Mechanisms of water-holding capacity of meat: The role of postmortem biochemical and structural changes

Physicochemical, microstructural, and sensory attributes of frozen Buffalo loins treated with sodium tripolyphosphate and sous-vide cooking

This study investigates the effects of sous-vide cooking with varying concentrations of sodium tripolyphosphate (STPP) on the physicochemical properties (pH, cooking loss, water-holding capacity, colour properties, and shear force), lipid oxidation (thiobarbituric acid reactive substances, TBARS), secondary protein structures (Fourier transform infrared, FTIR), microstructure (scanning electron microscope, SEM), and sensory attributes (descriptive analysis) of frozen buffalo loins. Commercial buffalo loins (Black Gold) imported from India were used as samples (n = 15). They were sliced into steaks of 2 cm thickness, injected with 0 %, 0.15 %, and 0.3 % STPP, vacuum-sealed, and tumbled at 4 °C for 1 h. Subsequently, they were cooked sous-vide at 60 °C for 6 h. Results indicated that STPP significantly increased pH, reduced cooking loss, and enhanced water-holding capacity. Higher STPP concentrations increased lightness and redness while lowering shear force values. TBARS reached 2 mg MDA/kg in the 0 % STPP group by day 7, while buffalo loins with 0.15 % and 0.3 % STPP reached this level by days 21 and 28, respectively. FTIR showed similar secondary protein structure patterns in buffalo loins with 0.15 % and 0.3 % STPP, while the untreated sample had irregular patterns. SEM analysis revealed porous muscle fibres and thinner perimysium in the 0.3 % STPP samples, indicating greater tenderness. Sensory evaluation confirmed improvement in visual appeal, juiciness and aroma with 0.3 % STPP concentration.

The effect of sustainable vacuum packaging selection on the quality, colour stability, and freshness of lamb meat stored chilled for up to 20 weeks

Storage period and packaging type effects on lamb meat were investigated using 384 longissimus lumborum muscles (LL), randomly allocated to 8 storage periods (Week 0, 1, 2, 6, 10, 14, 18, and 20; -1.2 ± 1.1 °C) and 4 packaging types (PACK 1, Eco-tite® Recycle Ready Shrink Bag; PACK 2, Cryovac® Barrier Shrink Bag; PACK 3, a foil pouch; and PACK 4, Biovac™ Recyclable Vacuum Pouch). Analysis demonstrated few storage period effects on lamb meat quality. Shear force was perceivably reduced after Week 1 (P < 0.001); myofibrillar protein solubility increased with storage period (P = 0.004); and purge (P < 0.001), cooking (P < 0.05), and drip loss (P < 0.05) show a reduction in water-holding capacity between Weeks 0-14. Intramuscular fat, crude protein, dry matter, total moisture, and sarcoplasmic protein solubility were not affected by storage period (P > 0.05). The packaging effects on meat quality were somewhat limited to PACK 3. Differences in water holding capacity was most apparent between PACK 1-2 and PACK 3-4, the latter having the highest amount of water loss (P < 0.05). TVC increased with storage period (P < 0.001), but remained > log 7 CFU/g for any treatment combination. TVB-N concentrations increased between Weeks 1-14 (P < 0.001), but remained > 15 mg/100 g. Lamb meat stored for > 6 weeks became unacceptably discoloured (based on a* and brownness indices) increasingly sooner into the 3 d retail display period. These findings support a longer shelf-life for chilled lamb meat.

Effects of dietary grape seed proanthocyanidin extract supplementation on muscle water-holding capacity of finishing pigs

Water-holding capacity (WHC) is essential for both pork quality and industrial economics. Preliminary studies have shown that grape seed proanthocyanidin extract (GSPE) helps reduce drip loss in the longissimus thoracis (LT) muscle of finishing pigs. However, the mechanism by which GSPE affects the WHC of pork remains unclear. This study investigated the improvement in WHC of pork following dietary supplementation with GSPE. The research findings showed that adding GSPE to the diet significantly reduced drip loss, increased the proportion of bound water in the muscle, and improved muscle fiber rupture and separation. GSPE also significantly increased muscle pH value, reduced glycolytic potential, enhanced the expression of calpain-1 and integrin β1, and altered muscle fiber characteristics. In summary, the impact of GSPE on the WHC of LT muscle may be closely linked to the expression of cytoskeletal proteins, calpains, muscle fiber characteristics, and enzymes involved in the glycolysis pathway.

Dose-dependent effects of rumen-protected betaine on the quality characteristics of longissimus Lumborum muscle in fattening lambs during extended freezing storage

This study investigated the effects of rumen-protected betaine (RPB) supplementation on the quality attributes of Longissimus lumborum (LL) muscle in fattening lambs during extended frozen storage. Following the fattening period, 32 lambs were randomly selected for meat quality analysis. The experimental groups were as follows: (1) CTRL (control): no dietary RPB; (2) RPBL: 2 g RPB per head per day; (3) RPBM: 4 g RPB per head per day; and (4) RPBH: 6 g RPB per head per day, during the fattening period. Meat samples were stored at -18 °C for up to nine months, and physicochemical properties, including color, water-holding capacity (WHC), drip loss, cooking loss, Warner-Bratzler shear force (WBSF), lipid peroxidation, and antioxidant enzyme activities, were analyzed at different time points. RPB supplementation improved WHC (P < 0.05), with the RPBH group exhibiting the highest retention of intracellular water throughout storage. Drip and cooking losses were markedly reduced in the RPB-supplemented groups, particularly RPBM and RPBH, indicating improved protein stability and reduced oxidative damage. Additionally, RPB supplementation enhanced meat tenderness, as evidenced by lower WBSF values in treated groups (P < 0.05). Overall, this study highlights RPB as a functional feed additive that enhances meat quality and extends shelf life under frozen conditions. Future research should explore the underlying molecular mechanisms, including oxidative stress markers and proteolytic enzyme activity, to further elucidate RPB's role in meat preservation.

Meat Quality Traits Using Gelatin-Green Tea Extract Hybrid Electrospun Nanofiber Active Packaging

The adverse effects of polyethylene packaging waste on environmental pollution have driven academia to explore biodegradable active packaging (AP) solutions. In the present study, hybrid electrospun nanofiber (HENF) AP was produced using 30% gelatin (GE) combined with 1%, 2%, and 3% green tea extract powder (GTEP), termed HGGTNF. HENF was applied to Hanwoo beef as an AP to assess physicochemical, textural, microbiological, and sensory qualities in comparison to traditional polyethylene packing (PEP). The findings illustrate that the HGGTNF group maintained a significantly (p < 0.05) stable pH (5.71 ± 0.02-5.78 ± 0.01), lower drip loss (DL) (1.15% ± 0.00 to 1.20 ± 0.02%), and cooking loss (CL) (18.13 ± 0.03% to 19.91 ± 0.01%) compared to PEP (pH = 5.66 ± 0.02, DL = 1.21 ± 0.01%, CL = 20.26 ± 0.03%). Moreover, HGGTNF improved oxidative stability, especially at elevated doses (2% and 3%). In HGGTNF groups, there was a decreasing (p < 0.05) trend in thiobarbituric acid reactive substances (TBARS) (0.23 ± 0.01 to 0.26 ± 0.01 mg-MDA/kg), compared to the PEP group (0.29 ± 0.01 mg-MDA/kg). Oxidative stability improved the fatty acid profile, preserved color intensity (Chroma), and inhibited discoloration (h°) in HGGTNF (2% & 3%) compared to PEP. Furthermore, HGGTNF groups had stable meat tenderness and better chewiness than PEP. Stabilization of tenderness was due to diminished cathepsin activity (5822.80 ± 20.16 and 6009.80 ± 3.90 U/mg protein in the HGGTNF 2% and 3% groups, respectively). The HGGTNF 3% sample exhibited a decrease in total coliform counts (TCC) (0.74 ± 0.04 log CFU/g), total viable counts (TVC) (1.38 ± 0.05 log CFU/g), and total yeast and mold count (TYMC) (1.59 ± 0.06 log CFU/g) compared to other groups, indicating efficient antimicrobial efficacy. An increasing (p < 0.05) trend was observed in umami and richness taste traits for the HGGTNF 3% treated sample. The above findings underscore the potential applicability of HGGTNF as AP to enhance beef shelf life and meat quality attributes.

Low-oil corn distillers dried grains with solubles can be fed to pigs up to 16.5% without compromising growth and pork quality

OBJECTIVE

This study aimed to determine the maximum inclusion rate of low-oil corn distillers dried grains with solubles (DDGS) in swine diets with a focus on growth performance and pork quality.

