Fatty acid and sugar compositions,and nutritional value of five wild edible mushrooms from Northeast Portugal

The chemical composition and nutritional value of five wild edible mushroom species (Agaricus arvensis, Lactarius deliciosus, Leucopaxillus giganteus, Sarcodon imbricatus, Tricholoma portentosum) commonly consumed in the Trás-os-Montes region of Northeast Portugal was determined. Chemical composition evaluation included moisture, total oil content, crude protein, ash, carbohydrates, and nutritional value determination. The macronutrient profile in general revealed that the wild mushrooms were rich sources of protein and carbohydrates, and had low amounts of fat. On the basis of the proximate analysis, it can be calculated that an edible portion of 100 g of these mushrooms provides, on average, 28 kcal (118 kJ). The analysis of fatty acid composition, performed by gas–liquid chromatography coupled to a flame ionization detector, allowed the quantification of fifteen fatty acids. Unsaturated fatty acids and, in particular, oleic and linoleic acids, were predominant. The composition in individual sugars was also determined by high performance liquid chromatography coupled to a refraction index detector, mannitol and trehalose being the most abundant sugars.     

Mercury content of some wild edible mushrooms

 The mercury (Hg) content of 112 samples of common, wild edible mushrooms was analysed by atomic absorption spectrometry. The average Hg content of all the samples was 1.72 mg/kg dry mass (DM) but the Hg concentrations found in different taxonomic groups (genera and species varied) remarkably. Although different sampling locations obviously have an effect on the Hg concentration of sporocarps, we found evidence for a Hg-accumulating capacity of some taxonomic groups. In addition to Agaricus and Macrolepiota, where the phenomenon of mercury accumulation has already been described, our results indicate high Hg levels in samples of Lycoperdon perlatum (average 2.94 mg/kg DM) and in Lepista species (average 3.02 mg/kg DM). These data confirm the need for greater attention to be given to Hg levels in wild common mushrooms, especially to Hg-accumulating species. Received: 20 February 1997     

Mercury content of some wild edible mushrooms

 The mercury (Hg) content of 112 samples of common, wild edible mushrooms was analysed by atomic absorption spectrometry. The average Hg content of all the samples was 1.72 mg/kg dry mass (DM) but the Hg concentrations found in different taxonomic groups (genera and species varied) remarkably. Although different sampling locations obviously have an effect on the Hg concentration of sporocarps, we found evidence for a Hg-accumulating capacity of some taxonomic groups. In addition to Agaricus and Macrolepiota, where the phenomenon of mercury accumulation has already been described, our results indicate high Hg levels in samples of Lycoperdon perlatum (average 2.94 mg/kg DM) and in Lepista species (average 3.02 mg/kg DM). These data confirm the need for greater attention to be given to Hg levels in wild common mushrooms, especially to Hg-accumulating species. Received: 20 February 1997     

Antimicrobial activity and bioactive compounds of Portuguese wild edible mushrooms methanolic extracts

The antimicrobial properties of phenolic extracts of Portuguese wild edible mushroom species (Lactarius deliciosus, Sarcodon imbricatus and Tricholoma portentosum) against pathogens were investigated. The minimal inhibitory concentrations (MICs) were evaluated for the entire mushroom, the cap and the stipe, separately; the portion of the mushroom used proved to be influenced in the results obtained, which are directly correlated with the content of total phenols and flavonoids in the extracts. The growth of Gram-positive bacteria (Bacillus cereus, B. subtilis,) was well inhibited by these mushrooms, while Escherichia coli (Gram-negative bacteria) was resistant. The study on the antifungal effect of these mushrooms revealed that Candida albicans and Cryptococcus neoformans were differently inhibited for the mushrooms used.     

