Nutritional study of copper and zinc in grapes and commercial grape juices from Spain

Determination of Concentration of Metals in Grapes Grown in Gonabad Vineyards and Assessment of Associated Health Risks

Metals are considered major public health hazards, and they are known to accumulate in fruits, which are consumed by humans because of their unique sweet taste and potential health benefits. Therefore, the aims of this study were to determine the concentration of ten metals, namely arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in red grape samples grown in Gonabad vineyards and to estimate the associated health risks of metals in terms of chronic daily intake (CDI), carcinogenic and non-carcinogenic risks by hazard quotient (HQ), hazard index (HI), and cancer risk (CR) for children, teenagers, and adults. The overall concentrations of the metals in red grapes were in the range 0.07-0.5 (mean 0.14), 0.08-0.13 (mean 0.10), 0.07-0.13 (mean 0.09), 0.06-1.49 (mean 0.29), 0.52-4.12 (mean 1.65), 6.43-42.17 (mean 19.01), 0.89-4.04 (mean 1.89), 0.07-9.23 (mean 0.71), 0.07-0.37 (mean 0.18), and 0.40-4.13 (mean 1.05) mg/kg dry weight for As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn, respectively. Based on the results, As in 11.76% and Zn in 5.88% of the samples exceeded the FAO/WHO permissible limits. The estimated non-carcinogenic and carcinogenic risk indices for children, teenagers, and adults showed that the results were lower than the critical value (1) and were in acceptable range. Therefore, red grape is safe for consumption with no impact on the human health. However, red grape consumption was just one part of fruit consumption, and the potential health hazards for inhabitants might actually be higher than in this research when other routes of heavy metal intake and also other fruits are considered.

Analysis of Selected Minerals in Homemade Grape Vinegars Obtained by Spontaneous Fermentation

Fruit vinegars are widely used as a spice and food preservative. They are considered as functional food, containing many bioactive compounds with pro-health benefits. Grape vinegars can be also a source of mineral compounds. Their quantity and diversity can be determined by environmental factors and growing conditions, such as temperature, mineral composition of the soil, heavy metal contamination, sunlight availability as well as grape variety and fruit ripeness stage. The aim of the study was to determine the content of minerals in homemade grape vinegars, obtained by spontaneous fermentation. Five different grape (Vitis vinifera L.) varieties were used in the study (Cabernet Cortis, Johanniter, Solaris, Souvignier gris and Prior). Moreover, the effect of sugar addition in the fermentation process on the mineral content was examined. The mineral content was determined using the ICP-OES method. Among the analysed samples, potassium was the most abundant element (936.07-1472.3 mg/L of vinegar). Comparative analysis showed that the content of Ca, Fe and Cr was significantly higher in vinegars prepared from red varieties than in white-coloured ones. In turn, vinegars prepared from white grape varieties contained statistically significantly higher content of potassium. Vinegar colour did not have a significant influence on the content of the remaining elements included in the analysis. Furthermore, statistical analysis did not reveal any significant differences in the content of the analysed minerals in any of the grape varieties used between the samples with and without sugar addition.

Novel approach for biosynthesizing of zinc oxide nanoparticles using Lactobacillus gasseri and their influence on microbiological, chemical, sensory properties of integrated yogurt

This research aimed to biosynthesizing zinc oxide nanoparticles (ZnO-NPs) using lactobacilli strains. All tested lactobacilli able to biosynthesis ZnO-NPs indicated by white precipitates. The characteristics of the biosynthesis ZnO-NPs from Lactobacillus gasseri were studied using UV-visible spectroscopy, TEM, SEM, DLS, FT-IR, XRD, and antimicrobial activity. The characteristic examination depicted cubic structures, pure and spherical ZnO-NPs with a diameter size of 22 nm. Antimicrobial study of ZnO-NPs displayed better higher antimicrobial activity on food pathogens in a dose-dependent manner. Moreover, integrated biosynthesis ZnO-NPs in yogurt positively affected the shelf life of yogurt during storage for four weeks without changes in the sensory evaluation. The microbiological population of fortified yogurt significantly reduced during storage than control. But chemically evaluation of fortified yogurt indicated an increase in dry matter, protein, and ash content than control. The achieved results suggested that the low amount of biosynthesized ZnO-NPs lead to the development of properties of integrated yogurt. Furthermore, the biosynthesized ZnO-NPs additive to yogurt could be a good food source for groups suffering from zinc deficiency such as the elderly groups or vegetarians who do not eat meat and at risk of zinc inadequacy.

