Abstract: In this study, the volatile components of sweet fermented oat produced by natural and inoculated fermentation were analyzed and compared by headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that totally 62 and 65 volatile compounds were detected in the samples from natural and inoculated fermentation, respectively, mainly including acids, esters, alcohols, aldehydes and ketones, heterocyclic compounds and hydrocarbons. Using principal component analysis (PCA), esters, alcohols and heterocycles were found to be positive volatile components. The major volatile aroma components of the second sample were alcohols (58.31%), esters (20.70%) and acids (16.75%), while the major volatile aroma components of the first sample were acids (61.94%), esters (18.89%) and alcohols (13.58%). The contents of esters, alcohols, and heterocycles in inoculated fermentation were significantly higher than those in natural fermentation, whilst the opposite was true for acids. The results of this study should be helpful to determine the feasibility of applying inoculated fermentation for producing sweet fermented oat and should provide a theoretical basis for the quality evaluation and production of sweet fermented oat in the future.

Key words: sweet fermented oat; inoculated fermentation; natural fermentation; volatile components; principal component analysis