Analysis of Flavor Components from the Different Grade Traditional Pixian Bean Pastes by Simultaneous Distillation-extraction and GC-MS

The volatiles from the three grade traditional Pixian beans were extracted by simultaneous distillation-extraction (SDE), using methylene chloride as a solvent. The volatiles were isolated and identified by gas chromatography-mass spectrometry (GC-MS) technique. The results showed that the identified 109 volatiles from three grade Pixian Bean Pastes mainly included esters, alcohols, aldehydes and ketones. The relative content of methyl oleate, isoamylol, phenethyl alcohol, isovaleraldehyde from superior-level Pixian Bean Paste, highly reached 14.54%, 10.34%, 3.54% and 8.30%, respectively, and 2-Hydroxy-3-pentanone level as high as 12.25% was only detected in this grade paste. Methyl oleate, isoamylol, linalool, isovaleraldehyde, 4-ethyl-2-methoxy phenol from the first-level Pixian Bean Paste were found to be high relative content, reaching 8.27%, 4.96%, 1.57%, 3.07% and 3.56% respectively. The second-level Pixian Bean Paste with relatively higher amounts ethyl acetate (15.22%), isoamylol (4.73%), 2-methyl propioric acid (1.21%), isovaleraldehyde (4.20%).