Evaluation of Copper and Manganese Concentrations in Commercial Fruit Juices and Nectars Consumed in Brazil by GF AAS

The present work proposes a simple method for direct determination of Cu and Mn in commercial fruit juices and nectars by graphite furnace atomic absorption spectrometry (GF AAS). We analyzed samples of different flavors (orange, mango, passion fruit, peach, and grape) and brands of Brazilian commercial fruit juices and nectars. We also carried out a study to define a suitable temperature program and to optimize the calibration conditions. It was possible to determine Cu and Mn in the samples just after a simple dilution of samples with a 0.70 mol L^-1 HNO₃ solution, except in the case of grape juice. We compared the results obtained with the proposed method to those obtained after a traditional treatment based on acid digestion in a microwave oven, and no significant differences were observed (except for grape juice). The accuracy of the method was assessed through a recovery test, which provided recovery percentages in the range of 81-117%. Precision was always better than 8%, and the limits of quantification for Cu and Mn were 6 μg L^-1 and 9 μg L^-1, respectively. We analyzed twenty-two samples, and the concentrations of Cu and Mn were in the range of 24.1-321 μg L^-1 and 116-3296 μg L^-1, respectively. Statistical analysis using a two-way analysis of variance (ANOVA) at 95% confidence level showed that flavor and brand impacted on the concentration of the analytes in the samples. Among the samples analyzed, the grape juice presented the highest concentrations of both Cu and Mn.

Copper and other heavy metals in grapes: a pilot study tracing influential factors and evaluating potential risks in China

In this study, grapes (Vitis vinifera L.) were systematically sampled across the main grape-producing areas in a nationwide survey of China. Grapes from special regions, such as heavy metal polluted areas (e-waste dismantling area) and pesticide free areas (courtyard) were also collected to make a comparison. Grape skins and pulps were separated to evaluate influence of accumulation behavior, environmental transport and water cleaning efficiency to heavy metals. Levels of copper in grape skins (5.02 ± 3.18 μg/g) were higher than in pulps (3.74 ± 1.48 μg/g). Only high level of copper in two grape skins (sampled from an e-waste dismantling area) showed obvious decrease during water clean-up procedure, indicating the influence of air deposition. Statistical analysis showed no significant difference in the copper levels of grapes from markets, courtyards and e-waste dismantling areas. Concentrations and sources of chromium (Cr), manganese (Mn), nickel (Ni), cadmium (Cd), lead (Pb) and arsenic (As) were also analyzed. Higher levels of these heavy metals were observed in grape skins than pulps. Finally, we evaluated the risk of ingesting heavy metal through grapes using the estimated daily intake (EDI). No health risk was found by consuming grapes according to the data from this study.

Metabolic changes of Vitis vinifera berries and leaves exposed to Bordeaux mixture

Since the development of Bordeaux mixture in the late 1800's, copper-based fungicides have been widely used against grapevine (Vitis vinifera L.) diseases, mainly in organic but also in conventional viticulture; however their intensive use has raised phytotoxicity concerns. In this study, the composition of grape berries and leaves upon Bordeaux mixture treatment was investigated during the fructification season by a metabolomic approach. Four applications of Bordeaux mixture till 3 weeks before harvest were performed following the regular management practices of organic viticulture. Results showed that the copper-based treatment affected the content in sugars, organic acids, lipids and flavan-3-ols of grapes and leaves at specific developmental stages. Nonetheless, the levels of sucrose, glucose and fructose, and of tartaric and malic acids were not significantly affected in mature grapes. In contrast, a sharp decrease in free natural amino acids was observed, together with a reduction in protein content and in mineral nitrogen forms. The treatment with Bordeaux mixture increased by 7-fold the copper levels in tissue extracts from surface-washed mature berries.

