Oat flour fermented by Lactobacillus strains – Kinetics of volatile compound formation and antioxidant capacity

Oat flour (Avena sativa L.) was fermented for 24 h with selected Lactobacillus strains: L. plantarum W42, L. plantarum IB, and L. casei LcY. The highest number of colony-forming units was determined between the 16th and 18th hour of oat fermentation and was positively correlated with sample acidifying activity. The 8–14 h oat fermentation with both L. plantarum strains, but not with L. casei LcY, led to obtaining products with stronger antioxidant properties. Forty-four volatile compounds were detected in fermented oat samples with aldehydes as the major group of molecules, followed by alcohols, ketones, and acids. In the case of L. plantarum W42, the highest content and number of volatiles was formed after 12 h of fermentation, while L. plantarum IB and L. casei LcY needed 20 h to this end. Generally, the composition and concentration of volatile compounds of fermented oat were strain-dependent. The results obtained provide useful information for the further development of new functional oat products.