Muscle pH Research Articles

Histidine improves flesh quality: An assessment of grass carp (Ctenopharyngodon idella) muscle in terms of texture, nutritional value and flavor.

The texture, nutritional value, and flavor quality of muscle significantly contribute to the flesh quality. To investigate the beneficial impacts of histidine on the flesh quality of grass carp (Ctenopharyngodon idella), a 63-day feeding trial was conducted using six diets containing histidine at concentrations of 1.08 (control diet), 2.91, 5.87, 8.83, 11.78, and 14.79g/kg. The findings indicated that histidine mitigated the rapid decline in pH, potentially correlated with elevated carnosine and expression of H+ transporters. Notably, our study is the first to suggest that histidine supplementation may enhance fish flesh hardness by promoting collagen synthesis and inhibiting collagen degradation. Furthermore, histidine supplementation enhanced the nutritional and flavor quality of flesh by altering the fatty acid and free amino acid profiles. Based on pH24h (muscle pH at 24h post-slaughter) and shear force, the dietary histidine requirements for adult grass carp were 8.09 and 8.44g/kg, respectively.

Is the time to task failure during severe intensity exercise associated with muscle, blood, and respiratory changes?

Purpose: The study aimed to verify the physiological and metabolic parameters associated with the time to task failure (TTF) during cycling exercise performed within the severe-intensity domain. Methods: Forty-five healthy and physically active males participated in two independent experiments. In experiment 1, after a graded exercise test, participants underwent constant work rate cycling efforts (CWR) at 115% of peak power output to assess neuromuscular function (Potentiated twitch) pre- and post-exercise. Experiment 2 was similarl to experiment 1, but with physiological (respiratory parameters, energetic pathway contribution) and metabolic parameters in the blood (gasometry and blood lactate responses) and vastus lateralis muscle tissue (target metabolomic analysis, glycogen content, muscle pH and buffering capacity in vitro) measured instead of neuromuscular function. Results: Experiment 1 evidenced a significant decrease in muscle force with instauration of peripheral fatigability indices and no change in central fatigue indices. Severe-intensity domain exercise in Experiment 2 was accompanied by changes in physiological and metabolic parameters and in blood and muscle parameters. However, the TTF was associated with oxidative contribution (r=0.811, p<0.001), as well as anaerobic capacity (r=0.554, p=0.027), muscle buffering capacity (r=0.792, p=0.035), phosphagen energy contribution (r=0.583, p=0.017), and carnitine changes (r=0.855, p=0.016), but no correlated with electromyographic response, blood acid-base balance, and muscular glycogen content and pH. Conclusion: TTF during CWR exercise within the severe-intensity domain is likely explained by a combination of interacting mechanisms, with oxidative and phosphagen contributions, and muscle buffering capacity suggested as the main peripherals limiting factors to exercise within this exercise intensity domain.

Intramuscular pH monitoring before and during exercise in individuals with intermittent claudication compared to healthy controls: A feasibility study.

In this feasibility study, firstly, we aimed to assess whether intramuscular pH (IMpH) could be measured with a glass-tipped electrode. Secondly, we aimed to explore whether we could monitor changes in skeletal muscle pH before and throughout static (isometric) and after dynamic (treadmill) exercise, comparing individuals with intermittent claudication (IC) to a group of healthy controls. Forty participants with IC (mean age ± SD) 68 ± 8) and 40 healthy volunteers (63 ± 10) were recruited. Participants in the IC group had an ankle brachial pressure index of <0.7 (mean: 0.62 ± 0.13). The first 20 participants in each group underwent isometric ankle dorsiflexion for 120 s at 30% of maximum voluntary contraction and the remainder underwent treadmill exercise (3.6 km/h, 5° incline) to maximal walking distance. A sterilised reusable 1.5 mm shatterproof, heat strengthened glass tipped pH probe inserted using a peripheral venous cannula and in combination with a pH meter was used to measure IMpH of the tibialis anterior muscle prior to, during and continuously for 1 h after exercise. Resting IMpH was similar between the groups (median 6.8 (interquartile range (IQR) 6.7-6.9)) for IC individuals and 6.7 (6.6 to 6.8) for controls). Following isometric exercise, the magnitude of the decrease in IMpH was greatest in the IC group (median ΔpH max. in patients -0.2 (IQR: -0.2 to -0.1) versus -0.1 (IQR: -0.2 to -0.1) in the control group (p = 0.002). After treadmill exercise, the magnitude of the decrease in IMpH (ΔpH max) was greatest in individuals with IC (median ΔpH max. in patients -0.3 (IQR: -0.3 to -0.3) versus 0 (IQR: -0.2 to 0) in the control group, p = 0.04. IMpH monitoring with a flexible glass probe inserted into the tibialis anterior muscle is viable and changes in IMpH during static and dynamic exercises are detected.

