Researchers have used several analytical techniques to examine how flavor-related chemicals vary among five species of edible bolete mushroom. The findings could support mushroom identification, quality control, and the assessment of food products.
The study, published in npj Science of Food, examined Boletus bainiugan, Butyriboletus roseoflavus, Rugiboletus extremiorientalis, Lanmaoa asiatica, and Phlebopus portentosus. Researchers collected 82 mushroom fruiting bodies from southwest China and prepared 30 combined samples, with six biological replicates for each species.
Mushroom flavor is shaped by nonvolatile compounds, which contribute to taste, and volatile compounds, which produce aroma. The researchers used liquid chromatography-tandem mass spectrometry to measure amino acids and organic acids. They also used headspace solid-phase microextraction gas chromatography-mass spectrometry to analyze volatile compounds.
The analysis identified 68 amino acids and related metabolites, 57 organic acids, and 773 volatile compounds. Statistical analysis separated the samples according to species, showing that each had a distinct chemical profile.
The researchers compared compound concentrations with previously published taste and odor thresholds to estimate which chemicals were most likely to affect flavor. Glycine, arginine, aspartic acid, lysine, and fumaric acid were among the main compounds distinguishing the mushrooms’ taste profiles. Sweet and umami amino acids made the largest contribution.
Six volatile compounds were selected as possible markers of aroma differences. These included pyrazines, an ester, an aldehyde, and a furanone associated with roasted, nutty, fruity, floral, and mushroom-like odors.
Pathway analysis suggested that differences in amino acids and organic acids may be linked to the tricarboxylic acid and urea cycles. However, these metabolic relationships were inferred from the chemical profiles and were not confirmed using gene expression or enzyme activity studies.
The team also used computer modeling to predict how the aroma compounds might interact with human odor receptors. Several compounds showed predicted binding to the receptor OR1A1. These results provide possible explanations for odor perception but do not confirm how people experience the mushrooms’ aromas.
For more rapid testing, the researchers combined attenuated total reflectance Fourier-transform infrared spectroscopy with machine learning. The strongest model predicted concentrations of selected flavor compounds with coefficients of determination of at least 0.95.
This approach could provide a faster initial screen for species identification and product quality, while mass spectrometry could supply more detailed chemical measurements. However, the study included a limited number of samples and collection sites. Differences in habitat may have influenced the chemical profiles.
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