Effect of mitochondrial calcium homeostasis-mediated endogenous enzyme activation on tenderness of beef muscle based on MCU modulators

The mitochondrial calcium uniporter (MCU) occupies a noteworthy position in the regulation of mitochondrial calcium uptake. This study investigated the effects of MCU modulator-mediated mitochondrial calcium on mitochondrial dysfunction, oxidative stress, endogenous enzyme activities, and tenderness during postmortem aging. Spermine, as an activator of MCU, resulted in an increase in mitochondrial calcium levels, not only disrupting mitochondrial morphology but also triggering mitochondrial oxidative stress and downregulation of antioxidant factors. Additionally, the spermine group underwent later activation of calpain and earlier activation of caspases, as well as the myofibril fragmentation index was initially lower and then higher compared with control group, indicating that endogenous enzymes played an indispensable role in different aging periods. Interestingly, the results of the Ru360 (an inhibitor of MCU) group were opposite to those aforementioned findings. Our data provide a novel perspective on the regulatory mechanism of mitochondrial calcium homeostasis mediated by MCU on tenderness.

New perspective for Calpain-Mediated regulation of meat Quality: Unveiling the impact on mitochondrial pathway apoptosis in post-mortem

While calpain's role in myofibrillar protein degradation is well-established, its impact on post-mortem apoptosis remains fully elucidated. This study aimed to examine how calpain influences the mitochondrial apoptotic pathway in post-mortem muscle cells and assess its potential impact on chicken tenderness. The findings indicate that the calpain inhibitor treatment could decelerate the rate of lysosome destruction in post-mortem chicken, which is a crucial factor in delaying the mitochondrial apoptotic pathway. Subsequently, this inhibition enhanced the mitochondrial membrane's stability and suppressed the apoptosis-inducing factor Cyt c release into the sarcoplasm. The Western blot results in a greater myofibrillar protein degradation degree in the caspase inhibitor samples compared to the calpain inhibitor samples. Interestingly, the two groups had no significant difference in shear force. Based on these reasons, a novel perspective was introduced in this paper: Calpain could affect the change in meat tenderness by regulating mitochondrial apoptosis in the post-mortem period.

Myofibrillar proteins' intermolecular interaction weakening and degradation: Are they mainly responsible for the tenderization of meat containing l-arginine, l-lysine, or/and NaCl?

This study explored the effects of l-arginine, l-lysine, and NaCl alone and in combination on the tenderness of porcine meat. Arg, Lys, and NaCl alone improved the tenderness, decreased the cooking loss, and increased the myofibrillar fragmentation index (MFI) of porcine meat; Both Arg and Lys cooperated with NaCl to better achieve this effect. Furthermore, Arg/Lys collaborated with NaCl to increase muscle fiber swelling and moisture content of the meat and promoted the extraction of main myofibrillar proteins. FT-IR revealed that Arg, Lys, or NaCl alone or in combination caused changes in protein-water interactions. Western blotting revealed varying degrees of meat protein degradation in all cases, but the results did not well coincide with those of shear force and the MFI. Therefore, the weakening of intermolecular forces between myofibrillar proteins was considered the main reason for meat tenderization under the present study conditions.

Freezing/thawing as an accelerating process of wet- and dry-aged Nellore beef

This study aimed to evaluate the use of freezing/thawing as a way of accelerating the aging processes of beef from Nellore animals. Non-frozen (NF) or freezing/thawing (FT) strip loins were aged (for 14 and 28 days) using two systems: bone-in dry-aging (DA); boneless wet-aging (WA). FT-treated samples had greater weight losses (P < 0.05) during aging than NF-treated samples, especially using the DA process. However, the weight loss of the FT 14-days DA beef samples was comparable to that of NF 28-days DA. FT beef had lower fragmentation index and shear force values (P < 0.05), as well as its maximum sensorial tenderness was achieved earlier (P < 0.05) than the NF counterpart. With 28 days of aging, DA beef showed higher (P < 0.05) tenderness and juiciness scores and lower lightness values than WA beef. The FT process decreased the reducing capacity of meat samples, generating more metmyoglobin and lower amounts of chroma than NF. The expected volatile profile of DA beef was achieved faster in FT-treated samples, but the freezing treatments did not compromise the microbial count for either aging system. Our findings indicate that accelerated DA by the FT process could improve the palatability of Nellore beef, allowing the desired tenderness and flavor profile to be achieved in a shorter time, without increasing costs with weight losses or adversely affecting physicochemical, chemical, and microbial characteristics.

Effect of accelerated aging on shelf-stability, product loss, sensory and biochemical characteristics in 2 lower quality beef cuts

The aim of this study was to determine the impact of accelerated aging (AA) on shelf stability, product loss, sensory and biochemical characteristics of 2 lower quality beef cuts. Triceps brachii (TB) and semimembranosus (SM) were collected and fabricated from 10 USDA Choice beef carcasses and assigned to 1 of 6 treatments: 3 d cooler aged (control), 21 d cooler aged, AA 49 °C for 2 h, AA 49 °C for 3 h, AA 54 °C for 2 h, and AA 54 °C for 3 h. The results showed that AA can decrease APC counts on steak surface and in purge and redness, but increase lightness and product loss of the steaks (P < 0.01). Lower shear force was also found for AA steaks compared to those from the control (P < 0.01), with the AA 54 °C treatments being comparable to 21 d cooler aging. However, the trained sensory panel determined AA steaks were less juicy and flavorful than those from the control and 21 d cooler aged samples (P < 0.05). There was no off-flavor detected in AA steaks though lipid oxidation was higher in AA samples than those in the control steaks (P < 0.01). The AA treatments stimulated cathepsin activity (P < 0.05), which may have enhanced the solubilization of stromal proteins and led to a different troponin-T degradation pattern compared to those from the 21 d aged samples (P < 0.01). Although AA is an economical and time-efficient method to increase tenderness of lower-quality beef cuts, further research is needed to determine strategies to mitigate the decrease in juiciness from AA treatments.

