Pleurotus Mushrooms Content in Glucans and Ergosterol Assessed by ATR-FTIR Spectroscopy and Multivariate Analysis

Abstract

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to monitor the infrared absorption spectra of 79 mushroom samples from 29 Pleurotus ostreatus, P. eryngii and P. nebrodensis strains cultivated on wheat straw, grape marc and/or by-products of the olive industry. The spectroscopic analysis provided a chemical insight into the mushrooms examined, while qualitative and quantitative differences in regions related to proteins, phenolic compounds and polysaccharides were revealed among the species and substrates studied. Moreover, by using advanced chemometrics, correlations of the recorded mushrooms’ spectra versus their content in glucans and ergosterol, commonly determined through traditional analytical techniques, allowed the development of models predicting such contents with a good predictive power (R2: 0.80–0.84) and accuracy (low root mean square error, low relative error and representative to the predicted compounds spectral regions used for the calibrations). Findings indicate that FTIR spectroscopy could be exploited as a potential process analytical technology tool in the mushroom industry to characterize mushrooms and to assess their content in bioactive compounds.

Application of Near-Infrared Spectroscopy to Investigate Some Endogenic Properties of Pleurotus ostreatus Cultivars

“…Free radical scavenging activity DPPH value [2,7,[14][15][16][17][18][19], FRAP value [2,19,20] Total polyphenol content Folin Ciocalteu method [2,[17][18][19] Active antioxidant polysaccharides HPLC [15] Amino acid content HPLC with fluorescence detector [2,[21][22][23][24][25][26] Glucans and ergosterol ATR-FTIR [7,8] Strain classification and taxa delimitation FT-IR [27] Identifying bioactive compounds ATR-FTIR [27] Antioxidant activity DPPH value and FTIR [28] Water soluble polysaccharides FTIR [29] Phylogenetic relatedness-DNA FTIR [30] DPPH: 2,2-diphenyl-1-picryl-hydrazyl; FRAP: Ferric Reducing Ability of Plasma; ATR-FTIR: Attenuated total reflection Fourier-transform infrared spectroscopy; FT-IR: Fourier-transform infrared spectroscopy.…”

“…Synergistic effect of these molecules may stimulate the free radical scavenging activity of these mushrooms [6]. Reducing components (phenolics and polyphenolics) [7,8] of mushrooms are formed during secondary metabolic processes that inhibit or delay the effects of oxidative damage and are involved in protection against free radicals [9][10][11].…”

Volatile Profiling of Pleurotus eryngii and Pleurotus ostreatus Mushrooms Cultivated on Agricultural and Agro-Industrial By-Products

“…Literature data consider temperatures around 120-130 • C as optimal for the formation of Maillard reaction products with favorable sensory characteristics [68] as well as for the formation of compounds with sulfur and nitrogen groups [69,70], e.g., pyrazines, Strecker aldehydes, dimethyldisulfide and pyrrole (detected in the roasted Pleurotus samples; Table 3). It is noteworthy that Pleurotus mushrooms contain significant amounts of Maillard reaction precursors, namely free amino acids, reported to comprise 37.1-41.6% of crude protein [44] and glucans, which comprise 40-50% w/w of the total content on a dry weight basis [71]. In addition, the Strecker aldehydes 2-methylbutanal, 3-methylbutanal, methional, phenylacetaldehyde and benzaldehyde, detected in the roasted samples (Table 3) derive from isoleucine, leucine, methionine and phenylalanine [67,72], i.e., amino acids that are present in the mushrooms studied [44].…”

Advances of Spectrometric Techniques in Food Analysis and Food Authentication Implemented with Chemometrics

“…Finally, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used by Bekiaris et al [9] to monitor the infrared absorption spectra of mushroom samples from Pleurotus ostreatus, Pleurotus eryngii, and Pleurotus nebrodensis strains, cultivated on wheat straw, grape marc and/or by-products of the olive industry. The spectroscopic analysis provided a chemical insight into the mushrooms examined, while qualitative and quantitative differences in regions related to proteins, phenolic compounds, and polysaccharides were monitoredamong the species and substrates studied.…”