Enhancing “Ewiss” cheese production using autochthonous lactic acid bacteria and Propioniciclava flava as an alternative to commercial propionic acid bacteria

This study explored enhancing Ewiss cheese's regional identity by using native starter cultures to develop a "regional cultured Ewiss cheese" (RCEC). Lactic acid bacteria (LAB) were previously isolated from local cheeses and selected from the University of Palermo culture collection (Streptococcus thermophilus strains RC-UNIPASAAFM00189, RC-UNIPASAAFM00233, RC-UNIPASAAFM00239, and RC-UNIPASAAFM00249), while Propioniciclava flava (RC-UNIPASAAFM01343) was isolated during this study. LAB were added as defined whey starters post-pasteurization; Pc. flava was introduced as an adjunct culture at pH 6.4. Microbial dynamics were monitored throughout cheese ripening. Thermophilic LAB dominated early stages; propionic acid bacteria increased after 9 months. Metataxonomics analysis revealed Streptococcus and Lactobacillus as dominant. Thirtyone volatile organic compounds were identified, with propionic acid most abundant. A control cheese using commercial cultures was produced for sensory comparison. Sensory analysis revealed that RCEC made with autochthonous cultures scored higher than the control in terms of overall acceptability. These results support Sicilian dairy diversification and valorisation.