Determination of mineral contents of wild-grown edible mushrooms

Factors affecting mushroom Pleurotus spp

Pleurotus genus is one of most extensively studied white-rot fungi due to its exceptional ligninolytic properties. It is an edible mushroom and it also has several biological effects, as it contains important bioactive molecules. In basidiomycete fungi, lignocellulolytic enzymes are affected by many typical fermentation factors, such as medium composition, ratio of carbon to nitrogen, pH, temperature, air composition, etc. The survival and multiplication of mushrooms is related to a number of factors, which may act separately or have interactive effects among them. Out that understanding challenges in handling Pleurotus species mushroom requires a fundamental understanding of their physical, chemical, biological and enzymatic properties. This review presents a practical checklist of available intrinsic and extrinsic factors, providing useful synthetic information that may help different users. An in-depth understanding of the technical features is needed for an appropriate and efficient production of Pleurotus spp.

Direct electrokinetic injection of inorganic cations from whole fruits and vegetables for capillary electrophoresis analysis

A novel approach for the direct injection from plant tissues without any sample pre-treatment has been developed by simply placing a small piece of the tissue into a capillary electrophoresis vial followed by application of a voltage for electrokinetic injection. Separations of sodium, potassium, calcium and magnesium were achieved using a BGE comprising 10mM imidazole and 2.5mM 18-crown-6-ether at pH 4.5. The addition of 2% (m/v) hydroxypropylmethyl cellulose to the separation buffer allowed for precise and accurate electrokinetic injection of ions from the plant material by halting the movement of tissue fluid into the capillary. This method provides both qualitative and quantitative data of inorganic cations, with quantitation in zucchini, mushroom and apple samples in agreement with Sector Field Inductively Coupled Plasma Mass Spectrometric analysis (r(2)=0.98, n=9). This method provides a new way for rapid, quantitative analysis by eliminating sample preparation procedures, and has great potential for a range of applications in plant science and food chemistry.

Content and Bioaccumulation of Nine Mineral Elements in Ten Mushroom Species of the Genus Boletus

Concentrations and bioconcentration potential of nine elements (Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn) in ten species of wild edible Boletus and the corresponding underlying soils were analyzed. The analyses were performed using inductively coupled plasma atomic emission spectrophotometer. Boletus showed relative abundant contents of P, K, Fe, Mg, Ca, and Na and less of Zn, Cu, and Mn. Caps compared to stalks were enriched in P, K, Cu, Mg, and Zn, while stalks were enriched in Mn. The elements such as P and K were accumulated (BCF > 1), while Ca, Fe, Mg, Mn, and Na were excluded (BCF < 1) in the fruiting bodies. The correlation analysis indicated high correlations between Cu, Mn, Ca, and Fe in the mushrooms as compared to the corresponding soils. Significant correlations were also obtained between Cu-P (r = 0.775), Fe-P (r = 0.728), and Zn-P (r = 0.76) for caps and Cu-Mg (r = 0.721), Fe-Mg (r = 0.719), Zn-Mg (r = 0.824), and Zn-P (r = 0.818) for stalks. The results of this study imply that ability of fungi to accumulate elements from substrate could be influenced by mushroom species and underlying soil substrates.

Effects of copper on induction of thiol-compounds and antioxidant enzymes by the fruiting body of Oudemansiella radicata

Oudemansiella radicata has been found to have ability to tolerate and accumulate heavy metals. In this study, to know about the metal tolerance and detoxification strategy of O. radicata, the tolerance responses in both cap and stipe of the fruiting body, including the copper content, the changes of thiol compounds production and antioxidant enzymes activities, caused by various copper stress (150-600 mg kg(-1)) during 2-6 days were investigated. Results showed that Cu content in the fruiting bodies increased with the increasing Cu concentrations and growing time, which was higher in cap than that in stipe. For thiols contents, the maximum level was in the sample at 300 mg kg(-1) Cu after 2 d both in cap and stipe, in accordance with superoxide dismutase (SOD) and glutathione reductase (GR) activities. Guaicol peroxidase (POD) activities reached maximum at 150 mg kg(-1) Cu after 4 d and 6 d, respectively in cap and stipe, while the maximum of catalase (CAT) activities was recorded at 300 and 600 mg kg(-1) Cu after 4 d in the cap and stipe, respectively. As a whole, low concentration of Cu stimulated the production of thiols and activated the antioxidant enzymes activities in the fruiting body of O. radicata after 2/4 d, while high-level Cu decreased the thiols production and enzymes activities after 4/6 d. Furthermore, the cap was more sensitive than the stipe to Cu exposure. Different indicators showed different responses to copper accumulation and the different fruiting part (cap and stipe) of O. radicata had ability to response the oxidative stress caused by Cu. Considering the metal accumulation and its own detoxification with short growing time, mushroom might have the potential to be used as bio-accumulator to deal with Cu exposure in the Cu-contaminated farmland soil.