METHODS

A total of 160 crossbred pigs with an initial body weight (BW) of 25.5 kg (standard deviation = 2.5) were randomly assigned to one of 5 dietary treatments in a randomized complete block design with BW and sex as blocking factors to obtain 8 replicates and 4 pigs per pen. The low-oil corn DDGS contained 26.3% crude protein, 24.5% neutral detergent fiber, and 3.7% ether extract. Five experimental diets based on the corn, soybean meal, and wheat were formulated to contain 0%, 10%, 20%, 30%, and 40% of the low-oil corn DDGS for each of 2 phases.

RESULTS

During the overall period, average daily gain, average daily feed intake, and gain-to-feed ratio linearly decreased (p<0.05) as the low-oil corn DDGS inclusion rate increased. A one-slope broken-line analysis showed that the maximum inclusion rate of low-oil corn DDGS in swine diets without compromising gain-to-feed ratio was 16.5% during the overall period. The carcass characteristics were not affected by the inclusion of low-oil corn DDGS up to 40%. The firmness of loin and belly linearly decreased (p<0.05) as the low-oil corn DDGS inclusion rate increased. As the inclusion rate of low-oil DDGS increased, the saturated fatty acid content in both loin and pork belly linearly decreased (p<0.001), whereas the unsaturated fatty acid content linearly increased (p<0.001). The iodine value of lard also showed a linear increase (p<0.001) with increasing the low-oil corn DDGS inclusion rate.

CONCLUSION

The maximum inclusion rate of low-oil corn DDGS in growing-finishing swine diets without detrimental effects on growth performance and pork quality was 16.5%.

The Early Methionine Supplementation of Ewe Lambs (F0) Modifies Meat Quality Traits of the Progeny (F1, Male Fattening Lambs)

Adequate management of replacement ewe lambs (F0) in dairy sheep farms during postnatal life may modify the germline cells, thus promoting transmission of intergenerational effects to the offspring (F1). To test this hypothesis, 18 newborn male lambs (F1), either born from methionine-supplemented ewe lambs (F0 ewe lambs being fed ad libitum with a milk replacer supplemented with 1 g methionine/kg DM) or not supplemented (F0 ewe lambs being fed ad libitum with the same milk replacer with no methionine added), were included in the present study. All the male F1 lambs were managed exactly in the same way along the whole lifespan in order to bring out the differences caused by methionine supplementation of F0 dams. Our data show that the methionine supplementation of dams (F0) during the suckling period did not promote significant (p > 0.05) changes on feed intake, growth rate, or feed efficiency of F1 male lambs during the fattening period. Moreover, the meat chemical composition (proximal, fatty acid profile, and volatile compounds) was similar for both groups (p > 0.05), but the meat of F1-MET lambs presented higher redness and hardness (p < 0.05) when compared to F1-CTRL lambs. The biochemical profile also highlighted significant (p < 0.05) differences in the serum creatinine and calcium content that may be at least partially related to the meat quality traits observed. Overall, all these results suggest that methionine supplementation of lambs (F0) during early postnatal life causes permanent changes in the offspring. This has positive effects, such as achieving a more attractive color of lamb meat (F1) for consumers, and negative effects, such as reduced meat tenderness.

Utilizing drip metabolites and predictive modeling for non-destructive freshness assessment in pork loin

This study validated the use of pork drip metabolites for non-destructive freshness prediction. The pork loin was vacuum-packaged and stored for 27 days at 4 °C. The pH, drip loss, total aerobic bacterial counts (TAB), microbial composition and drip metabolites were examined. LASSO and Random Forest (RF) were selected and used for variable selection, while Ridge regression and Support Vector Regression were utilized to develop predictive models. Validation was performed using leave-one-out cross-validation. LASSO and RF selected 13 and 10 metabolites, respectively. The metabolites selected by each method were trained using Ridge regression and SVR. Each of the four trained models achieved R2 values of over 0.9. In the validation step, the model trained by Ridge regression using drip metabolites selected through LASSO showed the lowest RMSE value of 0.283 log CFU/g. Therefore, selected drip metabolites can be used to predict TAB and microbial composition of pork loin through mathematical modeling.

Insights into the differences of caspase and apoptosis levels in pork longissimus thoracis muscles with different tenderness: A perspective on S-nitrosylation modification

This study investigated the differences of caspase and apoptosis levels in pork with different tenderness from the perspective of S-nitrosylation and further explored their role during pork tenderization. Ten longissimus thoracis muscles selected from 36 individual carcasses based on shear force were divided into high (HT) and low (LT) tenderness groups (n = 5), respectively. Results demonstrated that total nitric oxide synthase activity and protein S-nitrosylation levels of LT group were higher than HT group, while myocyte apoptosis levels were lower in LT group (p < 0.05). Additionally, LT group possessed a lower caspase-3 activity while a higher abundance of intact caspase-3 and greater S-nitrosylation levels of cleaved caspase-3 (p < 0.05). However, none of the above differences were found in caspase-9 (p > 0.05). The lower tenderness in LT group might be associated with reduced caspase-3 activity resulted from increased S-nitrosylation levels of its active subunits, which delayed myocyte apoptosis and lowed the degradation of desmin and troponin T.

Influence of carcass chilling time on the progression of rigor mortis, carcass characteristics and physicochemical properties related to the colour and tenderness of longissimus thoracis et lumborum and biceps femoris muscles in Botucatu rabbits

The objective of this study was to characterize the progression of rigor mortis and evaluate the influence of chilling time on carcass characteristics, colour, and tenderness of Botucatu rabbit meat in both males and females. The muscles analyzed were the longissimus thoracis et lumborum (LTL) and biceps femoris (BF). As chilling time progressed, weight loss due to chilling increased (P < 0.001), whereas weight loss due to thawing (P = 0.035) and volume of exudate post-thawing (P = 0.022) decreased. Cold carcass yield remained stable for 18 h of chilling, with greater (P < 0.001) values for males. The colour parameters L*, a* and b* were significantly influenced by sex and chilling time. Rigor mortis began at 1.5 h post-mortem, was established between 4.5 and 6 h, and resolved at 18 h of chilling. Biceps femoris showed greater (P < 0.001) shear force at 0 h and 4.5 h, with reduced (P < 0.001) tenderness in males compared to females. Sarcomere length was shorter (P < 0.001) at 24 h in BF and from 18 h in LTL. Myofibrillar fragmentation index of both muscles, and water holding capacity of BF increased (P < 0.001) with chilling time. Therefore, it is concluded that chilling the carcasses for 18 h prior to freezing results in reduced weight losses, increased luminosity and tenderness of Botucatu rabbit meat.

Effects of atmospheric cold plasma treatment mode on muscle quality and bacterial community of red shrimp during cold storage

Atmospheric cold plasma (ACP), known for its safety, non-thermal processing, and energy efficiency, is especially effective for preserving perishable items such as seafood. However, excessive use of ACP may cause oxidation and sensory quality deterioration, which limits its application in the seafood industry. Thus, optimizing ACP treatment modes to balance sterilization efficiency with minimal oxidative effects is essential. This study aims to explore the impact of different ACP treatment modes (cyclical and one-time treatment) on the muscle quality and bacterial community of red shrimp during cold storage. The results indicated that on day 0 of storage, compared to the blank group and the one-time treatment group, the cyclical treatment significantly reduced the total viable count in red shrimp (p < 0.05). However, no significant differences were observed in centrifugal loss, cooking loss, textural properties, total sulfhydryl content, or Ca2+-ATPase activity (p > 0.05). By day 8, both ACP treatment modes significantly improved the protein quality of red shrimp. Compared with the one-time treatment, cyclical treatment reduced the abundance of Aliivibrio (57.24 %), Pseudoalteromonas (97.34 %), and Psychrobacter (59.07 %) in the bacterial community and delayed bacterial succession (especially Aliivibrio salmonicida, Psychrobacter cibarius, and Pseudoalteromonas nigrifaciens), slowing down the degradation of protein quality. Specifically, in the cyclical treatment group, cooking loss was reduced by 7.01 %, and improvements were observed in hardness, total sulfhydryl content, and Ca2+-ATPase activity, which increased by 8.93 %, 17.54 %, and 5.63 %, respectively. Overall, this study demonstrates that the ACP cyclical treatment mode has greater potential in preserving the freshness of seafood.