Impact of Sodium Bicarbonate-Enriched Diet on Muscle pH and Quality of Rainbow Trout (Oncorhynchus mykiss) During Cold Storage

The effect of sodium bicarbonate (SB) supplementation to fish feed on the quality characteristics of rainbow trout (Oncorhyncus mykiss) under post-harvest cold storage conditions was investigated in this study. Rainbow trout fed with 0, 1M, 2M and 3M SB supplemented diets for 21 days before harvesting were stored at 4°C. The highest post-harvest pH level was observed in the group fed with 2M and 3M SB. TVB-N value was found between 14.88-15.68 mg/100g in fish fed with 1M, 2M and 3M SB supplemented diets, while it was determined as 20.14 mg/100g for the control group. At the beginning of storage, similar TBARs values were observed in all groups; however the increase in TBARs in the groups fed with SB supplemented feeds was slower than in the control. Sensory scores of trout fed with SB supplemented diets at the beginning of storage were higher than those of the control group. However, no difference was determined between the groups regarding shelf life (13 days). The best texture scores were observed in the 3M group throughout the storage period. Therefore, it can be concluded that SB addition to pre-harvest rainbow trout feeds can be used as a feed supplements to improve fish flesh quality.

Exploring the Nexus of Feeding and Processing: Implications for Meat Quality and Sensory Perception.

The intrinsic quality of meat is directly related to muscle and fat tissues. Factors such as the rate and extent of anaerobic glycolysis affect muscle pH, influencing the meat's color, water holding, and texture. Postmortem anomalies can result in deviations from this intrinsic quality. The animals' diet plays a crucial role in meat quality. Specific nutrients, such as proteins, vitamins, and minerals, affect meat's texture, flavor, and juiciness. Feeds rich in omega-3 fatty acids can improve the sensorial quality of meat. Meat processing and methods such as aging, marinating, and cooking affect the texture, flavor, and juiciness, which can be evaluated by specific equipment or trained or untrained consumers. This comprehensive review investigates the relationship between animal feeding practices and meat processing techniques and their combined impact on meat quality and sensory perception. By synthesizing recent research, we explore how various feeding protocols (including diet composition and feed additives) and processing methods shape meat products' nutritional value, texture, flavor profile, and overall consumer appeal. Understanding this nexus is crucial for optimizing meat quality while ensuring sustainability and safety in the food supply chain.

Glycogen Supplementation in Vitro Promotes pH Decline in Dark-Cutting Beef by Reverting Muscle's Metabolome toward a Normal Postmortem Muscle State.

Dysregulated muscle glycogen metabolism preslaughter contributes to aberrant postmortem muscle pH (>5.8) in dark-cutting beef phenotypes. However, the underlying mechanisms have remained elusive. Herein, we examine the glycogen dependent regulation of postmortem muscle pH decline and darkening in beef. We show that supplementation of glycogen in vitro restores postmortem pH decline in dark-cutting beef by reverting the metabolome toward a typical postmortem muscle state characterized by increased activities of enzymes glycogen phosphorylase and lactate dehydrogenase (p < 0.05) coupled with a pronounced abundance of glycolytic metabolites and reduced abundance of tricarboxylic acid cycle and amino acid metabolites. Furthermore, concurrent inhibition of mitochondrial respiration at complexes I, IV, and V with glycogen supplementation stimulates greater pH decline. Together, our findings show that supplementing glycogen at low concentrations (10 mM) can reprogram the dark-cutting beef muscle's metabolome toward typical postmortem state and promote muscle acidification. Thus, enhancing glycogen levels could represent a promising strategy for mitigating dark-cutting beef phenotypes and improving meat quality.