Bioaccumulation of elements in three selected mushroom species from southwest Poland

The contents of 16 minerals and trace elements (Ag, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Pt, Ti and Zn) were analyzed in edible mushrooms (Leccinum scabrum, Boletus edulis and Boletus badius) collected in southwest Poland. Content of Co, Ni and Pb was similar in all tested mushroom species, while content of Ag, Ca, Cd, Hg and Ti was significantly higher in B. edulis than in L. scabrum and B. badius. The largest differences between these species were observed for Fe and Zn accumulation. The highest contents of these elements were noted in B. badius bodies (202 ± 88 and 137 ± 24 mg kg(-1) dry matter, respectively), lower in B. edulis (131 ± 99 and 89 ± 26 mg kg(-1) dry matter, respectively) and lowest in L. scabrum. Differences in As, Cu and Cr content between tested species were observed mainly between L. scabrum and B. badius fruiting bodies. Content of Pt was below 0.01 mg kg(-1) dry matter). In the case of Mg and Mn accumulation, differences between B. edulis and B. badius were not observed (478 and 440 mg kg(-1) dry matter for Mg and 23 and 19 mg kg(-1) dry matter for Mn), and the results showed significantly higher content of these elements than in L. scabrum bodies (312 and 10 mg kg(-1) dry matter, respectively). It is worth underlining that clear accumulation shown by the bioconcentration factor (BCF>1) observed for all three mushroom species was noted in the case of elements Ag, Cd, Co, Cu, Hg, Ni and Zn only.

Elemental characterization of wild edible plants from countryside and urban areas

Thirteen elements (Na, K, Ca, Mg, Fe, Mn, Cu, Zn, Cr, Co, Cd, Ni and Pb) in 11 different wild edible plants (WEP) (Amaranthus retroflexus, Foeniculum vulgare, Cichorium intybus, Glebionis coronaria, Sonchus spp., Borago officinalis, Diplotaxis tenuifolia, Sinapis arvensis, Papaver rhoeas, Plantago lagopus and Portulaca oleracea) collected from countryside and urban areas of Bari (Italy) were determined. B.officinalis and P.rhoeas could represent good nutritional sources of Mn and Fe, respectively, as well as A.retroflexus and S.arvensis for Ca. High intake of Pb and Cd could come from P.lagopus and A.retroflexus (1.40 and 0.13 mg kg(-1) FW, respectively). WEP may give a substantial contribution to the elements intake for consumers, but in some cases they may supply high level of elements potentially toxic for human health. Anyway, both ANOVA and PCA analyses have highlighted the low influence of the harvesting site on the elements content.

Accumulation of elements by edible mushroom species II. A comparison of aluminium, barium and nutritional element contents

The aim of the study was to compare accumulation efficiency of Al, Ba and nutritional elements (Ca, Fe, K, Mg, Mn, Na) exhibited by six edible mushrooms collected in particular regions of Poland during the last 20 years. The studied mushroom species were Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, Leccinum aurantiacum, Suillus luteus and Xerocomus badius. The highest and the lowest concentrations of the elements in tested mushroom species were 11 - 410, 34 - 337, 16785 - 34600, 140 - 607, 12 - 75 and 16 - 143 mg kg(-1)d.m., respectively. The highest average concentrations of Al, Mg and Mn were observed in Suillus luteus fruiting bodies, while for Ba, Ca, K and Na it was in Lactarius deliciosus. BCF >1 was found for K and Mg in all tested mushroom species and additionally for the highest Ca and Na concentrations of all tested mushroom species except for C. cibarius and S. luteus, respectively. For the other tested elements (Al, Ba, Fe and Mn) BCF values < 1 were recorded.