Chemical composition and non-volatile components of Croatian wild edible mushrooms

The chemical composition (dry matter, crude protein, crude fat, total carbohydrates, and ash) and non-volatile components content (soluble sugars, free amino acids, and 5′-nucleotides) of 10 popular Croatian wild edible mushroom species (Agaricus campestris, Boletus edulis, Calocybe gambosa, Cantharellus cibarius, Craterellus cornucopioides, Entoloma clypeatum, Flammulina velutipes, Macroleptiota procera, Morchella elata, and Pleurotus ostreatus) were determined. All investigated mushrooms were found to be good sources of proteins and total carbohydrates, with contents varying in the ranges of 27.95–38.89, and 42.62–66.78 g/100 g, respectively. In addition, the fat contents were very low 1.34–6.45 g/100 g. B. edulis (19.87 mg/g) showed the highest concentration of essential amino acids and M. elata (14.25 mg/g) the lowest concentration. Monosodium glutamate-like components and total flavour 5′-nucleotides were the highest in C. cornucopioides (45.85 and 13.88 mg/g, respectively), and lowest in F. velutipes (7.63 and 1.05 mg/g, respectively). Equivalent umami concentration values in 10 Croatian wild edible mushrooms ranged from 73.78 to 1186.45 g MSG/100 g dry weight, and overall, all these mushrooms possessed highly umami taste.     

Chemical composition and nutritional value of European species of wild growing mushrooms: A review

Numerous species of wild growing mushrooms are widely consumed as a delicacy in central and eastern Europe. Credible evaluation of their nutritional value has so far been limited due to fragmentary knowledge of their composition and mainly due to the very limited information on the availability of their constituents. Dry matter content is usually about 100 g kg⁻¹. Structural polysaccharides and proteins comprise the main components of dry matter, while the lipid content is low. Chitin, glycogen, mannitol and trehalose are typical carbohydrate constituents. The proportion of essential amino acids is nutritionally favourable, while the content of n−3 fatty acid is negligible. Low energy, high proportion of indigestible fibre, specific β-glucans and antioxidative and flavour constituents provoke the increasing interest of both researchers and consumers. The ability of some species to accumulate several detrimental trace elements and radiocaesium, and occurrence of detrimental constituents in edible mushrooms are also briefly reviewed.     

Nutritional value of edible wild mushrooms collected from the Khasi hills of Meghalaya

Seven wild edible mushrooms commonly consumed in the Khasi hills of Meghalaya were analyzed for their contents of dry matter, crude protein, fat, fibre and ash along with minerals (Ca, P, Fe, Mn, Cu, Zn, Na, K, Mg and Se), ascorbic acid and the profile of essential amino acids. The macronutrient profile in general revealed that the wild mushrooms were rich sources of protein and had low amounts of fat. In general, most of the mushrooms studied had good amounts of minerals, including trace minerals. On average, phenylalanine was the limiting amino acid (0.9 μg%) while the highest amount of EAA present in the mushrooms studied was leucine (704 μg%). One serving of the studied mushrooms (250 g fresh weight) contained an average of 6.12 g of protein, 287 mg of calcium, 9.3 mg of iron and 3.72 mg of zinc. More importantly it had low levels of fat (0.712 g) and sodium (0.077 mg).     

Fat and fatty acids of Indian edible mushrooms

Twenty-three species of naturally grown and collected mushroom fruiting bodies, from different geographic locations of India, were analysed for their total fat and fatty acid contents. On a dry weight basis, the mushroom species were found to contain 0.6–4.7% total fat. The mushroom species were high in unsaturated fatty acids (52–87%), compared to saturated fatty acids. Oleic acid was the major monounsaturated fatty acid in all the species studied, while linoleic acid was the major polyunsaturated fatty acid. Linolenic acid was in significant quantity in Hydnum repandum and Macrolepiota procera. Linoleic:oleic acid ratios of the mushroom species varied considerably (0.48–10.58).     

Free-radical scavenging capacity and reducing power of wild edible mushrooms from northeast Portugal: Individual cap and stipe activity

The antioxidant properties of two wild edible mushroom species from the northeast of Portugal, Lactarius deliciosus (L.) Gray and Tricholoma portentosum (Fr.) Quél., were evaluated. Methanolic extracts from the entire mushroom, the cap and the stipe, separately, were screened for their reducing power and free radical scavenging capacity by chemical assays. The total phenolic content was determined, in order to assess its effect on the extract’s antioxidant activity. Both two species showed antioxidant potential; but L. deliciosus proved to be more active. The portion of the mushroom used had an influence on the results obtained, with the cap methanolic extracts exhibiting the greatest antioxidant effect.     

