Sample Preparation Methods for the Determination of the Antioxidative Capacity of Apple Juices

The elevated ecological awareness nowadays led to a higher consumption of apples juices. Apples juices are rich in dietary fiber, pectin, potassium, and vitamins A and C as well as in different classes of phenolic compounds, which can protect the human body against oxidative stress by scavenging oxygen free radicals. During production and storage some bioactive compounds might decompose resulting in a reduced antioxidative capacity. Common methods for the determination of the antioxidative capacity of other food stuff are based on the extraction of the compounds under study using acetone, which is senseless in aqueous juices. But acetone might have an influence on the compounds responsible for the antioxidative capacity. Thus, self made apple juice samples were analyzed without organic solvent as well as mixed with acetone to see differences caused by the solvent. The results obtained with both procedures were compared using a paired t-test in order to see statistically significant differences in the results. No statistically significant differences were found between the testing with and without acetone. Thus the time of analysis, the amount of solvents needed, and the required labor force can be reduced without loosing analytical quality. Total content of phenolic compounds ranged from 400 to 650 mg gallic acid equivalent /L (Folin-Ciocalteu method) and antioxidative capacity from 1.0 to 1.6 mmol Trolox®/L (ABTS assay). (doi: 10.5562/cca1756

Availability of Selected (Pollutant) Elements and their Influence on Soil Composition in Urban Area

Interest in growing fruits and vegetables in private gardens is rising due to nowadays ecological awareness. Avoiding artificial fertilizers and plant protection products does not guarantee the absence of toxic substances, especially heavy metals in the soil and thus in the fruits harvested. Due to either geological bedrock weathering or environmental pollution, garden soils may be rich in certain potentially toxic elements. In the present study ten garden soils from central Croatia have been analysed by the BCR method for the contents and bioavailability of aluminium, cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc. The total amounts of the elements are in the concentration range as reported for agricultural soils in different geographical regions. Only two soils of the capital Zagreb have higher concentrations of pollutant metals, such as chromium, cobalt, copper, lead, manganese and zinc. Regarding nutrients, all soils have met the needs of common garden plants

Sastav hranjivih tvari i antioksidacijska aktivnost kore, plodova i sjemenki oskoruše (Sorbus domestica L.)

The aim of this work is to assess the nutritional value of service tree (Sorbus domestica L.) bark, fruit exocarp and mesocarp, and seeds by establishing the levels of macro- and microelements, total phenolics, flavonoids and tannins. Our results revealed that all of the tested service tree samples were rich in potassium. Bark was the best source of calcium and zinc, while seeds were the best source of magnesium. Compared to the bark and seeds, fruit exocarp and mesocarp contained significantly lower amounts of these three elements. Immature exocarp and bark contained the highest amounts of total phenolics and showed the highest antioxidant activity. Maturation significantly decreased the amount of total phenolics in fruits, as well as the antioxidant activity of total phenolics and total tannins from exocarp, but not from mesocarp. Exocarp was the richest in total flavonoids. Based on the obtained data, we have concluded that the under-utilised species S. domestica L. could serve as an important source of mineral elements and antioxidants in the human diet.Svrha je ovoga rada bila procijeniti prehrambenu vrijednost kore, egzokarpa, mezokarpa i sjemenki oskoruše (Sorbus domestica L.) na osnovi udjela makroelemenata i mikroelemenata, ukupnih fenolnih spojeva, flavonoida i tanina. Rezultati su pokazali da su svi ispitani uzorci oskoruše bogati kalijem. Kora je najbolji izvor kalcija i cinka, a sjemenke magnezija. U usporedbi s korom i sjemenkama, egzokarp i mezokarp sadržavaju znatno manje udjele ovih triju elemenata. Najveći udjel ukupnih fenolnih spojeva i najveća antioksidacijska aktivnost izmjereni su u ekstraktima nezrelog egzokarpa i kore. Dozrijevanje je značajno smanjilo ukupan sadržaj fenola u plodovima, kao i antioksidacijsku aktivnost fenolnih spojeva i tanina izoliranih iz egzokarpa, no ne i onih iz mezokarpa. Najveći udjel ukupnih flavonoida izmjeren je u egzokarpu. Na osnovi dobivenih podataka zaključili smo da bi oskoruša (S. domestica L.), kao dosad nedovoljno iskorištena biljna vrsta, mogla biti važan izvor mineralnih tvari i antioksidacijskih spojeva u ljudskoj prehrani