Effects of preslaughter handling approach and aging on carcass and meat quality attributes in goats

This study aimed to assess the impact of preslaughter handling method and aging on carcass and meat quality traits in goats. Twenty-seven male goats of Ardi breed were assigned into three treatment groups viz., the control (C), ear pulling (EP), and hind-leg pulling (HP). The carcasses were stored for post-mortem aging periods of 1, 7, and 14 days. On day 0 and the respective aging days, samples of the Longissimus thoracic et lumborum (LTL) muscles were collected and examined for various meat quality parameters. The preslaughter handling of goats significantly increase the total bacterial count, total Enterobacteriaceae count, and total Clostridium count. It also had a significant effect on the pH of LTL muscle during aging. A significantly lower values for pH were recorded in the treatment groups (EP and HP) as compared to the pH of the C group on day 1 of aging. Notably, both treatment groups were found to increase the shear force, hardness, and chewiness of the meat, ultimately compromising its quality. The proper treatment of meat animals, especially goats, is crucial for enhancing carcass and meat quality. Careful preslaughter handling practices by avoiding ear and hind-leg pulling can minimize negative impacts on the final product. Therefore, the significance of conducting this study lies in its potential to enhance animal welfare, improve meat quality, boost economic benefits for producers, and foster consumer confidence in meat products.

Comparative study on slaughter performance, meat quality, and rumen microbiota of Hainan Dong goat and its hybrid with Nubian goat.

The Hainan Dong goat (DG) is a local meat breed widely raised in Hainan, China because of its good adaptability to local hot and humid weather. However, the growth rate of these DG is much slower than that of commercialised breeds improved in European countries, resulting in poor carcase characteristics, including smaller slaughter weight and carcase weight, which have become increasingly prominent. In recent decades, Nubian goats have been continuously imported into China to improve the production performance of local breeds. In this study, the effects of breed on growth performance, carcase and meat quality, and ruminal microbiota were analysed in 40 goats, including 20 DGs and 20 hybrid F3 offspring generated by crossing the DG and Nubian hybrids (NH). All the goats were averagely aged 90 days and weighed at 11 ± 1.34 kg. They were assigned to two treatments, with three replicates per treatment. The two groups were fed the same diet for 90 days before slaughter. The results showed that the average daily gain, F/G ratio, slaughter weight, and carcase weight of the NH group were higher than those of the DG group (p < 0.05). However, tube circumference, meat-to-bone ratio, and eye muscle pH were lower in the NH group than in the DG group (p < 0.05). The NH group showed a smaller fibre crosssectional area and fibre diameter, but a larger fibre density than the DG group (p < 0.05). Bacteroidetes and Firmicutes were the most dominant phyla in the two groups; however, the two breeds had different ruminal microbial communities. In the present study, the differences in growth performance between two groups of goats under the same feeding environment and feed conditions were compared. The correlation between feed sources and rumen flora has been demonstrated, and the results of this study show that the same diet has similar effects on rumen microorganisms, which in turn have related effects on growth and production performance. In summary, hybrids can improve the growth and slaughter performance of local breeds, which may be related to changes in the rumen microorganisms. This study revealed that crossbreeding of Nubian goats with Dong goats has the potential to be used in a wide range of applications owing to its effectiveness in increasing production efficiency.

Influence of lipid and metabolite profiles of mitochondrial fraction on pH and color stability of longissimus lumborum muscle with different ultimate beef pH

This study aimed to explore the differences in the lipidome and mitochondrial fraction metabolome of Nellore cattle meat in different ranges of ultimate pH (pHu) normal (≤5.79), intermediate (5.80 to 6.19) and high (≥ 6.20) after 3- and 21-d postmortem. Instrumental color, myoglobin redox state, oxygen consumption, and metmyoglobin-reducing activity were measured during storage. A total of 472 lipids and 22 mitochondrial fraction metabolites were identified. Beef with high pHu showed positive regulation of ceramides involved in apoptosis and negative regulation of lipid classes related to membrane permeability and stability. In addition, lower carnitine content was noted in high-pHu beef than in normal-pHu beef. Acylcarnitines, phosphatidylinositol, and IMP showed upregulation in beef with intermediate pHu, indicating changes mainly related to energy, purine and pyruvate metabolism. Aging time impacted on the lipid content and metabolites involved in different metabolic pathways. These results provided new insights into beef's mitochondrial fraction lipid and metabolic profile with different pHu. In addition, beef with intermediate pHu differs from beef with high pHu due to changes in energy metabolism.

Influence of age at slaughter and sex on carcass characteristics, meat quality, fatty acids, and ribonucleotides in white-tailed yellow native chickens.

