This study aimed to apply different proteolytic enzymes (bromelain, papain, and flavourzyme) to develop texture-modified meats suitable for people with chewing or swallowing problems. The samples were categorised at level 6 (soft and bite-sized food) of the dysphagia diet, characterised in terms of physicochemical and textural parameters, and evaluated for their behaviour during gastrointestinal digestion simulating elderly alterations. In general, the enzyme-treated samples had lower moisture content, weight, and diameter of the piece of meat, and presented colour differences compared to the control samples. Textural analyses did not show significant differences in terms of hardness and cohesiveness for the texture-modified meats, while flavourzyme-treated samples presented less elasticity. Instrumental mastication assay showed the breakdown of samples' structure mainly during the first mastication cycles, with flavourzyme-treated samples presenting slightly higher consistency. The protein digestibility of the meats greatly increased after simulated gastrointestinal digestion, but a decrease in proteolysis for the control and papain-treated samples in the altered gastric model and an increase for flavourzyme-treated samples in the altered both gastric and intestinal model were shown compared to standard conditions. These results allow integrating knowledge to design foods that better meet the requirements of dysphagics or elderly people.

With growing consumer interest in meat quality, the need for accurate quality assessment becomes increasingly important. One crucial factor of Korean beef quality is the longissimus muscle area, which is closely associated with both quality and yield grade. Currently, the measurement is visually assessed, introducing subjectivity and placing a substantial burden on inspectors in terms of labor. To address these challenges, we have developed a compact image acquisition system designed to acquire accurate grading assessment images of beef carcasses. Several preprocessing steps after image acquisition were conducted, including radial distortion correction and color calibration. We have employed conventional image-processing techniques and four deep-learning models to segment the longissimus muscle area using the calibrated images. Among the segmentation models, DeepLab model based on ResNet50 achieved the highest accuracy. It demonstrated a Global Accuracy, Weighted IoU, and Mean BF Score of approximately 99.26%, 98.54%, and 95.70%, respectively. The results of our study are expected to contribute to the development of objective criteria for loin area assessment. By enabling precise and consistent determination of beef carcass quality, our research has the potential to reduce labor requirements for inspectors and provide a standardized approach to assessing loin area.

Meat from silvopastoral systems, due to its provision of numerous ecosystem services such as wildfire risk reduction in Mediterranean forests, can address societal growing demands for meat produced with lower environmental impacts. Differentiation of meat from these systems may contribute to their economic sustainability and hence to reverse their decline in the Mediterranean. This study investigated consumer preferences and willingness-to-pay (WTP) for beef and lamb meat from silvopastoral systems associated to the provision of wildfire prevention service and explored two alternative ways of labelling this service. Through a choice experiment survey considering type of pasture, length of grazing period, production distance and price, we gathered data from 1209 meat consumers in two Spanish cities. We considered forest grazing with a target purpose as a level in the type of pasture attribute and it was presented either as grazing to prevent wildfires or grazing to reduce biomass in two alternative versions of the valuation survey. The random parameter logit model revealed the highest preferences and WTP towards nearby production distances, followed by targeted grazing and forest grazing, while the length of grazing period was less relevant. No significant differences in consumers WTP were found between conveying targeted grazing either as fire prevention or biomass reduction. Our findings also suggest that consumers' preferences varied with location, attitudes towards local food and environmental role of grazing and consumption habits. Knowledge gathered in our work contributes to understand consumers perceptions on the beneficial environmental impacts of meat production.