Harmful Elements (Al, Cd, Cr, Ni, and Pb) in Wild Berries and Fruits Collected in Croatia

Fruits and vegetables are considered a beneficial contribution to the human diet. Especially, berries contain a great deal of bioactive compounds, such as anthocyanins, organic acids, tannins, phenols, and antioxidants. Apart from organic substances, inorganic nutrients are also present in fruits. Some metals and metalloids are essential for humans, whilst others may exhibit harmful effects. Wild grown berries, collected in so-called unpolluted areas, are considered to be free of any potentially toxic ingredients. However, due to transmission processes pollutants can also reach remote areas and, furthermore, metal uptake from the soil via roots has to be taken into account. Thus, the presented study focused on the determination of Al, Cd, Cr, Ni, and Pb in lingonberries, blueberries, and rose hips collected in a non-polluted area in Croatia. Neither Cd nor Cr could be found in any sample. Ni levels were mainly up to 25 mg/kg, in a comparable range to the literature data. No health threat is to be expected by eating these fruits and berries regarding Cd, Cr, and Ni. Rose hips, however, contain Pb beyond the stipulated limit in fruits, and also Al is present at a high level (8 mg/g)

Geographic Differences in Element Accumulation in Needles of Aleppo Pines (<i>Pinus halepensis</i> Mill.) Grown in Mediterranean Region

Pine needles are widely used as bio-indicators due to their worldwide distribution and the ease of sample collection. In contrast to deciduous trees, conifers offer the possibility of monitoring long-term exposure through older needles. Pinus halepensis Miller is a pine species native to the Mediterranean region, which has been used for restoration activities in arid and semiarid areas leading to vast spatial expansion. Needles from pine trees collected in the southeastern to northwestern extension of Croatia&#8217;s coastal area at twelve sampling sites were analysed for twenty-one metals and metalloids. Statistical evaluation of the obtained data revealed significant differences for Al, As, B, Ba, Ca, Cr, Fe, K, Mg, Mn, Na, Se, and Sr between the different regions. Needles from trees growing on islands did not show elevated levels of Mg and/or Na as a result of the sea spray influence. The differences in metal accumulation are supposed to be linked to the environmental conditions at the respective sampling site, since the species was the same everywhere. By comparing the elemental contents of the soil those of with needles, it can be clearly seen, that the root as well as the foliar uptake contribute to the final amount

Mineral Composition of Elements in Walnuts and Walnut Oils

Walnuts (Juglans nigra) are considered to be a functional food. In the present study, twenty one macro-, micro-, and trace elements (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr, and Zn) were selected to be determined in walnuts and walnut oils. The beneficial content of essential elements could be shown by the obtained results, the macro-elements Ca, K, Mg, and Na being present in nuts with 1062 mg/kg, 2771 mg/kg, 1426 mg/kg, and 42.3 mg/kg, respectively. Regarding micro- and trace elements, the following order (decreasing content) was found: Mn &gt; Fe &gt; Zn &gt; B, Mo &gt; Cu &gt; Ni &gt; Co &gt; Al &gt; Sr &gt; Ba &gt; Li &gt; Pb &gt; Se &gt; Cr &gt; As &gt; Cd. Furthermore, the potentially toxic trace elements (As, Cd, Pb) determined were below the maximum allowed values in most of the investigated walnut samples. A comparison of oils and nuts revealed that the former contain lower concentrations of all elements analyzed except for Fe and Zn. This suggested the origin from contamination during oil processing. Fe influences the oil oxidation rate, thus its entry during production should be avoided

Study of the Accumulation of Toxic and Essential Ultra-Trace Elements in Fruits of Sorbus domestica L.

