Elemental composition of edible nuts: fast optimization and validation procedure of an ICP-OES method.

BACKGROUND: An inductively coupled plasma-optical emission spectrometry method for the speedy simultaneous detection of 19 elements in edible nuts (walnuts: Juglans nigra; almonds: Prunus dulcis; hazelnuts: Corylus avellana; Brazil nuts: Bertholletia excelsa; cashews: Anacardium occidentalle; pistachios: Pistacia vera; and peanuts: Arachis hypogaea) available on the Serbian markets, was optimized and validated through the selection of instrumental parameters and analytical lines free from spectral interference and with the lowest matrix effects. RESULTS: The analysed macro-elements were present in the following descending order: Na > Mg > Ca > K. Of all the trace elements, the tested samples showed the highest content of Fe. The micro-element Se was detected in all the samples of nuts. The toxic elements As, Cd and Pb were either not detected or the contents were below the limit of detection. One-way analysis of variance, Student's t-test, Tukey's HSD post hoc test and hierarchical agglomerative cluster analysis were applied in the statistical analysis of the results. CONCLUSION: Based on the detected content of analysed elements it can be concluded that nuts may be a good additional source of minerals as micronutrients.

Trace element content in commercial complementary food formulated for infants and toddlers: Health risk assessment.

The study aimed to analyze trace elements content in baby purees and fruit juices and to evaluate the health risk of young children. The average daily dose, hazard quotient, hazard index and total diet hazard quotient were calculated to assess the potential health risk on per capita and consumers only groups of infants and toddlers. There was no significant health risk for studied groups regarding the intake of trace elements via purees and juices consumption. Health risk for lead was not estimated since the oral reference dose for this metal was not yet established and PTWI value was withdrawn. The average daily dose of lead for infants (0.32 - 0.46 µg/kg bw/day) and toddlers (2.01 - 2.29 µg/kg bw/day) were in accordance with the daily lead exposure intervals estimated by EFSA. Applying statistical analysis, the products were classified into three groups according to the content of trace elements.

Phenolic profiles and metal ions analyses of pulp and peel of fruits and seeds of quince (Cydonia oblonga Mill.).

Six hydroxycinnamic acids were identified and determined quantitatively in methanol and acetone extracts from quince peel and pulp, namely 3-O-caffeoylquinic acid (3-CQA), 4-p-coumaroylquinic acid (HC1), 4-O-caffeoylquinic acid (4-CQA), 5-O-caffeoylquinic acid (5-CQA), derivative of p-coumaroylquinic acid (HC2) and 3,5-dicaffeoylquinic acid (3,5-diCQA). The most abundant hydroxycinnamic acid was 5-CQA (neochlorogenic acid) with 259.12-481.4mg/kgf.w. in peel and 97.33-217.36mg/kg in quince pulp. Six flavonols were determined in the extracts from quince, quercetin-3-galactoside (Q-Ga), quercetin-3-rutinoside (Q-Ru), quercetin-3-glucoside (Q-Glu), kaempferol-3-rutinoside (K-Ru), kaempferol-3-glucoside (K-Glu) and derivative of quercetin produced in the reaction between quercetin-glucoside and p-coumaric acid (Q-Glu-p-CouA). Elemental analysis of quince seeds has not been performed previously. Also, using principal component and cluster analyses, we determined a strong negative relationship between total phenols and flavonoids, and Ni and Pb, specifically higher concentrations of these compounds were associated with lower concentrations of these metals.

Determination of streptomycin in a pharmaceutical sample based on its degradation by hydrogen peroxide in the presence of copper(II).

The kinetics of streptomycin degradation by hydrogen peroxide at pH 7.4 was investigated. The reaction was catalyzed by traces of Cu(II) ions, and it was followed spectrophotometrically at 322 nm by applying the initial-rate method. The kinetic parameters of the reaction are reported, and a rate equation is suggested. From the dependence of the relative rate constants on the temperature, the activation energy was calculated to be 57.5 kJ/mol. Based on this reaction, a kinetic method for streptomycin determination is proposed. The calibration graph is linear in the ranges 1.94 - 15.48 microg/cm(3) and 0.15 - 1.94 microg/cm(3). The influence of foreign ions and molecules on the accuracy of the determinations was investigated. The proposed kinetic method has high selectivity and good sensitivity, and enabled to determine streptomycin in pharmaceutical samples.

Exploitation of the antioxidant potential of Geranium macrorrhizum (Geraniaceae): hepatoprotective and antimicrobial activities.

In this study we evaluated in vitro (radical scavenging) and in vivo (hepatoprotective effect) antioxidant activities and antimicrobial properties of the extracts of the above- and underground parts of Geranium macrorrhizum L. (Geraniaceae), an ethnopharmacologically renowned plant species. The antioxidant activity and total phenol and flavonoid contents of four different solvent extracts were evaluated by seven different methods. The methanol extracts, administered i.p. to rats (120-480 mg/kg), were evaluated for hepatoprotective activity in a CCl4-induced hepatotoxicity model. The same extracts were tested for antimicrobial activity against seven bacterial and two fungal species. The administered methanol extracts with the highest antioxidant potential showed a significant dose-dependent hepatoprotective action against CCl4-induced liver damage in both decreasing the levels of liver transaminases and bilirubin and in reducing the extent of morphological malformations of the liver. The leaf methanol extract displayed a very strong antibacterial activity, especially against Staphylococcus aureus, with low minimal inhibitory and bactericidal concentrations. These results justify the frequent use of this plant species in folk medicine. Besides the known astringent effect, one can expect that the observed antimicrobial activity against several human pathogens contributes to the wound healing properties of this plant.

Heavy metal content in different types of smoked meat in Serbia.

Concentrations of Fe, Cu, Ni, Cr, Pb, Mn, Zn and Cd in pork, beef, turkey and chicken samples were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The mean concentration ranges in milligrams per 100 g of the studied metals in all samples were 0.6924-1.2154 for Fe, 0.6492-0.9831 for Cu, 0.0012-0.0027 for Pb, 0.041-0.0510 for Ni, 0.1186-0.1481 for Mn, 0.7257-5.2726 for Zn and 0.0042-0.0050 for Cd. The levels of analysed elements were in accordance with European standards for all metals except for manganese in all samples and for nickel in a certain number of samples. Zn level in beef was significantly higher compared to other samples, and Pb and Cd were found in concentrations well below the recommended daily intake.