Effects of ohmic heating thawing under an appropriate electric field on the quality and structure of duck breast meat

Ohmic heating thawing (OHT), as a novel thawing technique, possesses distinct advantages and is currently garnering attention from researchers. We have investigated the effects of OHT on the structure and protein quality of duck breast meat. Compared to conventional thawing (CT) methods (water thawing [WT], 20 ± 0.5°C; air thawing [AT], 20 ± 0.5°C), OHT (10, 15, and 20 V/cm) has been shown to enhance thawing efficiency, reducing thawing time by 28%-86% (p < 0.05), lowering thawing loss rates by 2.55% (p < 0.05), and resulting in milder protein oxidation with better preservation of protein secondary structures. Microscopically, OHT resulted in minimal damage to myofibrils in the duck breast meat. In this experiment, the optimal thawing electric field strength for duck breast was 15 V/cm. Moreover, the efficacy of OHT also relies on variations in voltage, with the most suitable thawing voltage determined by the specific characteristics of the material. These findings reveal the potential of OHT for thawing meat products. PRACTICAL APPLICATION: Ohmic heating thawing (OHT) shortens thawing time and enhances thawing efficiency while reducing thawing loss rates. It has a minimal impact on proteins and a minor effect on muscle fiber structure.

Ante-mortem glutathione peroxidase 4 inhibition by RSL3 affects post-mortem meat quality in broiler chickens

1. This study investigated the role of glutathione peroxidase 4 (GPX4), a key regulator of ferroptosis, a form of programmed cell death, in muscle biochemistry and meat quality, utilising broiler chickens whose ante-mortem GPX4 activity was inhibited pharmacologically.2. Male broilers were divided into two groups, each receiving ante-mortem administration of the GPX4 inhibitor, Ras-selective lethal 3 (RSL3), or a vehicle only. After slaughter, breast muscles were collected and stored for 48 h. The expressions of ferroptosis-related genes, glutathione levels, pH, colour and water-holding capacity were evaluated at multiple time points during the storage period.3. The RSL3 treatment decreased the expression of GPX4 and ferritin heavy chain 1, which are negative regulators of ferroptosis, while it increased the expression of a ferroptosis accelerator, acyl-CoA synthetase long chain family member 4. The ratio of reduced to oxidised glutathione was significantly decreased in the RSL3 group. The RSL3 treatment decelerated post-mortem pH decline and colour changes, such as a decrease in L* and an increase in a* were observed in the RSL3 group. In addition, the RSL3 group showed increased levels of water-holding capacity.4. These findings suggested that ante-mortem GPX4 activity plays a role in determining meat quality, implying the possible involvement of ferroptosis in the mechanism by which skeletal muscle is converted after slaughter into meat that is eaten.

Cysteine-induced disulfide cleavage enhances the solubility of alkali-treated pea protein and its elasticity contribution in low-salt hybrid meat gels

This study investigated the effectiveness of cysteine in improving the functional properties of pea proteins within low-salt myofibrillar protein (MP) gels. Cysteine treatment, at a concentration of 3.3 mM/g protein, cleaved 71-82 % of the disulfide bonds in native and pH-shifted pea protein isolates (PPIN and PPIpH), which increased the solubility and hydrophobicity of PPIpH. PPIN showed slight changes, primarily an increase in tryptophan fluorescence. The cleavage of disulfide bonds improved the hardness, elastic component (G'), and network integrity of hybrid gels. When combined with transglutaminase, the MP + PPIpH gel reached its maximum hardness (0.38 N) at a cysteine concentration of 1.7 mM/g protein. SDS-PAGE patterns and gels treated with additional N-ethylmaleimid confirmed the involvement of cysteine-treated PPI in the gel matrix. Consequently, cysteine-mediated disulfide bond disruption effectively modifies pea proteins, rendering them a more suitable functional ingredient for enhancing the texture of low-salt meat products.

Identification of Biomarkers for Meat Quality in Sichuan Goats Through 4D Label-Free Quantitative Proteomics

The Nanjiang Yellow Goat (NJYG), Jintang Black Goat (JTBG), and Jianzhou Da'er Goat (JZDEG) are representative local goat breeds for meat production in Sichuan Province, China. This study conducted a comprehensive evaluation of the meat quality of the longissimus dorsi muscle of three goat breeds. Variations in meat quality were observed in terms of meat pH, color, ash and fat content, water activity, and muscle fiber structure. Quantitative proteomics analysis was employed to identify biomarkers for goat meat quality, revealing hundreds of differentially expressed proteins among three goat breeds. KEGG enrichment analysis revealed enriched pathways including oxidative phosphorylation, thermogenesis, citrate cycle (TCA cycle), fatty acid degradation and metabolism, as well as valine, leucine, and isoleucine degradation. Moreover, weighted protein co-expression network analysis and protein-protein interaction analysis uncovered valuable biomarkers, including GSTM3, NDUFS, OGDH, ACO2, HADH, ACAT1, ACADS, ACAA2, HSPG2, ITGA7, PARVB, ALDH9A1, ADH5, and LOC102190016, for assessing goat meat quality. This investigation highlighted the disparities in meat quality among local goat breeds in Sichuan, China, and provided insights into underlying biological pathways and valuable biomarkers for goat meat quality.

Effect of different Lys/Met ratios in a low-protein diet on the meat quality of Tibetan sheep: A transcriptomics- and metabolomics-based analysis

This study integrated the the effects of dietary Lys/Met ratio in a low protein diet on the meat quality in Tibetan sheep. A total of 90 weaned Tibetan sheep, 2 months old with initial weight of 15.37 ± 0.92 kg were randomly divided into 3 treatments, which were supplemented with Lys/Met ratio at 3 (LP-H), 2 (LP-M), and 1 (LP-L) in the basal diet (10 % crude protein), respectively. After slaughter (150 days of age), the growth performances and meat quality of longissimus dorsi muscle were evaluated. The LP-L group showed significantly higher final body weight compared to the LP-M group (P < 0.05). Serum albumin and total protein levels were significantly higher in the LP-L group than in the LP-H group (P < 0.05). Furthermore, meat from the LP-L group had significantly higher protein, calcium, and vitamin E content compared to the LP-M group (P < 0.05). Transcriptomic analysis revealed 3,479 differentially expressed genes enriched in pathways related to muscle growth, energy metabolism, and signaling transduction. Metabolomic analysis identified 771 differential metabolites, significantly enriched in ABC transporters, beta-alanine metabolism, and taste transduction pathways. Integrated analysis highlighted the upregulation of the ABCD4 gene and L-valine metabolite in the LP-L group, contributing to improved phenotypic traits. These findings provide molecular insights into the regulatory mechanisms underlying the effects of dietary Lys/Met ratios on Tibetan sheep meat quality and offer a basis for developing nutritional strategies to enhance premium meat production.

Dose-dependent effects of dietary curcumin nano-micelles on the quality characteristics of Longissimuslumborum muscle in fattening lambs during extended freezing storage

The current study evaluated the impact of dietary curcumin nano-micelles (CNM) on the quality of Longissimus lumborum (LL) muscle in lambs during long-term freezing storage. Thirty-two crossbred male lambs were assigned into four groups receiving 0, 20, 40, or 80 mg CNM daily over a 97-day fattening period. Meat samples were analyzed for quality attributes over nine months of freezing. Supplementation with CNM, especially at 40 mg, improved carcass characteristics and reduced saturated and branched-chain fatty acids. Notably, CNM preserved meat color, enhanced water-holding capacity, and reduced drip and cooking losses, with the 40 mg dosage showing the most significant effects. While meat tenderness was unaffected, CNM exhibited antioxidant properties by reducing lipid peroxidation and stabilizing enzyme activities and total antioxidant capacity. These results indicate that CNM, particularly at 40 mg, enhances meat quality during long-term freezing, especially after six months. The findings underscore CNM's potential as a natural additive to improve lamb meat stability and quality during extended frozen storage, with implications for both the meat industry and consumer satisfaction.

Physicochemical and conformational changes of krill myofibrillar protein induced by two-stage thermal treatment and their relationship with muscle texture

To preserve the juiciness of Krill muscle, a simple but robust strategy of two-stage thermal treatment (40-70 °C followed by 90 °C) was explored while the alterations in muscles, physicochemical and conformational changes of myofibrillar proteins were investigated. Conventional one-stage boiling treatment was considered as the control. The results revealed that the actomyosin dissociation was most pronounced preheated by 50 °C, supported by higher content of actin and increased surface hydrophobicity with a substantial drop in α-helix. The disulfide bonding for the control and 70 °C group was significantly higher, indicating a pronounced oxidation. The most robust affinity for water of krill was observed when subjected to preheating at 50 °C, exhibiting the wildest separations between muscle bundles and well-preserved fibers, while severe contraction of muscle bundles was observed with fracturing and minor gaps. The findings provide direct proof to support the feasibility of implementing a preheating thermal processing method for krill.