Selenium contents of Portuguese commercial and wild edible mushrooms

The selenium contents of 66 mushroom samples, wild growing or commercially available in Portugal, fresh, canned or dried, were determined. The samples consisted of 18 mushroom species, mainly selected in accordance with their availability and consumer preference. The selenium contents varied considerably between different mushroom species. The highest selenium contents were found in the wild species Boletus aestivalis (48.5 mg/kg dry weight, DW), Boletus pinophilus (19.9 mg/kg DW), Boletus edulis (14.9 mg/kg DW), Boletus aereus (12.3 mg/kg DW), Boletus fragans and Boletus spretus (∼2 mg/kg DW). Other mushrooms having considerable selenium contents included Marasmius oreades (1.5 mg/kg DW), Agaricus bisporus “Portobello” (1.25 mg/kg DW), A. bisporus (1.0 mg/kg DW) and Russula cyanoxantha (0.72 mg/kg DW). The selenium contents of these mushrooms are sufficient to provide nutritionally significant amounts in relation to the total daily intake of selenium. Other edible mushrooms, such as Lentinula edodes, Pleurotus ostreatus, Cantharellus cibarius,Craterellus cornucopioides and Lepista nuda, contained only small amounts of selenium. The importance of these mushrooms as a source of selenium is therefore marginal.     

Comparative study of phytochemicals and antioxidant potential of wild edible mushroom caps and stipes

A comparative study of the organic acids and phenolics composition and of the total alkaloids content of entire wild edible mushrooms (Russula cyanoxantha, Amanita rubescens, Suillus granulatus and Boletus edulis) and correspondent caps and stipes was performed. All species presented oxalic, citric, malic and fumaric acids, with A. rubescens exhibiting the highest total organic acids content. Organic acids were preferably fixed in the cap. Among phenolics, only p-hydroxybenzoic acid was found in A. rubescens and S. granulatus, in very low amounts. B. edulis was the species that presented the highest total alkaloid amounts. Except for this species, alkaloids mainly accumulated in the cap. All of the species exhibited a concentration-dependent scavenging ability against DPPH^·. B. edulis revealed the highest antioxidant capacity. The cap seemed to be the part with highest antioxidant potential. Some relationships between chemical composition and antioxidant capacity were considered.     

Mineral and trace metal levels in some cheese collected from Turkey

Concentrations of elements (Fe, Mn, Zn, Cu, Pb, Cr, Ni, Na, K, Ca and Mg) in cheese samples were analyzed using flame and graphite furnace atomic absorption spectrometry after microwave digestion. The order of levels of the elements in the samples was determined to be Na > Ca > K > Mg > Zn > Fe > Pb > Mn > Cr > Ni. The concentration ranges in the samples were found to be 4.1–12.5, 0.28–1.1, 8.8–13.2, 0.10–0.27, 0.14,–1.2, 0.02–0.62, 0.18–0.34, 3957–6558, 305–362, 3473–4556 and 28.9–127 μg/g for iron, manganese, zinc, copper, lead, chromium, nickel, sodium, potassium, calcium and magnesium, respectively. High trace metal and mineral accumulation levels in the samples were found in Van otlu cheese for Fe, Ordu çerkez cheese for Na, Kayseri çömlek cheese for Mn, Pb, Çeçil cheese for Zn, Kars ka?ar cheese for Cu, Cr, Tokat cheese for Ni, Ca and Erzincan tulum cheese for K, Mg, respectively.     