The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

The amount of the trace elements As, Ba, Cd, Cr, Cu, Hg, Li, Mn, Ni, Pb, Rb, Se, Sr, and Zn was measured in top soils and edible mushrooms, Boletus edulis, Macrolepiota procera, collected at five distinct green microhabitats inside the Lucca province, North-Central Italy (years 2008-2009). Results showed a top soil element content within the Italian statutory limits. Concerning the amount of mushroom elements, we observed significant species-differences obtaining higher levels of Ni, Rb, and Se in B. edulis or As, Pb, Cu in M. procera. Bioaccumulation factors (BCFs: element in mushroom/element in soil) resulted species-dependent and element-selective: in particular, B. edulis preferentially accumulated Se (BCFs varying from 14 to 153), while M. procera mainly concentrated Cu (BCFs varying from 5 to 15). As well, both species displayed between-site BCF differences. By a multivariate principal component approach, cluster analysis (CA), we could resolve two main clusters of soil element composition, corresponding to the most ecologically divergent sites. Besides, CA showed no cluster relating to element contents of B. edulis at the different collection sites, while a separation in groups was found for M. procera composition with respect to harvesting locations, suggesting uptake systems, in this saprotrophic species, sensitive to microhabitat. Regarding consumer safety, Cd, Hg, Pb levels resulted sometime relevant in present samples, never reaching values from current literature on mushrooms collected in urban-polluted areas. Our findings encourage a deeper assessment of the molecular mechanisms of metal intake by edible mushrooms, encompassing genetic biochemical and geo-ecological variables, with particular awareness to element bioavailability in soils and fungi.

Input of cadmium from soil into lentil and fababean seeds

In the plant, the polyphenols create in the defense mechanism against stress conditions, such as heavy metals. In view of the above aspects, therefore we will work focused on monitoring the influence of accumulation of cadmium on the formation of polyphenols in lentil and faba bean in a model vegetation conditions, in which have been deliberately added dose of Cd with 5,10,15 multiple as the limit value claimed by the limits of the Law no. 220/2004 Z.z. to assess the state of soil contamination. In all scenarios exceed the maximum permitted levels for Food Codex SR for cadmium in grains of both crops. Influence of soil contamination on the content of polyphenols was significantly confirmed, although the content of polyphenols in some variants show some tendency with increasing dose of heavy metal, but results both indicate that the formation of polyphenols (as response to stress) is probably genetically determined.

Mineral element levels in wild edible mushrooms from Yunnan, China

Ten species of wild edible mushrooms (Boletus griseus, Boletus speciosus, Lactarius hygrophoroides, Leucopaxillus giganteus, Macrocybe gigantea, Melanoleuca arcuata, Morchella deliciosa, Mycena haematopus, Pulveroboletus ravenelii, and Tricholoma matsutake) collected from Yunnan province of China, were analyzed for ten mineral elements (calcium, chromium, cobalt, copper, iron, magnesium, manganese, potassium, sodium, and zinc) contents using ICP-AES. The minimum and maximum element contents of mushrooms were determined as milligrams per kilograms dry weight for Ca (38-470), Cr (0.45-6.3), Co (0.29-2.3), Cu (13-58), Fe (22-510), Mg (84-550), Mn (1.4-70), K (1,300-4,600), Na (190-670), and Zn (16-160). The mushrooms species with the highest levels of mineral elements were B. griseus for K and Na, P. ravenelii for Cu, M. deliciosa for Mn, L. giganteus for Cr and Fe, M. gigantea for Ca, Mg and Zn, T. matsutake for Co. These results demonstrate that the mineral element contents in mushrooms are considerably species dependent and affected by environmental factors.

Characterization and prediction by near-infrared reflectance of mineral composition of rocket (Eruca vesicaria subsp. sativa and Eruca vesicaria subsp. vesicaria)

BACKGROUND

Minerals are essential for human nutrition and must be obtained from our diet. Crucifer vegetables are a good source of these nutrients. Our objectives were to determine the genetic variability for mineral content and to evaluate the use of near-infrared reflectance spectroscopy (NIRS) for prediction of ashes and minerals among and within the rocket species Eruca vesicaria subsp. sativa and vesicaria. The minerals studied were iron (Fe), copper (Cu), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and zinc (Zn).

RESULTS

The maximum mean values obtained for all the accessions (mean ± SE) were 235.5 ± 1.5 mg ashes kg(-1), 273.3 ± 4.2 mg Fe kg(-1), 18.1 ± 0.4 mg Cu kg(-1), 2.8 ± 0.1 g Na kg(-1), 71.6 ± 1.0 g K kg(-1), 64.6 ± 1.2 g Ca kg(-1), 6.8 ± 0.1 g mg kg(-1), 101.6 ± 1.2 mg Mn kg(-1), and 67.1 ± 0.4 mg Zn kg(-1) of dry weight.