The Mechanism of Quality Changes in Grass Carp (Ctenopharyngodon idella) During Vacuum-Assisted Salting Brining with Physicochemical and Microstructural View

This study investigated the effects of vacuum impregnation (V) and atmospheric pressure impregnation (C) on the quality and microstructure of grass carp (Ctenopharyngodon idella) fillets during a 120 min brining period under 5.8% NaCl (w/v) and 4 °C. Vacuum impregnation significantly enhanced brining efficiency, achieving higher salt content (2.01%) and accelerated mass transfer kinetics, as evidenced by Peleg model parameters. Both treatments improved the water-holding capacity (WHC), increasing from 80.16% to 91.47% (C) and 89.92% (V), while reducing free water proportion. A microstructural analysis revealed a reduction in extracellular space in fillets, which further affected the fillet WHC and texture. Vacuum brining also mitigated lipid oxidation, yielding lower thiobarbituric acid-reactive substances (TBARSs: 0.237 mg MDA/kg). Texture analysis indicated reduced hardness and increased springiness/cohesiveness in fillets. Despite a slight decrease in lightness, vacuum-assisted brining preserved sensory quality and aligned with low-salt dietary trends. These findings underscore vacuum technology's potential to optimize brining efficiency and product quality in industrial applications.

Rheological and Gelling Properties of Chicken-Mushroom Hybrid Gel for Flexitarian-Friendly Functional Food Applications

Hybrid gels combining chicken and mushroom offer innovative functional food choices, catering to the growing demand for flexitarian-friendly products. These gels reduce meat content while enhancing dietary fiber, bioactive compounds, and sustainability. This study examined the effects of split gill mushroom (Schizophyllum commune) powder (SGM) substitution (0%, 25%, 50%, and 75%, w/w) for Ligor chicken meat in hybrid gels, focusing on rheological and gelling properties. The 25% SGM gel demonstrated optimal performance in terms of rheology, texture, microstructure, pH, water-holding capacity, and color. At this level, hybrid gels exhibited superior gelation properties, demonstrating elasticity dominance, as indicated by a higher storage modulus (G') than loss modulus (G″), along with stable cohesiveness and unaffected springiness (p > 0.05). However, hardness, gumminess, and chewiness were significantly lower than the control (p < 0.05). Higher SGM levels (50-75%) markedly weakened the gels, reducing viscoelasticity, increasing porosity and water release, and causing discoloration. These findings highlight 25% SGM as an optimal level for hybrid meat gels, maintaining product quality while promoting sustainability in the meat industry.

Hypoxia-inducible factor-1α promotes ferroptosis by inducing ferritinophagy and promoting lactate production in yak longissimus thoracis et lumborum postmortem

Ferroptosis has emerged as a novel, crucial regulator of meat quality in the postmortem hypoxia environment, with its role in mediating protein oxidation and cell death. However, the interaction between ferroptosis and the hypoxia response, especially the involvement of hypoxia-inducible factor-1α (HIF-1α), remains poorly studied. This study aimed to characterize whether HIF-1α influences ferroptosis, and, if so, explore the underlying mechanisms involved. The results showed that ferroptosis mediated by HIF-1α negatively impacts meat color and water holding capacity (WHC) but improving tenderness. Inhibition of HIF-1α by 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1) reduced ferroptosis, as evidenced by lower lipid ROS levels, malondialdehyde (MDA), along with higher glutathione (GSH) levels compared to the control (P < 0.05). Additionally, inhibition of HIF-1α shifted iron homeostasis towards decreased uptake via downregulation of transferrin receptor 1 (TfR1) and induced export/storage via upregulation of ferroportin (FPN) and ferritin heavy chain (FTH) (P < 0.05). The relative expression of the ferritinophagy mediator nuclear receptor coactivator 4 (NCOA4), LC3-II/LC3-I ratio, and ATG were inhibited by YC-1 (P < 0.05), these findings suggest a general decrease in ferritinophagy associated with HIF-1α inhibition. YC-1-treated samples exhibited significantly diminished lactate accumulation and lactate dehydrogenase (LDH) activity compared to the control (P < 0.05). Unexpectedly, the inhibition of ferroptosis caused by YC-1 was further amplified by lactate enhancement, suggesting that lactate can exert its suppressive effects on ferroptosis independently of HIF-1α. Collectively, these findings demonstrate that HIF-1α drives ferroptosis by regulating iron metabolism, while lactate inhibits ferroptosis in a HIF-1α-independent manner. Overall, the HIF-1α mediated ferroptosis of postmortem yak muscle had a negative impact on WHC and color, while as a contributing factor of tenderness.

Effects of water flow treatment on muscle quality, nutrient composition and volatile compounds in common carp (Cyprinus carpio)

This study explored the effects of water flow on the muscle quality, nutrient composition, and volatile compounds in Cyprinus carpio. Fish were exposed to three treatments: sustained water flow (SG, 1 bl/s, 24 h/d), intermittent water flow (IG, 1 bl/s, 8 h/d), and control group (CG, 3 cm/s). Results indicated that SG improved water-holding capacity, muscle fiber density, hardness, and chewiness, while IG enhanced gumminess, springiness, and resilience. Nutritionally, CG exhibited higher crude lipid content and the highest levels of ΣSFA. Conversely, SG showed elevated ∑EPA + DHA and ω-3 fatty acid levels compared to IG. Volatile compound analysis demonstrated that CG contained higher levels of aldehydes and alcohols, associated with off-flavors, whereas IG and SG produced fresher and sweeter aroma profiles, enhancing sensory quality. These findings provide valuable insights into improving the muscle quality, nutritional value, flavor characteristics, processing, and preservation of common carp through water flow treatment.

Exploring the potential of Mon-Pu (Glochidion wallichianum) leaf extract as a natural antioxidant for Ligor chicken meat gel: Impact on gelation functionality and oxidative stability

This study evaluated the antioxidant potential of Mon-Pu (Glochidion wallichianum Mull. Arg.) leaf extract (MPLE) as a natural antioxidant in Ligor chicken meat gels. The investigation focused on the impacts on gelation functionality and oxidative stability during refrigerated storage. MPLE with 21.16 mg/100 g of extractable phenolic compounds and antioxidant potency (DPPH• scavenging activity, ABTS•+scavenging activity, and ferric reducing antioxidant power (FRAP) at 2.79, 21.13, and 3.20 mmole TE/g, respectively) was applied during thermal-induced gel preparation at different concentrations (0 %, 0.01 %, 0.1 %, and 1 %) in comparison with 1 % gallic acid, a reported key phenolic compound in MPLE, based on the total weight of the meat sample. MPLE at concentrations of 0.1-1 % effectively reduced lipid oxidation in Ligor meat gel during storage. Additionally, MPLE at 0.1 % inhibited protein oxidation, preserving the physical and textural qualities of meat gels during processing and refrigerated storage. Notably, MPLE at 0.1 % proved to be the most beneficial, retaining gel properties, enhancing water-holding capacity, stabilizing color, and reducing oxidative degradation. These findings indicate that MPLE, at an optimal concentration of 0.1 %, has significant potential as a natural preservative, providing a safer and more effective alternative to synthetic additives for maintaining gel properties and preserving oxidative stability of chicken meat products, particularly Ligor chicken meat gel.

Exploring variances in meat quality between Qingyuan partridge chicken and Cobb broiler: Insights from combined multi-omics analysis

Previously, animal breeding prioritized enhancing key economic traits to improve production efficiency, leading to a gradual difference in meat quality. However, the genetic factors influencing meat quality remain unclear. To identify key genetic pathways contributing to meat quality, native Chinese yellow-feathered chicken (Qingyuan Partridge Chicken, QPC; female, n=10), and commercial chicken broiler (Cobb broiler, CB; female, n=10) were used for meat quality assessment through metabolomics, proteomics, and phosphoproteomics sequencing. The results show that QPC had lower pH (93.12%), shear force (81.46%), cooking loss (69.29%), moisture content (93.24%) and muscle fiber area (46.04%), but higher meat color values (a*(163.65%) and b*(250.27%)), drip loss (146.32%), and intramuscular fat content (382.01%) than CB (p < 0.05). Metabolomic, proteomic, and phosphoproteomic analyses were jointly conducted, revealing significant differences in energy metabolism strategies. Higher glycolytic enzyme activity was observed in QPC (ENO1, GAPDH, GPI, PFKM, PKM, and TPI1, p < 0.05), while more energetic phosphate compounds were stored in CB. CB had higher Na+/K+ Pump protein abundance (SCN4A, LOC107051305, ATP1B4, ATP12A, ATP1A1, and ATP1A2, p < 0.05) and phosphorylation (ATP1A2-Ser662, p < 0.05) and Ca2+ channel protein abundance (ATP2B4, SRL, CACNB1, CACNA1S, CACNA2D1, CAMK2G, LOC107050717 and TNNC2, p < 0.05) than QPC. In QPC, CAMKII autophosphorylation activated downstream protein and increased Ca2+. These results suggest CB is more contractile than QPC, contributing to meat quality between CB and QPC.

