RESUMO
This study investigated cadaverine as a spoilage indicator in commercial beef products stored under conditions favourable for the growth of lactic acid bacteria. Samples included vacuum-skin-packed entrecotes (EB) aged up to 42 days and modified-atmosphere-packed (70% O2 + 30% CO2) minced beef (MB) stored at 5 °C. Two MB product lines were analysed: one stored aerobically two days post-slaughter before mincing and another stored for 14 days in vacuum packaging prior to mincing. Sensory assessment/evaluation and microbial analysis were performed throughout the shelf life of the products and compared to cadaverine levels measured using LC-MS/MS. Cadaverine concentrations in EB reached approximately 40,000 µg/kg on the "best before" date, while remaining below 50 µg/kg in both MB products on the corresponding date. While cadaverine concentrations in EB displayed a consistent increase, suggesting its potential as a spoilage indicator post-ageing, the low concentrations in MB, did not correlate with sensory assessments, revealing its limitations as a universal spoilage marker. In conclusion, it is necessary to conduct product-specific studies to evaluate the applicability of cadaverine as a spoilage indicator for beef products.
RESUMO
The importance of carnobacteria as spoilage microorganisms or potential protective cultures in food is not resolved, and little is known about their metabolism during growth in specific products. This study used chromatographic techniques including GC-MS and HPLC to evaluate the spoilage metabolism of Carnobacterium divergens, Carnobacterium maltaromaticum, and Carnobacterium mobile. Metabolic activity was studied in cooked and peeled modified atmosphere packed (MAP) shrimp at 5 degrees C as carnobacteria has been anticipated to contribute to spoilage of shrimp products. C. divergens and C. maltaromaticum caused sensory spoilage of shrimps and generated ammonia, tyramine, and various alcohols, aldehydes, and ketones. The effects of Carnobacterium species on the growth and metabolism of Brochothrix thermosphacta were also evaluated, but metabiosis between the two groups of bacteria was not observed. C. mobile and a specific cluster of C. maltaromaticum isolates (cluster L) did not cause sensory spoilage of shrimp.