Non-invasive meat quality assessment: Exploring the potential of ocular infrared thermography to predict ultimate pH in Nellore beef cattle.

This study investigated the use of infrared thermography (IRT) to identify the dark, firm, and dry (DFD) phenomenon in Brazilian beef, which is a significant concern for the industry because of its inferior quality and reduced shelf life. This study examined 113 Nellore bulls and analyzed their minimum and maximum ocular temperatures using IRT. The results highlight the efficacy of thermal images (IRTmax) as a significant predictor, with R2 values ranging from 0.84 to 0.88 for calibration models. The inclusion of parameters such as glucose and lactate further enhanced prediction accuracy. The models also revealed that the combination of features, such as lightness (L*), redness (a*), and yellowness (b*), contributed to the precise prediction of pHu, with an R2 of 0.88. In model validation, RMSEP ranged from 0.104 to 0.158, indicating good generalization capability. The RPD, ranging from 1.7 to 2.6, suggests satisfactory quantitative prediction. The statistical significance of all models, evidenced by P-values <0.001, strengthens the reliability of the results. In conclusion, the models support the use of IRT as a tool for identifying pHu alterations in carcasses. When combined with blood parameters, they may exhibit even greater efficiency in predicting pHu in Nelore cattle carcasses, highlighting the potential applicability of these methods in the beef industry.

Sensory quality of beef with different ultimate pH values - A Brazilian perspective.

This study evaluated Brazilian consumer perceptions of beef with different pH values at 48 h post-mortem (pHu) through sensory analysis. A total of 138 consumers evaluated raw and grilled steaks. The steaks were divided according to their pHu (normal pH < 5.8, atypical darkness, firmness, and dryness [DFD] > 5.8 pH < 6, and typical DFD pH ≥ 6). There was no difference in the visual evaluation of raw steaks or purchase intention. Evaluation of the grilled steaks showed that consumers preferred typical DFD steaks in terms of tenderness, and there was a tendency for the same behavior in terms of juiciness. No differences were observed in other evaluated parameters. Cluster analysis identified three consumer segments for visual evaluation, indicating a preference for steaks with higher pHu in terms of freshness. Additionally, four segments were identified for evaluation, with some groups expressing a preference for higher pHu meat in terms of freshness appearance, tenderness liking, and overall liking. The developed regression models for overall liking and purchase intention exhibited favorable adjustment indices, with r2 values of 0.86 and 0.57, respectively, for raw steaks and 0.90 for grilled steaks for in overall liking. Regression models indicated a strong influence of color and freshness appearance, in addition to tenderness liking and juiciness liking, on the overall liking scores of consumers. These results indicate that Brazilian consumers do not dislike dark cutting and, despite differentiating their greater tenderness, do not show a preference between the different pHu values.

Gender effects on pork quality and calpain-1 and calpastatin gene expression in male pig muscle.

Studies that investigate the expression of genes related to the tenderness of meat from entire and immunocastrated male pigs have not yet been performed. The objective of this study was to investigate the association between gender (entire male and immunocastrated) and the meat quality of pigs, as well as to quantify the expression of calpain-1 and the calpastatin gene. Regarding carcass measurements and meat quality, boars presented lower values of muscle depth (P = 0.028), subcutaneous fat thickness (P = 0.046), L* value (P = 0.004) and cook loss (P = 0.008) than the immunocastrated pigs. The boars presented greater calpain-1 gene expression (P = 0.006) and lower calpastatin gene expression (P = 0.003) than immunocastrated pigs. This study shows that combined with other factors the gene expression can contribute to a tender meat from boars due to their higher calpain-1 expression and lower calpastatin expression than those of immunocastrated male pigs.