A qualidade físico-química e microbiológica do músculo Longissimus dorsi em diferentes tempos de armazenamento

Abstract

This study aimed to evaluate the physicochemical and microbiological characteristics of beef sirloin (Longissimus dorsi) sold in the city of Dourados-MS, over different storage periods. The samples were purchased from a local butcher and stored in polystyrene trays covered with plastic film. The experimental design was completely randomized, with 20 trays distributed across five shelf-life periods, each with four replications. Analyses included pH, color (CIELAB system), water-holding capacity (WHC), cooking loss (CL), shear force (SF), proximate composition (dry matter, crude protein, ether extract, and ash), and microbiological evaluation (coliforms, Staphylococcus spp., Salmonella spp., molds and yeasts). Results showed significant pH variations (5.47 to 5.79) during storage, within the expected range for good-quality meat. Color parameters changed, with a decrease in redness (a* = 19.48 to 13.43) and an increase in yellowness (b* = 4.83 to 8.12), indicating myoglobin and lipid oxidation. WHC increased from 80.61% to 90.28%, enhancing juiciness, while CL ranged from 23.85% to 44.54%, indicating greater liquid loss during cooking. SF decreased from 9.29 kgf to 2.84 kgf, reflecting improved tenderness. Proximate composition showed 62.86% dry matter, 15.94% crude protein, 3.29% ash, and 33.98% ether extract. Microbiological results showed the absence of Salmonella spp., Escherichia coli, coagulase-positive Staphylococcus, and coliforms, with counts of mesophilic aerobes (<3.0 × 10¹ CFU/g) and molds and yeasts (<3.0 × 10 CFU/g) within legal limits, indicating good sanitary quality. It is concluded that storage time significantly influences the physical and sensory quality of the meat, improving tenderness and water retention capacity, although increasing cooking loss. The meat was considered microbiologically safe and nutritionally suitable for consumption during the evaluated periods.