This study investigated the effects of age and sex on carcass and meat characteristics of one of Thailand's major indigenous chicken breeds, the white-tailed yellow native chicken (NC). A total of 120 one-day-old NC (60 males and 60 females) were raised, and harvested at either 16, 20 or 24 weeks. The results showed that body, carcass, breast and fillet weights did not differ (P > 0.05) between 16- and 20-week-old NC, but were lower (P < 0.05) than those of 24-week-old NC. Male NC had higher (P < 0.05) body, carcass, wing, back and thigh weights than female NC. Neither sex nor age affected muscle pH, sarcomere length, redness and yellowness, guanosine monophosphate, and hypoxanthine. The interaction between age and sex was significant (P < 0.05) for %dressing, %leg, L*, C14:1, C18:1n9 and C20:4n6. Shear force was lower in 16-week-old NC (P < 0.05). The 24-week-old NC had lower (P < 0.05) C13:0, C16:0, C18:0, C18:2n6t, C20:4n6, C22:6n-3, intramuscular fat and inosine 5'-monophosphate levels and higher (P < 0.05) C18:2n6c, C18:3n-3 and C20:3n-6 levels than the 16- and 20-week-old NC. Male NC had higher (P < 0.05) C13:0-, C14:0-, C18:2n6t-, C20:3n-6- and lower inosine levels than female NC. In conclusion, these data highlight age- and sex-specific differences in carcass and meat quality of NC and provide relevant information to support consumer-oriented decisions on the production, processing and nutritional value of NC.

Comparative Analyses of Muscle Quality in Hooked, Trawl-Net, and Radar-Net Hairtail (Trichiurus haumela) during Thermal Processing.

To investigate and compare the changes in muscle quality of hooked, trawl-net, and radar-net hairtail (Trichiurus haumela, HH, TH, and RH) during thermal processing, the physicochemical properties of three kinds of hairtail were determined under heating at 30, 50, 70 and 90 °C for 10 min. Additionally, the muscle tissues were observed via Oil Red O (ORO) staining, Masson staining, and scanning electron microscopy (SEM). The results showed that with increased heating temperature, pH, L*, b*, chewiness, and gumminess in hairtail muscle increased, while a* and shearing force decreased. The springiness, relative contents of hydrophobic and disulfide bonds, myosin surface hydrophobicity, and TCA-soluble peptide content increased first and then decreased. However, the relative contents of ionic and hydrogen bonds showed an opposite trend. Histological observations revealed that heating disrupted hairtail muscle tissue, manifested by the blurriness and disorder of myofibrils and breakage of myofibrillar bundle membranes. The RH muscle exhibited the highest chewiness, gumminess, and chemical force levels, accompanied by the lowest content of TCA-soluble peptide. Furthermore, the RH muscle presented the greatest fat droplet content, diffusivity, and integrity of collagen and myofibers. Correlation analysis revealed a close correlation between muscle quality and protein function in HH, TH, and RH. This study provides a theoretical basis for the difference in muscle quality in three different types of hairtail.

PSVII-21 Impact of low voltage electrical stimulation applied to longissimus thoracis et lumborum and semitendinosus on meat quality and palatability

