Abstract: In this study, Lactobacillus fermentum C2-8, which is able to produce high α-galactosidase activity, was used as a starter culture in chickpea sourdough fermentation. The effect of the starter culture on the contents of organic acid, raffinose, stachyose, reducing sugar, and free amino acid in chickpea sourdough as well as on its breadmaking characteristics was evaluated using solid phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS), a texture analyzer, an electronic tongue, and sensory evaluation. The results showed that chickpea sourdough fermented for 24 h contained 62.67 and 15.53 mmol/kg lactic acid and acetic acid, respectively; raffinose and stachyose in it were completely degraded, and the content of reducing sugar was 11.50%. The content of total free amino acid increased 1.26 times when compared to unfermented dough. Compared with chickpea bread (CB), the specific volume of chickpea sourdough bread (CSB) increased (P < 0.05) by 4.60%, while the hardness, and chewiness decreased by 18.49%, and 15.64%, respectively. The peak areas of volatile flavor compounds including alcohols, acids, esters and ketones in CSB markedly increased compared to CB. Interestingly, the peak area of phenylethanol was 2.04 times higher in CSB than CB. Tastes scores of sweetness, sourness, umami, and saltiness and overall flavor characteristics were improved in CSB than CB. Scores for all quality characteristics except color were higher in CSB than CB, with the former having a score for overall acceptability of 7.2 points.

Key words: α-galactosidase; chickpeas; sourdough; raffinose; flavor; texture