Nutritional contents of three edible oyster mushrooms grown on two substrates at Haramaya,Ethiopia, and sensory properties of boiled mushroom and mushroom sauce

The effects of wheat and bean straw growing substrates on nutrient contents of three edible oyster mushrooms and sensory properties of two mushroom foods were investigated. Moisture (fresh weight basis), crude protein, fat, fibre, ash, total carbohydrate, Fe, P and Zn (db) were ranged: 85.18–88.86%, 30.04–37.63%, 1.61–2.55%, 9.33–13.29%, 6.83–9.38%, 29.68–32.53%, 4.86–5.66 mg per 100 g, 12.39–15.36 g kg^?1 and 54.61–65.98 mg kg^?1, respectively. Moisture, fat and fibre were significantly (P < 0.01) affected by substrates, species and their interactions. Substrates showed no differences on ash, Fe and P (P > 0.05). Protein content was high for mushrooms grown on bean straw. Pleurotus sajor‐caju grown on bean straw had high protein, ash, Fe and P contents. No significant (P > 0.05) sensory acceptability differences were observed for boiled mushroom and mushroom sauce except colour of boiled mushrooms. In Ethiopia, if mushroom consumption is popularised, the support for food nutrition security is substantial.     

Comparative study of antioxidant and antibacterial properties of the edible mushrooms Pleurotus levis,P. ostreatus,P. pulmonarius and P. tuber‐regium

Comparative studies of functional properties among closely related mushroom species, supported by molecular identification, standard cultivation and extraction protocols, are not well documented. We compared antioxidant and antibacterial properties of standardised hydroalcoholic extracts of four Pleurotus species (P. levis, P. ostreatus, P. pulmonarius and P. tuber‐regium). Antioxidant properties were investigated using DPPH and ABTS radical scavenging capacity, total phenolic content, β‐carotene‐linoleic and ORAC assays. Antibacterial effect was assessed using the microplate method. The functional properties of standardised mushroom extracts were different in species studied. β‐carotene–linoleic acid and ORAC assays showed high antioxidant activity, particularly in P. ostreatus. Pleurotus tuber‐regium exhibited the lowest antioxidant activity in the ORAC assay (3316.0 μmol of trolox equivalent mL^?1), but exerted the most potent bacteriostatic and bactericidal activity. Bacillus subtilis showed a high degree of susceptibility to a very low concentration (3.33 μg mL^?1) of P. levis extract. Remarkable antioxidant and antibacterial properties were found in P. levis and P. tuber‐regium compared to the other species studied that are cultivated commercially.     

Determination of trace metal levels in sediment and five fish species from lakes in Tokat,Turkey

In this study, concentrations of trace metals in five fish species (Cyprinus carpio, Capoeta tinca, Leiciscus cephalus, Carassius gibelio and Silurus glanis) and sediments collected from some lakes in Tokat were determined by atomic absorption spectrometry. The fish species and sediment samples were collected from six lakes (Bedirkale, Boztepe, Belp?nar?, Avara, Ataköy and Ak?n) in Tokat, Turkey in spring and summer during 2003–2004. The samples were digested with a microwave digestion system. The maximum Fe, Mn, Zn, Cu, Pb, Cr and Ni concentrations of sediment samples were 2138, 232, 38.9, 8.2, 7.0, 10.7 and 55.4 μg/g, respectively. The maximum Fe, Zn, Cu, Pb, Cr, Mn and Ni concentrations of the fish samples were 167, 48.6, 3.6, 2.8, 1.6, 64.3 and 5.6 μg/g, respectively.     

Lipids classes, fatty acids and carotenes of the leaves of six edible wild plants

 α-Linolenic acid and unusual fatty acids of the ω3 and ω6 series play an important role in the modulation of human metabolism. The presence of these acids in the leaves of several edible wild plants has recently been reported. In this study, six edible wild species were selected in order to establish the fatty acid compositions in their leaf lipids. Thus, young leaves from Amaranthus viridis L.(blet), Chenopodium album L. (goosefoot), Crithmum maritimum L. (rock samphire), Plantago major L. (plantain), Portulaca oleracea L. (purslane) and Verbena officinalis L. (vervain) yielded 1.50, 2.20, 3.02, 1.46, 3.81, and 2.28 g of lipids per 100 g dry plant material. Silica gel chromatography yielded 0.64 g (Plantago major) to 2.19 g (Crithmum maritimum) neutral lipids, 0.37 g (Plantago major) to 1.60 g (Portulaca oleracea) glycolipids, and 0.26 g (Crithmum maritimum) to 0.57 g (Verbena officinalis) phospholipids per 100 g (dry weight). Gas chromatography (GC) showed the major fatty acids to be 18 : 3ω3, 18 : 2ω6 and 16 : 0 in all fractions, with high concentrations of 18 : 3ω3 in the glycolipid fraction. GC-mass spectrometric analyses did not reveal the presence of unusual fatty acids. Carotenes were found in high concentrations, ranging from 30.5 mg/100 g (Chenopodium album) to 89.2 mg/100 g (Portulaca oleracea). The analyzed plants are rich sources of essential fatty acids (18 : 2ω6 and 18 : 3ω3) and also of carotenes. Received: 29 October 1998     