Abstract Low voltage electrical stimulation (LVES, 20-120V) is safer and more cost-effective than high voltage electrical stimulation (HVES). Despite some studies showing positive effects of LVES on meat quality, no studies have evaluated the effects of LVES on meat flavor profile. The objective of this study was to examine the effects of LVES applied directly to the longissimus thoracis et lumborum (LTL) and semitendinosus (ST) muscles on meat quality and flavor profile. Steers [n = 32; 689.2 ± 29.66 kg body weight (BW)] were used. After carcass splitting and randomizing by carcass side, the LTL and ST of one carcass side were stimulated individually with 45 VRMS at 49.83 ± 2.32 min post-mortem using a commercial stimulator. The other carcass side remained unstimulated. The LTL and ST pH were measured at 45 min, 3 h, 3 d and 6 d. At 3 d post-mortem, LT objective color (Minolta L*, a*, b*, hue, chroma) was measured and one steak from LT and ST were collected for cooking losses and shear force analyses. The remaining muscle was weighed, vacuum-packaged, aged until 6 d post-mortem and, subsequently, unpackaged and re-weighed to calculate purge losses. One steak from each muscle was placed in a retail display and objective color at 0 and 4 d (6 and 10 d post-mortem) and drip losses were assessed. Cooking losses and shear force of 6- and 12-d aged steaks from each muscle were measured. Trained panelists evaluated sensory attributes of frozen-thawed 6-d aged longissimus lumborum (LL) and ST steaks. There were stimulation × ageing time interactions for pH in both muscles, as LVES reduced the pH at 3 h but did not affect pH at 3 and 6 d post-mortem (P &amp;lt; 0.001 Figure 1). The LVES did not significantly affect the LT color values at 3 d post-mortem (P &amp;gt; 0.05) or in retail display (P &amp;gt; 0.1, Table 1). In the ST, however, there were stimulation × ageing time interactions for a*, b* and chroma measured in retail display, with stimulation increasing all these values at 0 d, whereas there was no effect on a* and chroma and a lesser increase in b* after 4 d (P &amp;lt; 0.001, Table 1). Regardless of ageing time, LVES increased ST L* (P &amp;lt; 0.05) and hue (P &amp;lt; 0.001) in retail display (Table 1). The LVES did not affect LT and ST drip losses (P &amp;gt; 0.1, Table 1), shear force, descriptive sensory attributes and LT purge losses (P &amp;gt; 0.1), but increased ST purge losses (P &amp;lt; 0.05). The LVES increased burnt aroma (P &amp;lt; 0.05) and umami (P &amp;lt; 0.01) and salty (P = 0.075) tastes and decreased bitter taste (P &amp;lt; 0.01) and green-hay flavor (P &amp;lt; 0.05) in the LL, but did not affect ST flavor (P &amp;gt; 0.1; Table 2). Overall, LVES had muscle-specific effects with improvements in ST retail color and LL flavor profile.

Effects of maternal contact and positive human contact during lactation on pork quality: Positive human contact to piglets during lactation improves pork loin muscle pH

Enhancing stress resilience through the early life period in pigs could potentially improve pork quality. It was hypothesised that pigs receiving maternal contact or positive human contact during lactation would have improved carcass and pork quality. Seventy-nine mixed-sex pigs were selected from a 2 × 2 factorial randomised block design for treatments maternal contact (MC+) / reduced maternal contact (MC-); and positive human contact (HC+) / control (HC-). Modified farrowing crates were utilised to reduce maternal contact (MC-). Litters in the HC+ treatment received five minutes of daily positive human interaction (stroking). Treatments ceased at 22 days of age (weaning) and pigs were slaughtered after 21 weeks of age. The m. longissimus thoracis et lumborum pH was higher in HC+ than HC- pigs (P < 0.05) during chilling, from 90 min post slaughter. No HC effects (P > 0.05) were observed for cortisol or haptoglobin concentration, hot carcass weight, P2 backfat, carcass scratches, colour, drip loss, cook loss and shear force. MC+ tended (P < 0.086) to increase carcass weight, P2 and carcass scratch score compared to MC-, but no further impacts were observed. The impact of positive human contact during early life was observed 20+ weeks after treatment with reduced pH decline, potentially indicating a reduction in pre-slaughter stress, however there were no further impacts on pork quality. There is evidence that maternal contact is important for lifetime growth performance of pigs but the impacts on stress resilience are less apparent.

Comparative study of dietary selenium sources on gilthead seabream (Sparus aurata): Growth, nutrient utilization, stress response and final product quality