Impact of high pressure impregnation and air drying on the quality of Dosidicus gigas slices

Humboldt squid (Dosidicus gigas) is the most abundant cephalopod in the fishing industry, and its high nutritional and organoleptic properties make it a go-to food product for consumers. Therefore, developing new processing techniques seems imperative to minimize quality deterioration and provide products with appropriate characteristics. The study aimed to determine the effect of high-pressure impregnation (HPI) pretreatment on hot air-drying kinetics and the quality of Humboldt squid slices. Various pressures, times, and concentrations of osmotic solution during HPI were evaluated, followed by drying at 40 and 60 °C. The HPI pretreatment reduced the drying time by around 26% when dried at 40 °C, and only 18% when dried at⋅ 60 °C compared with unpretreated samples. The Weibull, Page, and Logarithmic models were considered for experimental drying curve modeling. Diffusion coefficient values varied from 3.82 to 6.59 × 10-9 m2/s for all drying conditions. Moreover, the color, texture, and water-holding capacity were determined. Rehydration capacity values increased due to less damage to cellular tissue than the control (HPI-untreated dried samples). Also, scanning electron microscope (SEM) images showed a compacted structure of HPI-dried squid samples. Overall, HPI proved to be a beneficial pretreatment as it reduced drying time and improved the quality characteristics of Humboldt squid.

Effect of fructo-oligosaccharides on growth performance and meat quality in broilers

This study investigated the fructo-oligosaccharides (FOS) on growth performance and meat quality in broilers. Total 160 Xianghuang broilers aged 2 months were randomly assigned into 2 groups, CON (control), FOS (supplemented 0.5% fructo-oligosaccharides in diet). After 38 days, the breast, thigh muscle and liver samples were collected for further analysis. Results showed that no significant effect of 0.5% FOS on growth performance such as average daily gain (ADG), average daily feed intake (ADFI) or feed-to-gain ratio (F:G) were observed (P > 0.05). Broilers in FOS group had a yellower breast than that in CON group (P < 0.05). Breast pH45min and thigh pH24h value of FOS group were greater than that in CON group (P < 0.05). Max shear force and work of shear of cooked breast (pectoralis major) muscle was lower in FOS group compared with CON group (P < 0.05). Hardness (P = 0.065), fracturability (P = 0.063), gumminess (P = 0.079), chewiness (P = 0.080) of cooked thigh meat tended to be higher in FOS group compared to the CON group. Addition of 0.5% FOS resulted in lower thigh total superoxide dismutase (T-SOD) activity compared to CON group (P < 0.05). The malonaldehyde (MDA) concentration (P = 0.066) of breast muscle tended to be lower in FOS group compared with CON group. There was an increasing trend for total antioxidant capacity (T-AOC) activity of thigh muscle in FOS group compared to CON group (P = 0.053). Relative mRNA expression of breast catalase (CAT), superoxide dismutase 1 (SOD1), thioredoxin reductase 1 (TXNRD) were up-regulated by FOS supplementation compared with CON group (P < 0.05). In conclusion, FOS can be utilized at 0.5 % to improve meat quality such as elevating pH value, yellowness and decreasing max shear force of muscle through enhancing the antioxidant activity in broilers.

Spatial metabolomics, LC-MS and RNA-Seq reveal the effect of red and white muscle on rabbit meat flavor

Meat quality is a key factor influencing consumer purchasing decisions. Muscle composition consists of various types of myofibers (type I and type IIa, IIb, IIx myofibers), and the relative composition of fiber types has a significant impact on the overall biochemical properties and flavor of fresh meat. However, the relationship between biochemical changes in myofibers and their impact on meat quality remains underexplored. In this study, we compared the differences in meat quality by examining different muscles in rabbits, each containing different muscle fiber types. We focused on the adductor (ADD) and semitendinosus (ST) as our research subjects and investigated skeletal muscle metabolism at the individual myofibers level using Spatial metabolomics. Additionally, we utilized LC-MS and RNA-Seq to explore the molecular mechanisms underlying the metabolic differences between red and white muscle fibers. Our findings demonstrated that variations in myofiber composition significantly influenced meat color, pH, water content, and drip loss. Spatial metabolomics analysis identified 22 unique red and white muscle fingerprint metabolites, while LC-MS analysis revealed 123 differential metabolites, and these differential metabolites were mainly enriched in the pathways of ABC transporters, Biosynthesis of amino acids, glutathione metabolism, and arginine biosynthesis. To further elucidate the molecular mechanism of differential metabolism in ADD and ST, we identified 2248 differentially expressed genes (DEGs) by RNA-Seq and then combined DEGs with DMs for joint analysis. We found that red muscle exhibited higher levels of metabolites such as L-glutamic acid, glutathione, ascorbate, ornithine, oxidized glutathione, gamma-L-glutamyl-L-cysteine, cysteinylglycine, fumaric acid, gamma-aminobutyric acid. Additionally, related metabolic genes such as MGST1, ODC1, MGST3 and PRDX6 were highly expressed in ST muscle. These metabolites and genes were enriched in the glutathione and nicotinamide pathways, and had significant effects on meat color and drip loss. Moreover, red muscle contained more flavor compounds and nutrients, including adenosine monophosphate (AMP), ornithine, citrulline, taurine, acetyl phosphate, L-glutamic acid metabolites, as well as taurine and hypotaurine metabolites. Our results demonstrate that fresh meat with a higher proportion of red muscle fibers exhibited superior meat quality, enhanced flavor, and higher nutrient content. Furthermore, red muscle contains more antioxidant metabolites that can effectively prevent meat oxidation during the production process.

Protective effects and molecular mechanisms of Litopenaeus vannamei treated with l-arginine/l-lysine against myofibrillar proteins oxidation and quality degradation during freeze-thaw cycles

The storage and processing of Litopenaeus vannamei are often challenged by the freeze-thaw (F-T) cycle phenomenon. This study delved into the influence of pretreatment with l-arginine (Arg) and l-lysine (Lys) on the myofibrillar proteins oxidation and quality of shrimp subjected to F-T cycles. Arg and Lys pretreatment notably improved water-holding capacity (WHC), textural integrity as well as the myofibrillar structure of the shrimps. A lesser reduction in the amounts of immobile and bound water was found in the amino acid-treated groups, and the oxidation of lipids and proteins were both decelerated. Molecular simulation results indicated that Arg and Lys could form hydrogen and salt-bridge bonds with myosin, enhancing the stability of Litopenaeus vannamei. The study concludes that Arg and Lys are effective in alleviating the adverse effects of F-T cycles on the quality of Litopenaeus vannamei, and provides a new solution for the quality maintenance during storage and processing.

Dielectric spectroscopy and TD-NMR investigation for assessing water solid dynamics in normal and wooden breast chicken

Dielectric Spectroscopy (DS) and TimeDomain-Nuclear Magnetic Resonance (TD-NMR) were exploited to investigate water and solid dynamics in chicken's Pectoralis major muscles having macroscopically normal appearance (N) and affected by Wooden Breasts (WB) abnormality. 147 PMM were collected and classified as macroscopically normal (N) (N=74) or Wooden Breast (WB) (N=73) based on their visual appearance and manual palpation. Protons' T2 (transverse relaxation time), and dielectric properties were carried out. The dielectric constant ( [Formula: see text] and the loss factor ( [Formula: see text] of γ relaxation of WB samples was significantly higher than the one of N samples ( [Formula: see text] 59.8 and [Formula: see text] 18.3), while the WB revealed a low relaxation frequency (1.5 E+09) compared to N samples (1.7 E+09). WB showed a higher dielectric constant of relaxation and thus polarizability mainly due to free water, and lower relaxation frequency imputable to a more complex solid structure. This was confirmed by TD-NMR, evidencing a significant increase in the relative intensity of the proton population ascribable to the extra-myofibrillar water (32.9 vs. 21.5%; P<0.001) along with a reduction of the one occupying the intra-myofibrillar spaces (62.0 vs. 75.4%; P<0.001). These outcomes may be ascribed to the re-organization of the skeletal muscle structure associated with the onset and progression of the WB abnormality.

Exploring the effects of ageing on instrumental and sensory characteristics of meat from Lidia breed females: A comparative study of two commercial types

The aim of this study was to assess the influence of ageing on instrumental and sensory qualities in Longissimus thoracis et lumborum (LTL) from heifers (n = 200) and cows (n = 100) of Lidia breed. The animals were slaughtered as heifers (24-48 months) or cull cows (> 48 months). For instrumental analysis, pars Thoracis aged at 7, 14 and 28 days was used; for sensory analysis, pars Lumborum aged at 14 and 28 days was evaluated. Heifers showed redder and yellower meat (P < 0.05) and cows showed slightly higher Water Holding Capacity (WHC): Thawing Loss (TL) = P < 0.05; Drip Loss (DL) = P < 0.01; Pressure Loss (PL) = P < 0.01; Cooking Loss (CL) = P < 0.05. Ageing generated changes in meat colour, with increases in lightness (L*, linear pattern, P < 0.001) and oscillations in a* and b* (quadratic patterns; P < 0.05 and P < 0.001, respectively). Ageing affected TL (increasing, P < 0.001) and PL (decreasing, P < 0.05), and generated a significant improvement in Warner Bratzler Shear Force (WBSF) values (P < 0.001). Commercial type revealed changes in consumer panel ratings for flavour (P < 0.05), juiciness (P < 0.01), tenderness (P < 0.001) and overall acceptability (P < 0.001), with better results in these parameters for cull cows. In contrast to the usual, ageing did not affect the sensory traits. There was no significant interaction between commercial type and ageing time, except for beef flavour, which worsened with ageing (P < 0.05).

