Comparison of key aroma active compounds in fresh and hot air dried Agaricus blazei by molecular sensory methods

The unique flavor of Agaricus blazei (A. blazei) has led to its high popularity among consumers. In this study, molecular sensory science methodologies were employed to characterize the aroma profiles and to identify the key aroma active compounds (AACs) present in both fresh A. blazei (FA) and its dried counterpart (DA). According to the sensory evaluation results, the nutty, toasted, and smoky notes of A. blazei were significantly enhanced after hot air drying (HAD), whereas the fresh mushroom, earthy, and grassy notes were markedly reduced. A total of 66 AACs were identified through comprehensive two-dimensional gas chromatography × gas chromatography-olfactometry-time-of-flight mass spectrometry (GC × GC-O-TOF MS) combined with aroma extract dilution analysis (AEDA). The key AACs were further confirmed by aroma recombination and omission tests: 5 key AACs were characterized in FA, primarily comprising 1-octen-3-ol, 3-octanol, and octanal. By comparison, up to 15 key AACs were determined in DA, among which 2-amylfuran, 3-methyl-butanal, furfural, and γ-nonanolactone were found to be the predominant contributors. It was demonstrated that HAD fundamentally reshapes the aroma signature of A. blazei by degrading C8 compounds and promoting the generation of Maillard reaction products and lipid oxidation derivatives. The molecular basis for the aroma differences between FA and DA was elucidated by this study, providing a theoretical foundation for the regulation of flavor quality in dried products.