EFFECT OF TEMPERATURE AND PRESENCE OF Saccharomyces cerevisiae ON THE ACIDIFICATION PERFORMANCES AND ELECTRONIC NOSE PROFILE OF Pediococcus spp. STRAINS ISOLATED FROM HAMOUM

The aim of this study was to evaluate the fermentation and aromatic potential of indigenous strains of Pediococcus spp., isolated from a traditional Algerian cereal-based product, the Hamoum, and applied to cereal doughs, with or without Saccharomyces cerevisiae and at 25 and 30°C. Pediococci reached cell densities of 9-10 log CFU/mL and showed significant acidification, although with different profiles in terms of acidification extent and readiness to start the process, positively influenced by temperature (30°C) and co-fermentation with yeast. Electronic nose analysis revealed that fermentations conducted only with pediococci generated higher peaks than mixed fermentations, with some isolates producing a more intense response in the e-nose; during the co-fermentation, the presence of yeast produces a uniform overall profile, in terms of intensities of the peaks expressed by the different sensors of e-nose. The leavening ability varied between isolates, with some reaching performance levels comparable to the yeast-only control. Electronic nose analysis provided rapid comparative profiling of volatile emissions, revealing structured differentiation among treatments, although requiring confirmation through sensory evaluation to validate the functional and organoleptic relevance of the observed differences.