In skeletal muscles, mitochondria have been shown to decrease the oxygen affinity of myoglobin. In this study, we investigated whether the mitochondrial function of decreasing myoglobin affinity for oxygen persists and operates at the final pH of postmortem bovine skeletal muscle. The oxygen affinity and myoglobin consumption in the presence of mitochondria obtained from fresh and wet-aged beef were evaluated and compared at pH5.1, 5.6, and 5.7. The results showed that mitochondria obtained from fresh beef preserved myoglobin oxygen consumption and affinity interference, whereas those obtained from wet-aged beef did not. Oxygen consumption and affinity interference were mostly absent at pH5.1 and were higher at pH5.7 than those at pH5.6. Our findings suggest that mitochondria contribute both to an increase in the oxygen affinity of myoglobin in aged meat and a decrease in the oxygen affinity of myoglobin in high-pH meat, such as dark-cutting beef.

Reduction in muscle glycogen triggered by adverse antemortem handling events alters postmortem energy metabolism and results in a high ultimate pH and dark, firm and dry beef, often referred to as 'dark-cutting'. However, the relationship between atypical dark (AT) beef, postmortem energy metabolism and underlying tissue characteristics remains somewhat unclear. Cattle harvested in the US and Canada representing normal (pH<5.6), AT dark (pH5.6-5.8) and dark cutting (DC; pH>5.8) beef were analyzed for tissue characteristics related to energy metabolism. Results show AT dark beef is more oxidative but similar to normal beef in glycolytic potential and nucleotide abundance. Mitochondria DNA content (P<0.05, Canada; P<0.005, US) and oxidative enzymes for DC and AT dark beef were greater (P<0.01; Canada and US) compared to normal beef. Myoglobin tracked (P<0.01) with color classification. These findings show both DC and AT beef are inherently more oxidative and raise the possibility that more oxidative muscle may be more prone to develop dark beef.

This review has been developed as part of the mEATquality project with the main objective to examine the types of extensification practices used in European pig husbandry and their effect on intrinsic meat quality. Literature search has resulted in 679 references in total, from which 53 showed a strict compliance with the goals of this review: 1) the use of local European breeds and their crossbreds (22 papers); 2) addition of forage to diet (9 papers); 3) increased space allowance (3 papers); 4) enrichment of environment (19 papers). The evaluation of selected extensification factors showed that not all of them have a clear impact on meat quality, and are often confounded. The most clear differences were observed when comparing autochthonous with commercial breeds, and systems with access to pastures or woodlands vs. indoor housing. Despite many studies focusing on the extensification of husbandry practices, some of the factors cannot be confirmed to have a direct effect on pork intrinsic quality.

This study evaluated collagen solubility and gene expression of biomarkers for intramuscular collagen (IMCT) deposition and remodeling in the Longissimus muscle of bulls and steers through the finishing phase. Thirty-six Nellore calves were used (18 bulls and 18 steers), and six of each sexual condition were randomly assigned to be harvested at 0, 100, or 200days on feed (DOF) to evaluate collagen characteristics in different time points throughout the finishing phase. Bulls showed a greater collagen solubility than steers (P=0.03). The gene expression of fibrogenic markers (TGFβ1, COL1A1, and COL3A1) and IMCT remodeling mediators (MMPII, TIMPII, and LOX) were not affected by sexual condition or DOF (P>0.05). Our data indicate that young Nellore bulls have a higher percentage of soluble intramuscular collagen, possibly due to higher collagen remodeling associated with a faster growth rate and muscle hypertrophy. Moreover, castration and DOF did not modify mRNA levels of fibrogenic and collagen remodeling markers.

