mustard (Sinapis alba L.) using intensive S-SO4 nutrition was developed. Twelve variants of Hoagland's nutrient solution differing in the concentration of S-SO4 (standard: 2 mM S, and elevated level: 6 or 9 mM S) and Ni (0, 0.0004, 0.04, or 0.08 mM Ni) were tested. The beneficial effect of intensive S nutrition on Ni-stressed plants was manifested by a significant rise in the content of Fe, Mn, and Zn, especially in the shoots. An increase was also found in the shoot B, Cu, and Mo content, whilst there were no changes in their root concentrations. Simultaneously, the shoot Cl concentrations dropped. The elevated level of S in the nutrient solution in general enhanced the translocation of Fe, Cu, Mo, and B in Ni-exposed plants. The beneficial effect of intensive S nutrition on the growth and micronutrient balance of Ni-exposed plants can be at least partially related to the positive changes in root surface properties, especially in cation exchange capacity (CEC). Meanwhile both reduced glutathione (GSH) and phytochelatins (PCs) probably do not significantly contribute to Ni resistance of white mustard under intensive S nutrition.

Sulfur nutrition level modifies the growth, micronutrient status, and cadmium distribution in cadmium-exposed spring wheat.

The effect of S nutrition level (standard-2 and intensive-6 or 9 mmol S L-1) on the growth, micronutrient status, and Cd concentration of Cd-exposed (0, 0.0002, 0.02, and 0.04 mmol Cd L-1) Triticum aestivum L. 'Zebra' was examined. The hypothesis that Cd-induced micronutrient imbalance in this species is alleviated by enhanced S-sulfate (S-SO4) nutrition was tested. The intensive S nutrition, especially the dose of 6 mmol L-1, to some extent alleviated Cd-induced stress by improving the adverse changes in micronutrient status and increase of the biomass. The root and shoot Fe, Cu, Mn, and Zn concentrations of Cd-exposed wheat rose at 6 and remained unaltered at 9 mmol S L-1. Particularly noteworthy is the substantial increase of Fe bioconcentration found in Cd-stressed plants at 6 mmol S L-1. The root Cu concentration increased at 6 and decreased at 9 mmol S L-1, but did not change in shoots. Simultaneously, both the high S levels elevated the shoot Cl concentration but had no effect on the root Cl concentration. There were no substantial changes in the Mo concentration. The intensive S nutrition of the Cd-treated wheat did not affect the translocation factor (TF) of Fe and B. In turn, root-to-shoot translocation of Mo and Zn was enhanced at 6 and remained unchanged at 9 mmol S L-1. The changes in TF of Cl, Cu, and Mn varied greatly, depending on the S and Cd concentrations. Intensive S nutrition of Cd-stressed wheat, as a rule, dropped the root and increased the shoot Cd concentration as well as reduced Cd bioconcentration/bioaccumulation factor enhancing root-to-shoot Cd translocation.