Mineral content is related to antioxidant and antimutagenic properties of grape juice

Grape juices are an important source of food antioxidants. Unfortunately, there is little data about the mineral composition and the antioxidant, mutagenic and antimutagenic activities of grape juice in eukaryote cells. We evaluated the mineral contents (Mg, Ca, Mn, Fe, Cu, Zn, Si, S, Cl) of grape juices, the antioxidant, mutagenic and/or antimutagenic activities of the juices in the yeast Saccharomyces cerevisiae, and looked for a possible association between mineral content and antioxidant, mutagenic and/or antimutagenic activities of juice samples. Eight commercial grape juices, four purple (Bordo variety) and four white (Niagara variety), were evaluated. Most of the minerals were in similar concentrations in purple and white grape juices, except for calcium and copper; purple grapes had more calcium content and white grapes had more copper content. All grape juices had important antioxidant and antimutagenic activities in S. cerevisiae and prevented the oxidative damage provoked by hydrogen peroxide (P < 0.05). Positive correlations (P < 0.05) were observed between antioxidant and antimutagenic activities and mineral content. In this context, we concluded that the grape juices, white and purple, are an important mineral source, and these contents explain, in part, the important antioxidant and antimutagenic activities.

Trace elements in fruit juices

Fruit juices are widely consumed in tropical countries as part of habitual diet. The concentrations of several minerals in these beverages were evaluated. Four commercially available brands of juices were analyzed for cadmium, lead, copper, zinc, aluminum, iron, chromium, manganese, and molybdenum. The levels ranged from 0.02 to 0.08 mg/L for copper, from 0.05 to 0.23 mg/L for zinc, from 0.1 to 0.4 mg/L for aluminum, from 0.02 to 0.45 mg/L for iron, and from 0.01 to 0.22 mg/L for manganese. The levels of cadmium, lead, and chromium in all samples were very low or undetectable. The metal contents of fruit juices depend on a number of factors, including the soil composition, the external conditions during fruit growing and fruit harvesting, as well as on details of the fruit juice manufacturing processes employed. The concentrations of none of the metals in juice samples analyzed exceeded the limits imposed by local legislation.

Trace elements in different brands of yerba mate tea

Yerba mate (Ilex paraguariensis), a widely consumed beverage in South America, contains various biochemically active substances, among them are several minerals. This paper reports on the results of a survey of trace elements in the yerba mate infusions. Three different commercially available trademarks of I. paraguariensis were evaluated, simulating the popular mode of preparation. Atomic absorption analyses for cadmium, lead, copper, zinc, aluminum, iron, chromium, manganese, molybdenum, and silver were performed using a graphite furnace. The levels ranged from 0.03 to 0.06 mg/L for copper, from 0.41 to 1.0 mg/L for zinc, from 0.32 to 1.7 mg/L for aluminum, from 0.12 to 0.23 mg/L for iron, from 2.3 to 7.0 mg/L for manganese, and from 0.01 to 0.03 mg/L for silver. The levels of chromium did not exceed 0.005 mg/L, while molybdenum, cadmium, and lead were lower than <0.01 mg/L. Metal content in mate tea infusions depends on a number of factors, some of which are controllable and others not, but the differences among various sources are admissible. Trace elements in mate plants seem to be weakly bounded to the substrate. The concentration of biometals does not exceed the limits accepted by Brazilian and international legislation when available.