In the present work, the accumulation of selected toxic and essential ultra-trace elements in fruits of service tree (Sorbus domestica L.) were determined depending on harvest time. Samples were collected from the same sampling area in two different years and within one year in September and October (maturity state). Harvesting the fruits in the same area excludes the influence of metals taken up via roots, thus the impact of airborne contamination by heavy metal translocation can be studied. All samples were dried and digested using an acidic microwave assisted digestion system prior to quantification by inductively coupled plasma—sector field mass spectrometry (ICP–SFMS). The elements chosen were Arsenic and Cadmium as well as Lithium, Molybdenum, and Selenium. The Arsenic content rose with maturity in mesocarp. Cadmium found in the mesocarp was unaffected by ripeness. For Selenium and Molybdenum, no statistically significant effect of ripeness could be found on their content in mesocarp. Lithium could not be detected in the majority of fruit samples. Differences between the metal concentrations based on the year of harvest were found for Arsenic, Molybdenum, and Selenium, depending on precipitation. The drier the season, the more Arsenic was accumulated. For Molybdenum and Selenium, the opposite effect was observed

Inorganic Macro- and Micronutrients in “Superberries” Black Chokeberries (Aronia melanocarpa) and Related Teas

Black chokeberries (Aronia melanocarpa) are considered to be functional food containing high amounts of anthocyanins, phenols, antioxidants, vitamins and minerals. Whereas organic compounds are well studied, there is little research on the mineral composition of the chokeberries. Thus, the presented study is focused on the determination of Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr and Zn in black chokeberry fruits and infusions to study the metals’ extractability. The nutrients Ca, K and Mg are present in the fruits (dried matter) at g/kg level, whereas the other elements are present from µg/kg up to mg/kg level. The extraction yields of the metals from the infusion range from 4 (Al, Mn) up to 44% (Na). The toxic elements present do not pose any health risk when berries or infusions are consumed. Concluding, Aronia berries, as well as infusions derived from them, are a good dietary source of essential metals in addition to the organic compounds also contained

Metals in pine needles : characterisation of bio-indicators depending on species

Air pollution can be studied by appropriate bio-indicators, such as pine needles due to their waxy surface. Metal uptake and accumulation is determined by on growing area, but also on the respective species. Scope of the study was to analyse needles of Pinus densiflora Siebold et Zucc., Pinus nigra Arnold, Pinus sylvestris L., and Pinus thunbergiana Franco for metals and metalloids, namely Aluminum, Arsenic, Boron, Barium, Calcium, Cadmium, Cobalt, Copper, Chromium, Iron, Potassium, Lithium, Magnesium, Manganese, Molybdenum, Sodium, Nickel, Lead, Selenium, Strontium, and Zinc. Quantitation of the analytes was performed using inductively coupled plasma atomic emission spectrometry and inductively coupled plasma sector field mass spectrometry after acidic microwave-assisted digestion. The obtained data were checked for statistically significant differences. The metal levels differ between the various species, but no general tendency was found for all metals. Since the environmental conditions were the same for all sampled trees, the differences in metal accumulation are supposed to be linked to species of pine tree. The diverse accumulation behaviour can be used for treating polluted soil

Chemometric evaluation of inorganic and organic parameters found in Rosaceae plants proposed as food supplements

This study discusses the organic and inorganic composition of young inflorescence tissues of seven medical plants from the Prunus, Malus, and Chaenomeles families. These plants contain bioactive compounds with antioxidant and cytotoxic properties, and the study determined 29 elements, including essential and potentially harmful ones, established correlations with inorganic and organic compounds, as well as antioxidative and cytotoxic effects. The elemental patterns show that the plants contribute beneficial essential elements to the human diet. The levels of toxic elements in the plants are within safe limits set by the World Health Organization for medicinal herbs. The results confirmed genus- and species-specific uptake and accumulation. Positive correlations between d-block metals and alkaline earth metals in the inflorescences were found alongside statistically significant differences between analyte categories regarding macro-, micro- and trace elements and bioactive compounds. These correlations need to be considered when giving dietary recommendations or advice for uses as home-remedies