Microbial dynamics and quality traits of dry- and wet-aged Bruna dels Pirineus beef

Beef consumption in Europe has steadily declined due to shifting consumer preferences, health concerns, and growing awareness of environmental and ethical issues. In parallel, interest is increasing in native breeds that support biodiversity, sustainable farming, and differentiated products. The Bruna dels Pirineus, an endangered breed native to the Catalan Pyrenees, is a valuable genetic and cultural resource, yet its potential for premium beef production remains underexplored. This study evaluated the effects of dry- and wet-aging for 4 and 8 weeks on the technological, sensory, and microbial characteristics of sirloins from 11 Bruna dels Pirineus cattle. Analyses included technological traits, sensory evaluation, microbial enumeration pathogen screening via PCR, and 16S rRNA gene sequencing. Aging significantly influenced color, tenderness, and texture, with very tender meat achieved after 4 weeks. Beef odor and flavor remained stable, while aged notes slightly increased over time. Microbial enumeration revealed higher viable counts in dry-aged meat, increased lactic acid bacteria (LAB) in wet-aged samples, and contrasting trends for Pseudomonas spp. and yeasts/molds. No foodborne pathogens were detected. Metataxonomic analysis revealed distinct communities, with wet-aged meat dominated by LAB (Lactobacillus, Leuconostoc, Carnobacterium) and dry-aged meat by Pseudomonas spp. and Brochothrix thermosphacta. These findings demonstrate that both aging methods enhance meat quality through controlled physicochemical and microbial transformations while maintaining safety. This work supports the valorization of Bruna dels Pirineus beef and highlights the need for further studies linking microbial dynamics to sensory and chemical traits.