The typical dry-cured ham flavor is rich in umami and brothy perceptions, for which short peptides may contribute. Particularly, γ-glutamyl peptides could be the responsible of these previously reported attributes, as they exert a synergistic interaction with other basic tastes and modify the intensity of salty, sweet, and umami tastes. The content of peptides has been reported to evolve along the processing, but no kokumi γ-glutamyl peptides have been identified in Spanish dry-cured hams yet. In this research, nine γ-glutamyl dipeptides (γ-EA, γ-EC, γ-EE, γ-EF, γ-EL, γ-EM, γ-EV, γ-EW, and γ-EY) and two γ-glutamyl tripeptides (GSH and γ-EVG) have been quantitated at 6, 12, 18 and 24months of traditional processing of Spanish dry-cured ham by performing a Q Exactive Orbitrap-based tandem mass spectrometry. The results show an increase of γ-EA, γ-EE, γ-EF, γ-EL, γ-EM and γ-EVG, obtaining maximums at 24months of curing ranging from 0.14 (γ-EVG) to 18.86 (γ-EL) μg/g dry-cured ham. Otherwise, γ-EV, γ-EW and γ-EY accumulated until the 18th month of storage to 15.10, 0.54 and 3.17μg/g dry-cured ham, respectively; whereas γ-EC and GSH amounts decreased starting from 0.0676 and 4.41μg/g dry-cured ham, respectively at earlier stages. The concentration dynamics of these compounds may be linked with proteolytic and oxidative reactions during processing. In addition, due to their synergistic effect on kokumi activity, this could constitute insights of the brothy perceptions of dry-cured ham, and these peptides probably contribute to the sensory differences existing in long processed Spanish dry-cured hams.

The color of fresh pork is a crucial quality attribute that significantly influences consumer perception and purchase decisions. This review first explores consumer expectations and discrimination regarding pork color, as well as an overview of the underlying factors that, from farm-to-fork, contribute to its variation. Understanding the husbandry factors, peri- and post-mortem factors and consumer preferences is essential for the pork industry to meet market demands effectively. This review then delves into current knowledge of pork myoglobin chemistry, its modifications and pork discoloration. Pork myoglobin, which has certain peculiarities comparted to other meat species, plays a weak role in determining pork color, and a thorough understanding of the biochemical changes it undergoes is crucial to understand and improve color stability. Furthermore, the growing role of proteomics as a high-throughput approach and its application as a powerful research tool in meat research, mainly to decipher the biochemical mechanisms involved in pork color determination and identify protein biomarkers, are highlighted. Based on an integrative muscle biology approach, the available proteomics studies on pork color have enabled us to provide the first repertoire of pork color biomarkers, to shortlist and propose a list of proteins for evaluation, and to provide valuable insights into the interconnected biochemical processes implicated in pork color determination. By highlighting the contributions of proteomics in elucidating the biochemical mechanisms underlying pork color determination, the knowledge gained hold significant potential for the pork industry to effectively meet market demands, enhance product quality, and ensure consistent and appealing pork color.

Chestnut tannins (CNT), as a source of hydrolyzable tannins, positively affect the antioxidant status of livestock. In the current study, 90 male Hu lambs were used to investigate the effect of dietary CNT intake on growth performance, nutrient digestibility, meat quality and oxidative stability, rumen microbial, and the transcriptomes of muscle and liver. A completely randomized design with three CNT intake levels (0, 0.3%, and 0.6%) was used. Rumen microbial and nutrient digestibility were not significantly altered by CNT intake. Diets with 0.3% CNT intake significantly reduced the shear force, yellowness at 24h, and C20:2 polyunsaturated fatty acids of lamb meat and malondialdehyde in serum and longissimus thoracis (LT) muscle. Meanwhile, the 0.3% CNT diet significantly increased average daily gain during the 1-21days and 64-90days, dry matter intake during the 1-21days, the slaughter weight, and liver index of lambs. The 0.3% CNT diet significantly increased C26:0 saturated fatty acids, total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase in LT muscle. The meat shelf life of 0.3% CNT and 0.6% CNT groups was prolonged by 8.7h and 5.4h, respectively. Transcriptomic analysis revealed that CNT supplementation can induce the expression of antioxidant enzyme gene (CAT, SOD1), and the differentially expressed genes were mainly involved in antioxidant activity, transferase activity, and adenosine triphosphate binding. These results suggest that 0.3% CNT intake can relieve the oxidative stress of lambs, and improve the stability of meat color and meat tenderness, due to the enhanced antioxidative capacity.