Dry-ageing impacts on meat quality, oxidative stability, and release of free amino acids in striploins from dairy crossbred yearling and 2-year-old steers

This study determined the impacts of dry-ageing on meat quality, oxidative stability, and release of free amino acids (FAAs) in striploins from dairy-crossbred yearlings and 2-year-old steers (n = 12 each group) over 21 days of in-bag dry-ageing. Dry-ageing increased weight losses, with higher % drying rates in yearling meat during dry-ageing, likely due to the smaller loin size and lower intramuscular fat content (P < 0.05). Yearling meat showed greater (P < 0.05) decreases in moisture content, but both meats reached similar moisture levels by day 21. pH values increased with dry-ageing with variations at different ageing times. Dry-ageing reduced a*, b*, and chroma while increasing L* and hue angles on day 21 (P < 0.05), likely due to dehydration and lipid oxidation (higher TBARS, P < 0.05) after 14 days, especially in yearling meat. The decreased levels (P < 0.05) of some monounsaturated fatty acids and conjugated linoleic acid cis-9, trans-11 were likely linked with lipid oxidation. Total levels of FAAs and essential amino acids increased significantly, especially within the first 7 days, with distinct patterns between the two meats. Dry-aged yearling meat contained more FAAs associated with sweat taste (e.g., glutamine and glycine) and fewer FAAs associated with bitter taste (e.g., phenylalanine and tyrosine). Carnosine levels varied and significantly increased after 21 days. Dry-ageing demonstrated distinct effects on dehydration, lipid oxidation, and release of FAAs in meat from yearlings compared with 2-year-old steers, which can be tailored to develop high-quality beef products with unique flavours.

TMT-based quantitative proteomics reveals the effects of electromagnetic field and freezing preservation techniques on mutton quality

This study investigated the effects of electromagnetic field preservation (EP) and freezing storage (FS) on the quality of northern Qianbei Ma mutton. Using tandem mass tagging (TMT)-labeled quantitative proteomics and bioinformatics, it was observed that EP more effectively inhibited pH increase and maintained a* and b* values compared to FS. Furthermore, the EP group was able to better maintain the water-holding capacity and tenderness of the mutton under prolonged storage. Proteomics analysis identified 397 differentially expressed proteins (DEPs) between the two storage methods at the same storage duration. GO and KEGG enrichment analyses indicated that proteins such as A0A452DSW4, A0A452E8M7, and D3JYV6 were involved in energy metabolism and redox processes, while A0A452EJ66, A0A452DSW4, and A0A452FJE8 played significant roles in protein binding. Overall, EP technology demonstrated superior benefits for maintaining mutton quality, suggesting a novel approach for mutton preservation.

Extracellular Vesicles and PlantCrystals for Improved Bioavailability of Curcumin as a BCS Class IV Drug

The limited water solubility of active compounds remains a significant challenge for efficient dermal drug delivery, particularly for BCS class IV drugs such as curcumin. This study aimed to enhance curcumin's dermal penetration using two strategies: extracellular vesicles (EVs) and plantCrystals derived from soybeans. EVs were isolated using classical methods. However, plantCrystals containing extracellular vesicles (PCEVs) were formed during the preparation of plantCrystals through bead milling. Curcumin was either added after PCEVs were formed, resulting in curcumin-added PCEVs, or added to the soybean dispersion before bead milling, forming curcumin-loaded PCEVs. The formulations were characterized for their physicochemical properties and assessed for dermal penetration efficacy using quantitative dermatokinetic and semi-quantitative ex vivo porcine ear models. The results indicated that curcumin-loaded PCEVs achieved higher penetration efficacy compared to curcumin-added PCEVs and curcumin-loaded EVs, with approximately 1.5-fold and 2.7-fold increases in penetration efficacy, respectively. Additionally, curcumin-loaded PCEVs showed superior penetration depth, while curcumin from the curcumin-loaded EVs remained in the stratum corneum. These findings suggest that the plantCrystals strategy via bead milling offers a more effective approach than the classical EVs strategy for improving the topical delivery of class IV drugs like curcumin.

Effects of Gynura procumbens extract supplementation on growth performance, carcass traits, antioxidant capacity, immunity and meat quality of meat ducks

Introduction

Gynura procumbens (Lour.) Merr is a common traditional Chinese medicine with anti-tumor, anti-inflammatory and antioxidant activities. However, no related studies reported the potential application effect of Gynura procumbens on meat ducks. The study aims to investigate the potential effects of Gynura procumbens extract (GPE) supplementation on growth performance, carcass traits, antioxidant capacity, immunity and meat quality.

Methods

A total of 480 21-day-old female healthy ducks were randomly allocated to four treatments, each treatment containing six replicates with 20 ducks per replicate. The groups received a corn-soybean basal diet supplemented with 0 mg/kg GPE (CON), 200 mg/kg GPE (GPE200), 400 mg/kg GPE (GPE400), and 600 mg/kg GPE (GPE600), respectively. The entire experiment lasted for 7 weeks.

Results

The results showed that dietary supplementation with 600 mg/kg GPE significantly reduced the contents of serum urea nitrogen, triglyceride (TG) and total cholesterol (TC). GPE (200, 400, and 600 mg/kg) supplementation effectively reduced the contents of IL-2 and MDA. The levels of immunoglobulin M (IgM) as well as total antioxidative capacity (T-AOC) in GPE600 group dramatically elevated in comparison with the control group. Dietary GPE supplementation considerably increased the moisture content of the breast muscle. Furthermore, dietary supplementation with GPE markedly decreased the water loss rate and shear force.

Discussion

With the ban of antibiotics in poultry production, traditional Chinese medicines have been widely used in livestock and poultry production due to their high efficiency and low toxicity. Gynura procumbens extract GPE as a natural plant origin contains a series of biologically active components, including flavonoids, polyphenols, saponin, tannin and terpenoid. This study indicated that dietary supplementation with GPE can increase serum total antioxidant capacity, regulate immune function and improve meat quality to some extent in meat ducks. The recommended optimal GPE level in the diet of meat ducks is 600 mg/kg according to the results in this study.

Muscle-Specific Effects of Genotype, Animal Age, and Wet Aging Duration on Beef Color, Tenderness, and Sensory Characteristics

This study investigated the effects of genotype, animal age, muscle type, and aging duration on meat quality characteristics of Psoas major (PM), Longissimus thoracis (LT), Longissimus lumborum (LL), and Gluteus Medius (GM) muscles. The PM, LT, LL, and GM muscles were sourced from a total of 32 bulls, consisting of 16 humped (Bos indicus) and 16 humpless (Bos indicus × Bos taurus) bulls aged 21 ± 2 and 30 ± 3 months. The muscles underwent aging durations of 0, 7, and 14 days. Meat pH, color, drip loss, cooking loss, instrumental shear force, lipid oxidation (thiobarbituric acid reactive substances/TBARS), and sensory analysis were performed. Our results indicated that humped bulls had superior color, while humpless bulls exhibited better sensory characteristics. The 30 ± 3 months of age bulls showed improved color and sensory characteristics with higher TBARs values than the 21 ± 2 months of age bulls. The color, tenderness, and sensory characteristics improved in PM and LT at 7 days, whereas in LL and GM they improved at 14 days. PM showed better tenderness and overall acceptability among different muscles, while LL showed better color and oxidative stability. This study suggested the necessity of muscle-specific aging strategies to enhance the meat quality characteristics of humped and humpless bulls. Further research could explore additional aging durations and other muscle types to better understand their impact on meat quality characteristics.

Can the Suspension Method (Tenderstretch vs. Achilles Tendon) Enhance Horsemeat Quality?

