engleski

Vibrational spectroscopic characterization of mushrooms

We have collected and identified several dozens of different mushroom species, mainly belonging to Basidiomycetes and Ascomycetes species. Some healthy specimens were left to dry in the stream of the air for several hours, while from others we collected the spores. FTIR spectra were recorded with 580B Perkin-Elmer instrument. The spore powder was pressed in the KBr disc. The method of KBr pellets is known to be less suitable for humic, fresh mushroom flesh, but spores have proved to be more stable and not to decompose. In Fig 1. we compare the spectra of 1 - Amanita citrina, 2 - Amanita strobiliformis, 3 - Russula cyanoxantha and 4 - Russula heterophylla. The sharp band at 1748 cm-1 belongs to C=O stretching from esters, and the broad band at 1650 cm-1 is the Amide I band. The adjoint broad but weaker band at 1550 cm-1 is the Amide II band. The amide bands originate from peptide bonds C=ONH present. Here they either originate from the N-acetylglucosamine which is the repeating unit of chitin, or from proteins. The "fingerprint region" of the mushroom species is definitely the interval from1000-1200 cm-1. The dominant bands present are from C-C and C-O inside glucose rings, as well as from C-O-C stretching from the glycosidic bond. The cellulose has its strongest bands in this region, as well as all glucans. No estimate could be made on the amount of each compound, but remarkable similarity in the spectra appear between mushrooms genus Amanita, as well as between different Russula species. The spores of Boletus and Xerocomus also show great similarities.

mushrooms; infrared spectroscopy

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