Selenium (Se) is a crucial trace mineral in human nutrition, known for its various health benefits, including the enhancement of antioxidant defenses. Enrichment of fish fillets with Se is seen as an interesting strategy to reduce the risk of Se deficiency in human diets. While inorganic sources have been traditionally used to supplement Se in fish diets, organic Se forms have demonstrated superior bioavailability and efficacy in managing oxidative stress and tissue retention rates compared to their inorganic counterparts.The main objective of this study was to assess the performance, stress resistance, and product quality of gilthead seabream (Sparus aurata) in response to diets supplemented with 0.2 mg kg−1 of Na2SeO3 (CTRL), Zn-L-SeMet (AVSe) or OH-Se-Met (ORGSe), complying therefore with the European Food Safety Agency (EFSA) maximum allowed supplementation of organic Se (0.2 mg kg−1). Diets were formulated to be similar in their protein (48% DM) and lipid content (17% DM), and hand-fed to apparent satiety to quadruplicate groups of 20 fish (initial body weight ∼ 75 g) gilthead seabream juveniles for 137 days. Fish were kept in a recirculating saltwater system (salinity 35‰, 22 ± 1 °C) until they reached commercial size (>250 g). At the end of the growth trial, all fish were individually weighed and measured, with 4 fish per tank sampled for whole-body composition analysis. Fillet yield, muscle lipid and mineral composition, and hepatic oxidative stress indicators were assessed (n = 12). Lipid peroxidation, muscle pH, water-holding capacity (WHC), color, and texture were evaluated on days 7 and 14 (n = 8), while sensory analysis was conducted on 20 fish. Additionally, 12 fish per treatment were subjected to overcrowding (100 kg m−3) for 5 min and air exposure for 1 min. After a 1-h recovery period, plasma and liver samples were collected from these fish, and results were compared to those of the non-stress group. All diets yielded equivalent growth performance, ensuring low feed conversion ratio. Fish fed the AVSe diet exhibited higher whole-body protein content compared to those fed the CTRL diet. Regarding mineral utilization, increased Se retention and gain in fish fed AVSe and ORGSe diets led to higher Se content in these fish compared to the CTRL. Additionally, the AVSe diet has also resulted in significantly increased Se deposition in the muscle compared to the other tested Se sources, contributing with 34% of the Se Daily Recommended Intake (DRI). The assessed flesh quality parameters and overall consumer acceptance did not reveal significant differences among the groups. Exposure to an acute stress was found to decrease the activities of Glutathione reductase and glutathione peroxidase, which in turn has increased the level of oxidized glutathione, particularly in the AVSe group. Compared to OH-Se-Met and Na2SeO3, Zn-L-SeMet was more effective in promoting response to stress and nutritional value of gilthead seabream as an important source of protein and Se in human diet.

Effect of Early Ciprofloxacin Administration on Growth Performance, Meat Quality, Food Safety, and Metabolomic Profiles in Xueshan Chickens.

To investigate the effects of early administration of ciprofloxacin (CIP) on Xueshan chickens, in this study Xueshan chickens were measured for growth performance, tested for drug residues, evaluated for meat quality, and muscle metabolism changes were explored using a non-target metabolomics approach. Experimental findings revealed that early CIP use did not significantly impact the overall growth rate of Xueshan chickens (p > 0.05). However, notable alterations in meat quality were observed: the CIP-treated group exhibited a significant decrease in muscle pH (pH1 and pH24) and a marked increase in drip loss and moisture content (p > 0.05). No CIP residues were detected in muscle tissue. Untargeted metabolomics analyses unveiled significant alterations in the metabolic profile of market-age chickens following CIP treatment. Both functional enrichment and metabolic network analyses indicated significant effects on the ko01120 (microbial metabolism in diverse environments) and ko00350 (tyrosine metabolism) pathways, implying that CIP treatment may influence chicken meat quality by modulating microbial communities and amino acid metabolism. This study provides a crucial foundation for understanding the impact of antibiotics on meat quality and metabolism in poultry production, offering scientific insights for optimizing antibiotic-use strategies and safeguarding poultry product quality.

The individual and combined effect of DHA and high-fat diet on flesh quality, antioxidant capacity and myofiber characteristics of grass carp (Ctenopharyngodon idellus)

The impact of a high-fat diet (HFD) on the meat quality of farmed fish is a subject of considerable interest among researchers. While docosahexaenoic acid (DHA) is recognized for enhancing growth performance and muscle mass in fish, its potential to mitigate the adverse effects of HFD on meat quality remains uncertain. This study examined the nutritional value, textural properties, and muscle characteristics of grass carp (Ctenopharyngodon idellus) fed varying levels of DHA (0.0%, 0.5%, and 1.0%) under either a regular fat diet (5.0% lipid) or an HFD (10.0% lipid) for a period of eight weeks. Results indicated that the addition of DHA to both the normal fat diet and HFD significantly improved the nutritional and sensory qualities of fish fillets, increasing crude protein, polyunsaturated fatty acid (PUFA), and collagen content while preserving optimal muscle hardness and pH levels. The HFD group exhibited diminished antioxidant capacity, reduced sarcomere length, and mitochondrial structural damage, all effectively ameliorated through DHA supplementation. Moreover, dietary DHA supplementation at both lipid levels upregulated the expression of genes associated with myogenesis and protein synthesis. A two-way ANOVA revealed significant interactions between dietary DHA and lipids, influencing muscle pH, fatty acid composition, myofiber characteristics, antioxidant capacity, and gene expression related to muscle growth and protein synthesis. In conclusion, DHA supplementation can effectively mitigate the deterioration of fish flesh quality induced by HFD.

