Abstract: In order to enrich the deep-processing theory of dairy fan and provide technical support and a theoretical guideline for the industrial production of dairy fan, gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O) and fast gas chromatography-based electronic nose (fast?GC E-nose) were used to explore the effects of three processing methods including microwaving, frying and baking on the flavor of dairy fan in the present study. The correlation between sensory attributes and characteristic aroma compounds was also analyzed by partial least squares discriminant analysis (PLS-DA). The results showed that compared with the raw sample, microwave treatment led to a significant enhancement in the sour taste. Frying and baking caused a decrease in the overall aroma intensity but resulted in the formation of rich caramel-like and nutty aromas. All samples could be clearly distinguished by the electronic nose. A total of 67 volatile compounds were detected by HS-SPME-GC-MS in the four samples. In addition, 15, 16, 20, and 21 characteristic aroma compounds were identified through GC-O analysis and odor activity value (OAV) calculation. The contents of acidic compounds increased after microwave treatment. Although the flavor compounds reduced obviously after frying and baking, Maillard and caramelization reaction products occurred. PLS-DA analysis showed the correlations between seven sensory attributes and 19 characteristic aroma compounds. 2-Methylbutanal, 3-methylbutanal, 2-methylpyrazine and furfural played an important role in the formation of the caramel-like aroma of fried or baked dairy fan.

Key words: processing methods; dairy fan flavor; gas chromatography-mass spectrometry; gas chromatography-olfactometry; electronic nose