Carcass characteristics,meat quality and nutritional value of horsemeat: A review

Meat has exerted a crucial role in human evolution and is an important component of a healthy and well balanced diet due to its nutritional richness. The aim of the present review was to shed light on the nutritional composition of horsemeat and their benefits for human health. One of the reasons for such interest was the occurrence, in Europe several years ago, of dioxin, Bovine Encephalopathy and foot-and-mouth disease problems in farm animals. Therefore, consumers began to look for alternative red meats from other non-traditional species. There is no carcass classification system on horses designated to meat consumption. It would be advisable to standardize the equine meat market to reduce variations that may reflect differences in meat quality. The nutritional composition of horsemeat by comparison with pork, beef or poultry is characterized by low levels of fat and cholesterol (about 20% less), relatively high concentrations of n− 3 fatty acids and heme iron indicating that its consumption may be beneficial for health. Therefore, horsemeat may supplement the meat market with good quality products, although as in other dietary components moderation is advisable.     

Trace metal content in nine species of fish from the Black and Aegean Seas,Turkey

Trace metal content of nine fish species harvested from the Black and Aegean Seas were determined by microwave digestion and atomic absorption spectroscopy (MD–AAS). Verification of the MD–AAS method was demonstrated by analysis of standard reference material (NRCC-DORM-2 dogfish muscle). Trace metal content in fish samples were 0.73–1.83 μg/g for copper, 0.45–0.90 μg/g for cadmium, 0.33–0.93 μg/g for lead, 35.4–106 μg/g for zinc, 1.28–7.40 μg/g for manganese, 68.6–163 μg/g for iron, 0.95–1.98 μg/g for chromium, and 1.92–5.68 μg/g for nickel. The levels of lead and cadmium in fish samples were higher than the recommended legal limits for human consumption.     

Nutritional value and antioxidant capacity of lunch meals consumed by elderly people of Sharpeville,South Africa

The main objective of this study was to determine the nutritional value and the total dietary antioxidant capacity (TDAC) of lunch meals consumed by elderly people attending a day-care centre in Sharpeville, South Africa. Meals were monitored and collected for a two-week period. The menus were analysed for water, ash, fat, protein, carbohydrates, polyphenols and antioxidant capacity. Eighteen food items, grouped in seven different menus, were identified. Energy provided by the menus covered 32% of the daily reference intakes for females and 25% for males, and the distribution of macronutrients in the menus was 10%, 34% and 56% for protein, fat and carbohydrates, respectively. This is close to the prescribed acceptable macronutrient distribution ranges of 10–35% protein, 20–35% fat and 45–65% carbohydrates. TDAC available from the menus was estimated at 332 μmol Trolox equivalents by DPPH (2,2′-diphenyl-1-picrylhydrazyl) and represented about 9% of the recommended daily allowance. Fruit, which represented only 2.8% of the amount of foods composing the menus, supplied 75.3% of TDAC, whilst contributions from vegetables and legumes were low. With 269 mg gallic acid equivalent in the menus, total phenolics appeared to be quantitatively the main dietary antioxidant, and were significantly correlated (r = 0.443 and p = 0.007) with antioxidant capacity. Fruit portions of the meals served by the day-care centre to the elderly of Sharpeville, need to be increased and diversified in order to reinforce their intake of antioxidants and thus reduce the incidence of non-communicable diseases.