Relationship between the pH of semispinalis capitis muscle and the quality properties of pork shoulder butt and belly slices

This study investigated the relationship of carcass characteristics such as hot carcass weight and back fat thickness (BFT) and the pH of semispinalis capitis (SC) with the cooking loss (CL) of pork shoulder butt and the CL and Warner–Bratzler shear force (WBSF) of belly. BFT was correlated with the CLs of the butt slices (rs = −0.30) and the belly slices (rs = −0.27 to −0.32). The pH of the SC muscle showed a correlation with the CLs of the butt slices (rs = −0.45) and the belly slices of the 6th and 11th thoracic vertebrae (rs = −0.28 to −0.33). Additionally, the correlations (rs = 0.62 to 0.77) were observed in the CLs among the belly slices. However, the WBSF of the belly slices did not show correlations with others. Therefore, the pH of the SC muscle as well as BFT can be used to obtain information on the CL of shoulder butts and bellies in carcasses.

Effects of long-time and short-time heat stress on the meat quality of geese

This investigation sought to reveal the effects of heat stress on the meat quality of geese. Wuzong geese were subjected to heat stress at 35°C for 25 d or 4 h to examine different heat stress time on meat quality. Short-time heat stress reduced muscle drip loss and meat color L* value while increasing pH value and meat color a* and b* values. Long-time heat stress decreased body weight and increased leg muscle pH value and meat color b* value. Amino acid profile of geese breast muscle revealed that both LHS and SHS can induce L-Cystine but reduced L-Cystathionine, which were positive correlated with cooking loss and meat color lightness, respectively. Lipidome analysis indicated that heat stress would alter the synthesis of unsaturated fatty acids, and the difference between LHS and SHS on lipids mainly focused on Hex1Cer and TG. Non-target metabolome analysis indicated effects of heat stress on Glycerolipid metabolism, Arachidonic acid metabolism, and Pyrimidine metabolism. Proteome analysis showed that heat stress mainly affects cellular respiration metabolism and immune response. These findings highlight the diverse effects of heat stress on meat quality, amino acid composition, lipidome, metabolome, and proteome in geese.

Assessing Individual Muscle Characteristics to Enhance Frozen-Thawed Meat Quality.

This study assessed previous research aimed at mitigating the adverse effects of freeze-thawing on meat quality. Specifically, it focuses on assessing the physicochemical alterations in meat resulting from freezing, freeze-thawing, or technologies to minimize these alterations. Recent studies have focused on conventional freeze-thaw technology applicable across various livestock species and muscle types. However, recent research has indicated the necessity for developing freeze-thaw technology considering the unique characteristics of individual muscles. In this review, we summarize previous studies that have compared alterations in the physicochemical properties of primary muscles owing to freezing or freeze-thawing. Despite the introduction of various technologies to significantly reduce the adverse effects on meat quality resulting from freeze-thawing, it is essential to consider the unique characteristics (proximate composition, pH, and muscle fiber characteristics) of individual muscles or cuts to develop enhanced the freeze-thaw processing technology.

Personalized and muscle-specific OXPHOS measurement with integrated CrCEST MRI and proton MR spectroscopy

Creatine chemical exchange saturation transfer (CrCEST) MRI is an emerging high resolution and noninvasive method for measuring muscle specific oxidative phosphorylation (OXPHOS). However, CrCEST measurements are sensitive to changes in muscle pH, which might confound the measurement and interpretation of creatine recovery time (τCr). Even with the same prescribed exercise stimulus, the extent of acidification and hence its impact on τCr is expected to vary between individuals. To address this issue, a method to measure pH pre- and post-exercise and its impact on CrCEST MRI with high temporal resolution is needed. In this work, we integrate carnosine 1H- magnetic resonance spectroscopy (MRS) and 3D CrCEST to establish “mild” and “moderate/intense” exercise stimuli. We then test the dependence of CrCEST recovery time on pH using different exercise stimuli. This comprehensive metabolic imaging protocol will enable personalized, muscle specific OXPHOS measurements in both healthy aging and myriad other disease states impacting muscle mitochondria.