Propolis modulates microbial communities and enhances safety in Chorizo de León: A metataxonomic study

The search for natural, sustainable alternatives to synthetic preservatives is a growing priority in the meat industry. This study evaluated the potential of an ethanolic extract of Spanish propolis (EEP) as a natural bio-preservative in Chorizo de León, focusing on its effects on physicochemical stability, microbial safety, and community dynamics during ripening. A chemically characterized EEP rich in phenolic acids and flavonoids was incorporated into traditional sausage formulations and compared with control batches during a 30-day maturation period. Physicochemical parameters, including pH, water activity, curing salts, and sensory attributes, along with microbial counts such as Enterobacteriaceae, lactic acid bacteria, Listeria monocytogenes, and Clostridium sporogenes, as well as microbial diversity, were assessed using classical microbiology techniques and 16S rRNA metataxonomic sequencing. EEP addition did not alter key technological parameters or sensory quality, confirming that propolis did not interfere with fermentation or dehydration processes. However, propolis-enriched batches showed accelerated reductions in Enterobacteriaceae and C. sporogenes, along with increased microbial richness and evenness. Metataxonomic analysis revealed that propolis promoted the dominance of beneficial lactic acid bacteria (Latilactobacillus, Leuconostoc, Weissella) and reduced spoilage-associated genera such as Pseudomonas and Psychrobacter. Principal coordinate analysis confirmed that propolis exerted a stronger effect on microbial community structure than ripening time or inoculation. Overall, Spanish propolis proved to be a viable, sustainable bio-preservative for fermented meat products, enhancing microbial safety and ecological stability while maintaining product quality. These findings support its potential as a clean-label alternative to synthetic additives in traditional cured meats.