[Screening key odor biomarkers in different processed products of Atractylodis Rhizoma by HS-GC-IMS combined with...

To explore odor differential biomarkers in different processed products of Atractylodis Rhizoma, this research took three processed products raw, bran-fried, and rice-water processed Atractylodis Rhizoma as research objects. The volatile components were detected by using headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS), with qualitative identification via NIST 2020 and IMS databases. Odor differences among the processed products of Atractylodis Rhizoma were compared by using fingerprint similarity evaluation and partial least squares discriminant analysis(PLS-DA), while the odor differential biomarkers were screened through analysis of variance, variable importance projection(VIP), relative odor activity value(ROAV), and principal component analysis(PCA). The results show that a total of 83 chromatographic peaks and 47 compounds are identified, with terpenoids, acids, and alcohols as the primary shared volatile components in these three processed products of Atractylodis Rhizoma. After the raw Atractylodis Rhizoma was stir-fried with bran, the relative contents of alcohol components were significantly decreased, while the relative contents of aldehyde, ester, and heterocyclic components were increased. Especially, the contents of Maillard reaction products such as 2-methylbutanal, 3-methylbutanal, and furfural were significantly increased, resulting in a burnt aroma. After rice-water processing, the relative contents of terpenoid components were significantly decreased, while those of aldehyde and ester components were significantly increased. Fingerprint spectra reveal variations in the signal peak response concentrations of volatile components across different processed products of Atractylodis Rhizoma. Accordingly, raw, rice-water-processed, and bran-fried Atractylodis Rhizoma could be clearly clustered and distinguished in the two-dimensional scatter plots of PLS-DA and PCA. By taking VIP>1.0, P<0.05, fold change(FC)>1.2 or FC<0.83, and ROAV>1 as comprehensive indicators, eight key odor differential biomarkers including methyl salicylate, linalool, butanal, 3-methylbutanal, 2-methylbutanal, α-pinene, hexanal, and pentanal were identified, providing a chemical basis for revealing the processing mechanism of Atractylodis Rhizoma.