Abstract: Roast Tan sheep (an indigenous breed in Yanchi County, Ningxia Hui Autonomous Region) meat adulterated with duck meat and pure roast sheep meat were discriminated by an electronic nose. Their volatile composition was analyzed by headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and chemometrics. The results showed that a total of 53 volatile compounds were identified in five adulterated samples, including 12 alcohols, 15 aldehydes, 3 acids, 2 esters, 8 ketones, 8 alkanes, 1 heterocyclic compound and 4 other compounds. Principal component analysis (PCA) clearly distinguished the electronic nose data for the overall odor of adulterated roast mutton samples, and showed that the major differential volatile compounds were alcohol compounds. By partial least squares discriminant analysis (PLS-DA), five characteristic volatile substances were found in adulterated samples, namely 1-octanol, 1-pentanol, hexanal, acetic acid, and dodecane, which will be useful to determine the level of duck meat in adulterated roast mutton samples.

Key words: roast lamb meat; roast duck meat; adulteration; electronic nose; gas chromatography-mass spectrometry; chemometrics; partial least squares discriminant analysis