Assessment of the Impact of Fruit Vinegars on the Tenderness and Quality Attributes of Spent Hen Meat

This study aimed to evaluate the impact of marinades formulated with fruit vinegars (grapefruit, jujube, pineapple, strawberry) on the physicochemical, structural (Texture Profile Analysis-TPA, Warner-Bratzler shear force-WBSF, shear energy-WBSE, Scanning Electron Microscope-SEM), microbiological (total mesophilic aerobic bacteria, total psychrotrophic aerobic bacteria, coliform bacteria, <i>Escherichia coli</i>, yeast, and mold), and sensory characteristics (odor, color, flavor, texture, overall acceptance) of sample from 83-week-old spent laying hens, which are typically known for their tough texture. The samples were manually mixed to evenly distribute the solid components within the marinades, then refrigerated at 4°C for 24 h. Following marination, they were cooked in a convection oven at 160°C for 30 min. The addition of vinegar contributed to lower pH levels and reduced cooking loss in the meat. The highest moisture content and water-holding capacity were observed in the Cp group. Marination with vinegar caused a significant reduction in <i>L*</i> values, while it resulted in an increase in <i>a*</i> values. SEM images revealed that marination with vinegar led to extensive degradation of connective tissues. Meat marinated with pineapple and strawberry vinegar showed significantly lower hardness, WBSF, and WBSE (<i>p</i> < 0.05). These results were further supported by sensory analysis, as texture scores aligned with the TPA and SEM findings. Marination with vinegars caused a significant reduction in microbial counts. The findings indicate that among the vinegars studied, pineapple and strawberry vinegar emerge as effective natural tenderizing agents, enhancing the textural properties of tough meats while potentially improving other quality attributes.