Abstract:Headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and electronic nose were used to determine the volatile components of yam slices processed by hot-air drying (HAD), microwave drying (MD), vacuum drying (VD), vacuum freeze-drying (VFD) and combined drying. The effects of drying processing on the flavor of yam slices were studied by principal component analysis. The results showed that a total of 95 kinds of volatile substances were detected in these five dried products. And hydrocarbons, aldehydes, ketones, alcohols, esters, benzene and heterocyclic compounds were the main components. Nonanal, decanal, 2,6,10-trimethyl-tetradecane and geranyl acetone were the main volatile substances in yam slices. The main volatile substances in yam slices processed by HAD, VD and MD were hydrocarbons, benzene and aldehydes, while the main volatile substances of VFD or VFD-HAD dired yam slices were hydrocarbons, aldehydes and ketones. The electronic nose detection showed that the aroma of yam slices was affected by drying methods. The aroma of yam slices processed by HAD and VD were similar in alcohol and some aromatic compounds. The aroma differences of yam slices between VFD and other drying methods were mainly nitrogen oxides and sulfur compounds. These were consistent with GC-MS analysis. On the basis of principal component analysis, the evaluation model of aroma quality was established. Considering the comprehensive score and aroma quality of yam slices, combined drying were the best drying method, followed by VFD, MD, HAD and VD.