Quality Assessment of Commercial Dry-Aged Beef Produced in Poland

The aim of the study was to evaluate the physicochemical, microbiological, and biochemical quality of commercially available dry-aged beef produced in Poland, with particular emphasis on differences between the crust and the interior of steaks. Fourteen samples (11 rib-eye and 3 sirloin) from different producers were analysed. The colour parameters, pH, water activity, thiobarbituric acid reactive substances, water-holding capacity, basic chemical composition, texture, microbial counts, free amino acids, biogenic amines profiles, and consumer sensory quality were determined. Microbiological analyses covered total plate count, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp., Brochothrix thermosphacta, yeasts and Moulds, as well as the presence of Salmonella spp. and Listeria monocytogenes. Fungal species isolated from selected crust samples were identified using ITS rDNA sequencing. Significant variability among products was observed in colour (L*: 31.1-45.0), pH (5.3-6.7), and water activity (0.92-0.99). Compared with the interior, the crust exhibited higher lipid oxidation (TBARS up to 2.31 mg MDA/kg), higher microbial loads, and greater accumulation of biogenic amines, including tyramine, cadaverine, and putrescine. Rib-eye 6, Rib-eye 7, Rib-eye 8, Rib-eye 10, and Rib-eye 11 showed the highest sensory acceptance. On the crust of selected highly rated steaks filamentous fungi such as Mucor flavus and Thamnidium elegans were identified, which suggests environmental colonisation and potential technological relevance.