This study investigated whether the suspension method (tenderstretch, TS or Achilles tendon, AT) can improve the quality of horsemeat by analyzing longissimus dorsi (LD) and semitendinosus (ST) muscles. A total of 25 horse carcasses were considered experimental units and split longitudinally, with one half suspended using the TS method and the other half using the AT method, which enabled a direct comparison within the carcass. After 7 days of aging under commercial processing conditions, the LD and ST muscles were analyzed for pH, color (L*, a*, b*), water-holding capacity (drip loss, thawing loss, cooking loss), tenderness (Warner-Bratzler shear force), and sarcomere length. Statistical analysis was performed using the MIXED procedure in SAS, with Bonferroni correction applied for post hoc comparisons. Significant differences were found between the muscles: LD had higher tenderness (39.28 N vs. 49.77 N, p = 0.0011), lower cooking loss (23.56% vs. 27.04%, p = 0.0002), and higher thawing loss (12.38% vs. 9.72%, p = 0.0021) compared to ST muscle, which had a lighter color (L* = 41.90 vs. 37.73, p < 0.0001) and longer sarcomeres (2.22 μm vs. 1.74 μm, p < 0.0001). While the TS suspension method significantly increased sarcomere length (2.05 μm vs. 1.92 μm, p = 0.0020), it did not lead to significant improvements in other quality attributes such as pH, water-holding capacity, or tenderness. The results indicate that although the TS method affects muscle structure by elongating sarcomeres (with an average difference of 0.13 μm), it does not significantly improve the overall quality of the horsemeat compared to the AT method after 7 days of aging. A combination of factors beyond suspension methods, such as optimizing aging periods or considering additional processing techniques, may therefore be required to improve horsemeat quality. This study provides insights into the specific attributes of LD and ST muscles and their response to suspension methods and contributes to a better understanding of optimizing horsemeat quality for commercial purposes.

Addition of Carrot Pomace to Enhance the Physical, Sensory, and Functional Properties of Beef Patties

The global challenge of food waste necessitates innovative solutions, such as incorporating carrot pomace, a nutrient-rich by-product of carrot juice production, into beef patties to enhance their nutritional and functional properties. This study evaluated beef patties with carrot pomace added at 0%, 1.0%, 3.0%, and 4.2%, analyzing the proximate composition, pH, color, cooking yield, water-holding capacity (WHC), texture, and sensory attributes. Adding 3.0% and 4.2% pomace significantly reduced the moisture content by 5.5% and 3.3%, respectively, and decreased redness by 40% in the 4.2% patties. The cooking yield increased by 13.9% and 22.8%, and WHC improved by 8.5% and 15.7%, respectively, with these additions. The textural properties showed substantial reductions in hardness, cohesiveness, gumminess, and chewiness, particularly at 4.2%. The sensory evaluation indicated no significant differences in appearance, aroma, taste, or overall liking for patties with up to 3% pomace. In comparison, patties with 4.2% pomace received lower scores for overall liking and firmness. These findings suggest that incorporating up to 3% carrot pomace in beef patties enhances their functional properties and dietary fiber content without compromising the sensory quality. This offers a sustainable and practical approach to food waste valorization.

Consumer eating quality and physicochemical traits of pork Longissimus and Semimembranosus differed between genetic lines

Pork eating quality is affected by various factors. In this study, Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM) muscles from seven genetic lines (PM-LR - Pure maternal, Landrace-type; PM-LW - Pure maternal, Large White-type; PM-D - Pure maternal, Duroc-type; PT-D - Pure terminal, Duroc-type; PT-LW - Pure terminal, Large White-type; PT-LR - Pure Terminal, Landrace-type; Comp-P × LW × D - Composite Terminal - Pietran × Large white × Duroc) were analyzed for pH, intramuscular fat (IMF) content, and collagen content and solubility. A consumer sensory test using check-all-that-apply (CATA) and biometric approaches was also conducted. The results showed that the IMF content of line PM-D was the highest (P = 0.004), while line PT-LW received the highest score in tenderness, liking of flavor, purchase intent, and quality grading (P < 0.05). Line PM-LR and PT-LR showed the lowest IMF content and were least preferred by consumers. Compared to LTL, SM showed higher pH, collagen solubility, and sensory scores in tenderness, juiciness, liking of flavor, and overall liking (P < 0.05). Different muscles and lines were associated with different CATA terms but not with differences in consumer emotional responses. pH positively influenced tenderness, juiciness, and overall liking (P < 0.05), but IMF and collagen had little effect. The flavor was the most important sensory attribute contributing to overall liking, followed by tenderness. Genetic line and muscle affected pork chemical properties and eating quality. The findings are important for the Australian pork industry to improve the eating quality of their products.

Growth Performance, Carcass Quality, and Lipid Metabolism in Krškopolje Pigs and Modern Hybrid Pigs: Comparison of Genotypes and Evaluation of Dietary Protein Reduction

This study compared the performance, meat quality and adipose tissue characteristics of Krškopolje pigs and modern hybrid pigs under identical rearing conditions, besides examining the effects of dietary protein reduction in both genotypes. A total of 29 pigs (14 Krškopolje and 15 hybrids) were assigned to litter into two dietary groups (high and low protein). The low-protein diet for hybrid pigs corresponded to the high-protein diet for Krškopolje pigs. All diets were iso-energetic. Dietary protein reduction decreased growth rate and muscle development in modern hybrids but had no significant impact on performance, quality or metabolic traits in Krškopolje pigs. Genotype differences revealed that Krškopolje pigs had lower growth rates, less lean and more fat deposition, as reflected in thicker subcutaneous and higher intramuscular fat compared to modern hybrids. Krškopolje pigs also exhibited higher myoglobin concentration and fatty acid saturation. Lipogenic enzyme activity and histo-morphological traits behaved in a tissue-specific manner but still indicated a greater lipogenic potential in Krškopolje pigs. This study provides valuable insights into breed-specific responses to dietary changes and highlights the unique characteristics of Krškopolje pigs.

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.

Natural plant polyphenols contribute to the ecological and healthy swine production

The absence of trace amounts of natural bioactive compounds with important biological activities in traditional dietary models for global farm animals, coupled with an incomplete theoretical system for animal nutrition, has led to unbalanced and inadequate animal nutrition. This deficiency has adversely impacted animal health and the ecological environment, presenting formidable challenges to the advancement of the swine breeding industry in various countries around the world toward high-quality development. Recently, due to the ban of antibiotics for growth promotion in swine diets, botanical active compounds have been extensively investigated as feed additives. Polyphenols represent a broad group of plant secondary metabolites. They are natural, non-toxic, pollution-free, and highly reproducible compounds that have a wide range of physiological functions, such as antioxidant, anti-inflammatory, immunomodulatory, antiviral, antibacterial, and metabolic activities. Accordingly, polyphenols have been widely studied and used as feed additives in swine production. This review summarizes the structural characteristics, classification, current application situation, general properties of polyphenols, and the latest research advances on their use in swine production. Additionally, the research and application bottlenecks and future development of plant polyphenols in the animal feed industry are reviewed and prospected. This review aims to stimulate the in-depth study of natural plant polyphenols and the research and development of related products in order to promote the green, healthy, and high-quality development of swine production, while also providing ideas for the innovation and development in the theoretical system of animal nutrition.

Effect of water migration on changes of quality and volatile compounds in frozen Penaeus monodon

The purpose of this study was to clarify effects of water changes on the quality and volatile compounds of Penaeus monodon during frozen storage. The content of immobilized water decreased significantly while the bound water and free water increased significantly. Total sulfhydryl content, and Ca2+-ATPase activity decreased significantly to 68.31 μmol/g and 0.127 U/mg, meantime, carbonyl content and MFI value increased significantly to 2.04 μmol/g prot and 55.10. Total of 50 volatile compounds were identified. Nonanal (M & D), 2-nonanone and octanal were only detected in fresh samples, while 3-hydroxy-2-butanone and 1-hydroxy-2-propanone were only found in the samples after 20 days of storage. Correlation analysis revealed that 6 of the volatile compounds were associated with the change of free water. Total of 28 and 17 volatile compounds showed significant correlations with the immobilized water and bound water, respectively. Four volatile compounds have the potential to be used as the flavor marker.

