Abstract: In order to explore the difference in the volatile components of different varieties of roasted, gas chromatographymass spectrometry (GC-MS) was used to separate and identify the volatile components of 10 different varieties of roasted hulless barley. The influence of roasting on the flavor of the variety Kunlun 15 was examined, and then different varieties of roasted hulless barley were classified by using aroma analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that a total of 140 aroma components were detected in all samples, including 32 heterocyclics, 26 esters, 21 alcohols, 19 aldehydes, 16 ketones, 13 acids, 9 hydrocarbons and 4 nitriles. After roasting, the number of aroma components of Kunlun 15 increased from 48 to 60, and the newly formed aroma components were mostly pyrazines. The most abundant aroma substances were geterocycles (38.59%–64.42%) in all hulless barley varieties, followed by esters (1.85%–35.98%) and aldehydes (7.56%–21.79%). Aroma analysis showed that the flavor of roasted hullness barley was dominated by cocoa-like, roasted and nutty aromas, while raw hullness barley from Kunlun 15 had a strong fruity and sweet aroma. The aroma of roasted hulless barley was related to variety and chemical composition, and Dulihuang might be the most suitable variety for processing of roasted barley. Cluster analysis showed that the samples could be classified into two categories. Kunlun 15 and Zangqing 320 were plotted as one class due to their high similarity. The other varieties could be classified into the other group when the euclidean distance was 9.

Key words: hulless barley, roasting, volatile flavor, gas chromatography-mass spectrometry (GC-MS), hierarchical cluster analysis (HCA), principal component analysis (PCA)