Effect of immobilized Lactobacillus casei on the evolution of flavor compounds in probiotic dry-fermented sausages during ripening.

The effect of immobilized Lactobacillus casei ATCC 393 on wheat grains on the generation of volatile compounds in probiotic dry-fermented sausages during ripening was investigated. For comparison reasons, sausages containing free L. casei cells or no starter culture were also included in the study. Samples were collected after 1, 28 and 45days of ripening and subjected to SPME GC/MS analysis. Both the probiotic culture and the ripening process affected significantly the concentration of all volatile compounds. The significantly highest content of total volatiles, esters, alcohols and miscellaneous compounds was observed in sausages containing the highest amount of immobilized culture (300g/kg of stuffing mixture) ripened for 45days. Principal component analysis of the semi-quantitative data revealed that primarily the concentration of the immobilized probiotic culture affected the volatile composition.