Characterisation of flavour and taste compounds in Agaricus blazei murrill sensu Heinem., the cultivated almond mushroom.

Agaricus blazei Murrill sensu Heinem. is a new cultivated medicinal and gourmet mushroom which is currently popular in Brazil, Japan and China. It is also cultivated in the USA, and it has recently drawn the attention of European mushroom growers. Upon investigating the mushroom's pleasant almond flavour, it was observed that benzaldehyde and its precursor benzoic acid were the major components of the volatile fraction. Other benzylic compounds contributing to the flavour were benzyl alcohol, methyl benzoate and 4-hydroxybenzaldehyde. When reconstituting the commercially available dried mushrooms, almond flavour develops, presumably by enzymic conversion of benzoic acid to benzaldehyde and benzyl alcohol. Since benzoic acid is present at concentrations of 1280-3100 mg/kg dry weight, it may contribute to the excellent shelf life of the mushroom. Interestingly, benzoic acid also occurs in several close relatives of A. blazei, suggesting that this compound could well be a taxonomic marker. Among the non-volatile taste compounds, mannitol predominated to the extent of 22% on dry weight. Contents of taste-enhancing free glutamic and aspartic acids were comparable to those reported in the White button mushroom (Agaricus bisporus). The mycelium of A. blazei was found to be poor in nearly all compounds investigated. No almond flavour was observed and its crude protein content was only 13% compared with an average value of 30% in the dried mushrooms. Moreover, it had less than 1% of mannitol and only very low levels of free amino acids. Typical secondary metabolites as urea, free tryptophan and agaritine were even totally absent.Resumo

Multivariate analysis of mineral constituents of edible Parasol Mushroom (Macrolepiota procera) and soils beneath fruiting bodies collected from Northern Poland

Caps and stipes of 141 fruiting bodies of Parasol Mushroom (Macrolepiota procera) and surface layer of soils collected from 11 spatially distant and background (pristine) areas in Northern Poland were analyzed for Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, and Zn by inductively coupled plasma optical emission spectroscopy and cold vapor atomic absorption spectroscopy. In terms of bioconcentration and bioexclusion concept, K, Ag, Cu, Rb, and P were highly bioconcentrated in caps, and their bioconcentration factor values varied for the 11 sites between 120 and 500—67–420, 70–220, 10–170, and 45–100, respectively. Cd, Zn, Mg, and Na showed bioconcentration factors (BCFs) between 3.3 and 36, 3.7–15, 0.92–6.3, and 1.4–44 while Al, Ba, Ca, Co, Cr, Mn, Ni, Pb, and Sr were excluded (BCF < 1). The Parasol Mushroom is a species harvested in the wild, and its caps are of unique taste and can contain a spectrum of essential and hazardous mineral compounds accumulated at elevated concentrations, even if collected at the background (pristine) areas. These elevated mineral concentrations of the caps are due to the efficient bioconcentration potential of the species (K, Ag, Cu, Rb, P, Cd, Zn, Mg, and Na) and abundance in the soil substrates (Al, Ca, Fe, Mn). The estimated intake rates of Cd, Hg, and Pb contained in Parasol Mushroom’s caps show a cause for concern associated with these metals resulting from the consumption of between 300- and 500-g caps daily, on a frequent basis in the mushrooming season

Selenium uptake and associated anti-oxidant properties in Pleurotus fossulatus cultivated on wheat straw from seleniferous fields

The present study was carried out to examine the antioxidant activity in oyster mushroom cultivated on selenium (Se) rich substrate. Pleurotus fossulatus was cultivated on Se-rich wheat straw collected from the seleniferous belt of Punjab (India) and its potential to accumulate Se from substrate was examined. Using different assay systems the modulations in the anti-oxidant profile of Se enriched mushroom was studied in comparison to the mushrooms cultivated on normal straw. The oyster mushrooms were observed to potentially mobilize Se from Se-rich substrates to fruiting bodies, resulting in significantly high uptake (37.2±0.6 μg g−1) as compared to control (3.57±0.53 mg g−1). The antioxidant activity, as determined by various assays, such as reducing power, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, and metal chelating activity, was higher in the experimental mushrooms when compared to control. The results obtained demonstrate that Se-fortified mushrooms through cultivation on straw containing organic forms of Se can be considered as natural and effective dietary supplements of organic Se for humans. The present study proposes the use of Se-rich agricultural residues as substrates for mushroom cultivation for human and livestock supplementation

Absence of psilocybin in species of fungi previously reported to contain psilocybin and related tryptamine derivatives

Seven taxa of agarics reported in literature to contain psilocybin (viz. Psathyrella candolleana, Gymnopilus spectabilis, G. fulgens, Hygrocybe psittacina var. psittacina and var. californica, Rickenella fibula, R. swartzii) have been analysed for psilocybin and related tryptamines with negative results

Occurrence of Psilocybin and Baeocystin in the genus Inocybe (Fr.) Fr

The presence of psilocybin and its monomethyl analogue baeocystin is for the first time demonstrated in five taxa of the genus Inocybe, viz. I. coelestium, I. corydalina var. corydalina, I. corydalina var. erinaceomorpha, I. haemacta and I. aeruginascens. These taxa are characterized by a glaucous coloration of the stipe. A sixth taxon, I. calamistrata, which also has a blue-green stipe was found to be exempt of psilocybin and other methylated tryptamines. Negative results were also obtained for other Inocybes. Muscarin is absent in the psilocybincontaining species. However, no relation between taxonomic position and the presence of either compound seems to exist