CONCLUSION

The statistical analysis showed significant differences for all the minerals, except Ca, for each accession studied individually and for accessions grouped within countries. The results indicate that NIRS can be used as a rapid screening method for determining total mineral, Fe, Na, K, and Zn in rocket.

Antioxidant capacity and mineral contents of edible wild Australian mushrooms

Five selected edible wild Australian mushrooms, Morchella elata, Suillus luteus, Pleurotus eryngii, Cyttaria gunnii, and Flammulina velutipes, were evaluated for their antioxidant capacity and mineral contents. The antioxidant capacities of the methanolic extracts of the dried caps of the mushrooms were determined using a number of different chemical reactions in evaluating multi-mechanistic antioxidant activities. These included the Trolox equivalent antioxidant capacity, ferric ion reducing antioxidant power, and ferrous ion chelating activity. Mineral contents of the dried caps of the mushrooms were also determined by inductively coupled plasma-optical emission spectroscopy. The results indicated that these edible wild mushrooms have a high antioxidant capacity and all, except C. gunnii, have a high level of several essential micro-nutrients such as copper, magnesium, and zinc. It can be concluded that these edible wild mushrooms are good sources of nutritional antioxidants and a number of mineral elements.

Boron contents of some wild-growing mushrooms collected from the vicinity of boron mines in Balikesir, Turkey

The aim of the study was to determine the boron contents of some wild-growing mushrooms collected from the vicinity of several boron mines located in Balikesir, Turkey and compare the boron contents of some mushroom and soil samples. The locations of the mushroom samples collected were within the distance of 0-100, 100-500, and 500-1,000 m to the mines. Soil samples were taken from beneath randomly selected fungal fruit bodies. A total of 40 mushroom samples were found in the study area and 37 different species were identified. Among the 40 samples analyzed, the highest boron content was detected to be 273 mg kg(-1) in Suillus collinitus. Also, Tricholoma terreum (69.52 mg kg(-1)), Myxomphalia maura (36.52 mg kg(-1)), Otidea concinna (30.70 mg kg(-1)), Sepultaria arenosa (28.94 mg kg(-1)), Melanoleuca paedida (28.33 mg kg(-1)), and Lycoperdon lividum (28.31 mg kg(-1)) relatively have high levels of boron and these species are proposed as candidates for boron accumulation. The boron contents of the other mushrooms varied and a pattern was observed where the boron content was found to be decreased as the distance from the mines increased.

Influence of calcium and silicon supplementation into Pleurotus ostreatus substrates on quality of fresh and canned mushrooms

Supplements of gypsum (calcium source), pumice (silicon source) and pumice sulfate (silicon and calcium source) into substrates for oyster mushrooms (Pleurotus ostreatus) were searched for their effects on production as well as qualities of fresh and canned mushrooms. The addition of pumice up to 30% had no effect on total yield, size distribution and cap diameters. The supplementation of gypsum at 10% decreased the total yield; and although gypsum at 5% did not affect total yield, the treatment increased the proportion of large-sized caps. High content (>10%) of pumice sulfate resulted in the lower yield. Calcium and silicon contents in the fruit bodies were not influenced by supplementations. The centrifugal drip loss values and solid content of fresh mushrooms, and the percentage of weight gained and firmness of canned mushrooms, cultivated in substrates supplemented with gypsum, pumice and pumice sulfate were significantly (p≤0.05) higher than those of the control. Scanning electron micrographs revealed the more compacted hyphae of mushroom stalks supplemented with silicon and/or calcium after heat treatment, compared to the control. Supplementation of P. ostreatus substrates with 20% pumice was the most practical treatment because it showed no effect on yield and the most cost-effective.

Selective separation and preconcentration of copper (II) in environmental samples by the solid phase extraction on multi-walled carbon nanotubes

A solid phase extraction method for selective separation-preconcentration of copper (II) on multi-walled carbon nanotubes (MWNTs) prior to its flame atomic absorption spectrometric determinations has been investigated. The adsorption was achieved quantitatively on MWNTs column at pH 7.0, then the retained Cu(II) contents on the column were quantitatively eluted with 2M HNO(3). The effects of analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions etc. were investigated for optimization of the presented procedure. The preconcentration factor was 60. The detection limit for copper (II) was found as 1.46 microg/L. The method was applied to the determination of copper in environmental samples and reproducible results were obtained.