Impact of a 15% spirulina (Limnospira platensis) dietary inclusion on productive performance and meat traits in naked neck and fully feathered slow-growing broiler strains

Global population is rising, leading to higher demand for meat and concerns on environmental and economic impacts of conventional feedstuffs that corn and soybean meal have. Recently there has been a shift towards more sustainable feedstuffs such as Spirulina (Limnospira platensis) due to its nutritional value and ability to be produced locally. Consumer awareness prompts shifts towards free range poultry production but presents environmental challenges due to climate change. The naked neck (Na) gene, which reduces feather coverage, and enhances growth under adverse conditions offers a possible solution for improved welfare and efficiency. This study aims to investigate the impact of a diet with 15% Spirulina inclusion on growth performance, carcass traits, and meat quality of two slow-growth broiler strains: naked neck (NN) and fully feathered (FF). Forty, 1-day-old male broilers, 20 per strain, were randomly assigned to either a control or a diet containing 15% Spirulina, housed individually in cages and fed ad libitum for 84 d. Growth, carcass, and meat traits were evaluated. Results indicated that animals fed a control diet generally outperformed those fed a Spirulina diet in final body weight (BW), average daily gain (ADG), feed intake (FI), and feed conversion rate (FCR) (P < 0.001). Additionally, Spirulina incorporation led to an increase in the length of the gastrointestinal tract and digesta viscosity in the duodenum plus jejunum (P < 0.05). Although there were no significant differences in breast muscle yield between dietary groups, SP-fed broilers had higher yellowness (*b) values in meat (P < 0.05). Except for the decrease in water holding capacity (WHC) observed in the NN group animals (P < 0.05), there were no significant differences between the strains for the remaining meat quality traits (P > 0.05). The 15% Spirulina inclusion increased the concentrations of n-3 polyunsaturated fatty acids (PUFA) (P < 0.0001) in breast meat and decreased (P < 0.0001) nutritional ratios. Overall, under thermoneutral conditions, animals from the NN strain showed negative effects on growth parameters. Spirulina inclusion improved certain aspects of breast meat quality, particularly fatty acid profiles.

Sequential window acquisition of all theoretical mass spectra (SWATH-MS) as an emerging proteomics approach for the discovery of dark-cutting beef biomarkers

Recent advances in "omics" technologies have enabled the identification of new beef quality biomarkers and have also allowed for the early detection of quality defects such as dark-cutting beef, also known as DFD (dark, firm, and dry) beef. However, most of the studies conducted were carried out on a small number of animals and mostly applied gel-based proteomics. The present study proposes for the first time a Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) proteomics approach to characterize and comprehensively quantify the post-mortem muscle proteome of DFD (pH24 ≥ 6.2) and CONTROL (5.4 ≤ pH24 ≤ 5.6) beef samples within the largest database of DFD/CONTROL beef samples to date (26 pairs of the Longissimus thoracis muscle samples of young bulls from Asturiana de los Valles breed, n = 52). The pairwise comparison yielded 35 proteins that significantly differed in their abundances between the DFD and CONTROL samples. Chemometrics methods using both PLS-DA and OPLS-DA revealed 31 and 36 proteins with VIP > 2.0, respectively. The combination of different statistical methods these being Volcano plot, PLS-DA and OPLS-DA allowed us to propose 16 proteins as good candidate biomarkers of DFD beef. These proteins are associated with interconnected biochemical pathways related to energy metabolism (DHRS7B and CYB5R3), binding and signaling (RABGGTA, MIA3, BPIFA2B, CAP2, APOBEC2, UBE2V1, KIR2DL1), muscle contraction, structure and associated proteins (DMD, PFN2), proteolysis, hydrolases, and activity regulation (AGT, C4A, GLB1, CAND2), and calcium homeostasis (ANXA6). These results evidenced the potential of SWATH-MS and chemometrics to accurately identify novel biomarkers for meat quality defects, providing a deeper understanding of the molecular mechanisms underlying dark-cutting beef condition.

Chitosan coatings containing thyme essential oil enhance the quality of snakehead (Channa striata) during chilled storage verified by metabolomics approaches

In the present study, we investigated the preservative effects of chitosan (CS) coatings, with and without thyme essential oil (TEO), combined with vacuum impregnation (VI) on maintaining the quality of snakehead fillets during chilled storage. The results showed that the VI treatment significantly inhibited drip loss, discoloration, microbial proliferation, and the accumulation of biogenic amines (BAs) in the sneakhead fillets. Compared to the control, the fillets treated with VI of 1% (w/w) CS and 1.5% (w/w) TEO (i.e., CSTEO) showed significant reductions in both psychrophiles and mesophiles, with a 2.66 log CFU/g decrease in total viable count (TVC) on day 3 and a 1.89 log CFU/g decline in TVC on day 9, respectively. In addition, the content of histamine and putrescine in the CSTEO groups was maintained at ∼1.14 and 3.23 mg/kg during the 12-day chilled storage, respectively. A total of 100 chemical compounds were tentatively identified using untargeted metabolomics approaches. The multivariate analysis further revealed that the combination of VI and CSTEO maintained fish quality mainly through preventing lipid oxidation and protein degradation. Overall, the VI-CSTEO treatment effectively maintained the fish quality during storage at 4°C, with minimum microbial proliferation and accumulation of BAs. PRACTICAL APPLICATION: The preservative effect of chitosan coatings containing thyme essential oil combined with vacuum impregnation on snakehead quality during the 12-day chilled storage was verified, and the underlying mechanisms were deciphered through integrated metabolomics approaches. Our study could provide a promising strategy for the preservation of aquatic products.

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 (r s  = -0.30) and the belly slices (r s  = -0.27 to -0.32). The pH of the SC muscle showed a correlation with the CLs of the butt slices (r s  = -0.45) and the belly slices of the 6th and 11th thoracic vertebrae (r s  = -0.28 to -0.33). Additionally, the correlations (r s  = 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.

Evaluation of the Physicochemical Attributes of Beef, Chicken, and Pork Muscles Injected with Microbial Proteases for Designing Senior-Friendly Processed Meat Products

In developed countries, the growing elderly population has increased the demand for senior-friendly processed meat products. This study investigated the effects of four commercial microbial proteases (Alcalase, Flavourzyme, Neutrase, and Protamex) on the general physicochemical attributes of beef top round, chicken breast, and pork loin, which are lean muscle cuts suitable for developing senior-friendly meat products. Muscle samples were injected with microbial protease solutions (0.7% and 1.2% (w/w)), cooked, and used for analysis. The microbial protease injection significantly reduced the hardness of cooked muscles. Despite the evident degradation of the myosin heavy chain in Alcalase treatment, the lowest hardness values were observed in Protamex-treated samples, suggesting that myosin degradation alone does not fully account for tenderness improvement. Unfortunately, microbial protease treatments increased cooking loss in beef and chicken muscles (p < 0.05). The surface color characteristics, including redness and yellowness, remained unaffected by the enzymatic treatments, supporting the practical use of these proteases for meat tenderization without inducing color defects. While microbial proteases demonstrate potential for improving meat tenderness, future research should focus on mitigating cooking loss and ensuring desirable taste and flavor for the commercial production of senior-friendly processed meat products using the microbial proteases.

Efficient Inhibition of Ice Recrystallization During Frozen Storage: Based on the Diffusional Suppression Effect of Silk Fibroin

Effectively controlling ice recrystallization (IR) during the frozen storage of food remains highly challenging. Inspired by the structural characteristics of antifreeze proteins in nature, silk fibroin (SF) derived from silk fibers has been developed. Through dual validation using the "splat" assay and "sucrose sandwich" assay, the IR inhibition activity of SF at various concentrations was confirmed, revealing that its regular alternating hydrophilic/hydrophobic domains endow SF with the potential to inhibit the axial growth of single ice crystal and significantly reduce the average maximum crystal size by approximately 67%. Additionally, the quality stability of frozen muscle foods treated with SF was comprehensively evaluated. In stark contrast to traditional commercial antifreeze agents (4% sucrose and 4% sorbitol), prepared steaks with the addition of 2% SF maintained rich juiciness and excellent color acceptability over a three-month frozen storage period. Thus, SF holds promise as a potential protective agent for frozen muscle foods, enhancing their quality during storage.

The carcass characteristics and quality of meat from lambs grazing perennial wheat with different companion legumes (clover, serradella, lucerne) or a mineral supplement

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality.

Optimizing tenderness of M. Semitendinosus steak for elderly people with the combination of ficin and sous-vide cooking

This study aimed to evaluate the sous-vide cooking and ficin treatment effects on the tenderness of beef steak and optimize it for the elderly using response surface methodology (RSM). The M. semitendinosus (ST) from Chikso cattle was shaped into 5 × 5 × 2.54 cm pieces. Ficin solution was injected into the ST steak at 10% of the meat weight, and sous-vide cooked in a water bath at 65 °C for 6 or 12 h. As ficin concentration increased, L*- and a*-value, shear force, and hardness decreased, while soluble peptides increased (P < 0.05). As cooking time increased, cooking loss and collagen solubility of the steak increased (P < 0.05). An interaction effect between ficin and sous-vide cooking was found in L*- and a*-value, shear force, hardness, and soluble peptides (P < 0.05). A model to optimize the hardness for elderly people was established (R2 = 0.7991). Optimization conditions by RSM were 0.86 U/L with 8.87 h (23 N/cm3) for tooth intake (grade 1), 16.31 U/L with 13.24 h (3 N/cm3) for gums intake (grade 2), according to KS H 4897 and Universal Design Foods concept for the elderly. These optimized conditions enable the production of customized products tailored to the oral conditions of elderly people.