Cornelian cherry (cornus MAS L.) juices as a source of minerals in human diet

The aim of this study was to determine the mineral content of Cornelian cherry (Cornus mas L.), as this fruit and its preservatives may be considered as important nutritional supplements. Potassium (K), calcium (Ca), sodium (Na), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) were present in Cornelian cherry juice as measured by atomic absorption. Compared to other juices obtained from plum, pear, and apple, Cornelian cherry juice contained high levels of Ca, reaching 10-fold higher (323 mg/L) levels than other juices (14-77 mg/L). With respect to the remaining elements, K, Na, Fe, Zn, and Mn, the levels noted for Cornus mas juice were also higher than in other juices studied. The reverse was true for Cu, for which levels were lower. Data indicate that Cornelian cherry juices are rich in various essential elements and might be considered as an important dietary mineral supplementation for individuals deficient in nutritional elements.

Survey of lead and copper in Turkish raisins

Lead and copper levels in various types of Turkish raisins, collected from the most important production centers, were determined by electrothermal atomic absorption spectrometry. Samples were principally the products of 2005; however, two different and important raisin types produced between 2003 and 2006 were also analyzed. To investigate the source of pollution, the lead and copper content of all samples were separately determined after successive treatment with water, then with acetone and, finally, complete decomposition in a HNO(3)/H(2)SO(4)/H(2)O(2) mixture. Metal levels in raisin seeds were also determined. The results were statistically evaluated, indicating that the raisins taken from different regions and years contained a mean (range) of 0.056 (0.012-0.359) mg kg(-1) lead and 2.542 (0.770-4.706) mg kg(-1) copper. Lead concentrations in Turkish raisins were significantly lower than those found in a previous study.

Content and daily intake of copper, zinc, lead, cadmium, and mercury from dietary supplements in Mexico

This study investigates the presence of Cu, Zn, Cd, Pb, and Hg in 24 dietary supplements purchased in different health stores across the city of Hermosillo, located in the northwest of Mexico. Analysis of metals was done by microwave digestion and atomic absorption spectroscopy. The most abundant elements in dietary supplements were Cu (<0.19-137.85 microg/g) and Zn (<2.83-4785.71 microg/g), followed by Pb (<0.003-66.32 microg/g), Cd (<0.001-2.90 microg/g), and Hg (<0.24-0.85 microg/g). The estimated daily intakes of metals were below those recommended by WHO and the Institute of Medicine, showing that little risk from heavy metals is associated with the consumption of the dietary supplements analyzed. However, some products presented more than 10% of the tolerable daily intake of Pb, indicating that production processes should be improved.

Copper, zinc, calcium and magnesium content of alcoholic beverages and by-products from Spain: Nutritional supply

Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 microg Cu day(-1) and 193.3 microg Zn day(-1), 40.3 mg Ca day(-1) and 19.9 mg Mg day(-1). From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.

Validation of an electrothermal atomization atomic absorption spectrometry method for the determination of aluminum, copper, and lead in grapes

An electrothermal atomization atomic absorption spectrometry method was validated to quantify aluminum, copper, and lead in grapes. The limits of detection were 1.11, 0.19, and 0.35 micro g/L for Al, Cu, and Pb, respectively. The linearity ranges under optimized conditions were 1.11-50.0, 0.19-25, and 0.35-50.0 micro g/L for Al, Cu, and Pb, respectively. The limits of quantification were 74.0, 12.5, and 11.6 ng/g of dry weight for Al, Cu, and Pb, respectively. For all of the metals, the precision for the instrumental method was lower than 5.4% and for the analytical method, lower than 10%. The accuracy of the method was evaluated by the standard additions method, the recoveries being higher than 90% for all of the concentrations added. An interference study was also carried out in a simulated matrix, and it was verified that the deviations from the expected values were lower than 3.4% for all of the metals. The method was applied to the monitoring of the metals referred to above in 35 samples of grapes obtained in marketplaces and at farmhouses. The metals were quantified in the whole grapes, washed or not, and in the peel and pulp of unwashed grapes.