Mechanism underlying the tenderness evolution of stir-fried pork slices with heating rate revealed by infrared thermal imaging assistance

This study aimed to explore the mechanism of cooking intensity on the tenderness of stir-fried pork slices from the perspective of the changes in temperature distribution. Infrared thermal imaging was used to monitor the distribution of temperature. Results showed that the high-level heat (HH) treatment could improve tenderness. When the center temperature increased to 100 °C, the shear force of samples from the low-level heat (LH) group increased by around 3-fold, and HH reduced this upward trend. This result was mainly attributed to the shorter heating time undergone by the HH-treated samples compared to the LH treatment, which resulted in less structural shrinkage and faster passing through the protein denaturation interval of the samples. These changes alleviated temperature fluctuations caused by water loss. This explanation could be confirmed by the results of T2 relaxation time and Fourier transform-infrared spectroscopy (FT-IR). However, the LH treatment caused a slower rise in oil temperature due to more moisture migration, which required the samples to undergo longer thermal denaturation, leading to a deterioration in tenderness. Moreover, histological analysis revealed that the greater integrity of endomysium in the HH group inhibited water loss and oil absorption, which contributed to obtain low-fat meat products with higher tenderness. This study provides support for the industrialization of traditional pork cuisines using oil as the heating medium.

Investigating the impact of sous vide cooking on the eating quality of spent buffalo (BUBALUS BUBALIS) meat

This study describes the impact of sous vide cooking at different temperatures and time intervals on the eating quality, specifically tenderness of two muscles, bicep femoris (BF) and semitendinosus (ST) from spent buffalo (Bubalus bubalis). Spent buffalo refers to water buffalo that are no longer considered productive following a sixth lactation cycle. Steaks from each muscle were obtained and cooked at three combinations of time and temperature, namely 55 °C-8H, 65 °C-5H, and 95 °C-45 M, respectively. Warner-Bratzler Shear Force (WBSF), cooking loss, cooking yield, color, water activity (aw), total water content (TWC), total collagen content (TCC), heat soluble collagen (HSC), myofibrillar fragmentation index (MFI), and sensory evaluation were measured. The collagen solubilization results showed that temperature and time interacted (P ≤ 0.05), reducing the toughness of the muscles. The tenderization achieved through sous vide cooking was mainly attributed to the thermal denaturation of proteins at the typically lower temperatures and extended time used, weakening of connective tissue through collagen solubilization, and water retention. More cooking loss (P ≤ 0.05) was observed at high temperature treatment of 95 °C-45 M. Meat color, TWC, MFI, and overall acceptability exhibited differences among treatments (P ≤ 0.05). An extended heat interval at lower temperatures caused initial denaturation of myofibrillar proteins, then solubilization of connective tissue proteins. Cooking treatment 55 °C-8H (P ≤ 0.05) reduced the WBSF in both muscles; however, the ST appeared more tender than BF.

Impact of cooking temperature on pork longissimus, and muscle fibre type, on quality traits and protein denaturation of four pork muscles

Variations in pork quality impact consumer acceptance, and fibre type differences between muscles contribute to this variation. The aim was to investigate the influence of variations in muscle fibre types and protein denaturation peaks across four pork muscles and the influence of ageing and cooking temperature on longissimus quality traits. The longissimus, masseter, cutaneous trunci, and psoas major from 13 carcases were removed 1-day postmortem and subjected to 0- or 14-days ageing (d0, d14). Quality traits, protein denaturation peak temperature (DSC), fibre diameter and fibre type proportions were measured. Cook loss for longissimus was similar on d0 and d14, but was higher on d14 for masseter, cutaneous trunci, and psoas major. Warner-Bratzler shear force was highest, and ultimate pH was lowest, for longissimus, and similar among cutaneous trunci, masseter, and psoas major. Masseter had lowest L* and highest a* and longissimus and cutaneous trunci had highest L* and lowest a*. The DSC temperature peaks for longissimus occurred at lower temperatures relative to the other muscles. Fibre diameter was largest for type-IIb fibres relative to type-IIa and type-I. Longissimus and cutaneous trunci had predominantly type-IIb glycolytic (71%, 51% respectively), masseter had predominantly type-IIa intermediate (50%) and psoas major had predominantly type-I oxidative (48%) fibres. The glycolytic longissimus had the lowest DSC temperature peaks and the lowest quality meat. Masseter had the highest proportion of type-I fibres but was generally similar in quality traits to psoas major, and also similar to cutaneous trunci which had more glycolytic fibres than masseter.

Reproductive Strategies and Romantic Love in Early Modern Europe

In Western Europe, the Early Modern Period is characterized by the rise of tenderness in romantic relationships and the emergence of companionate marriage. Despite a long research tradition, the origins of these social changes remain elusive. In this paper, we build on recent advances in behavioral sciences, showing that romantic emotional investment, which is more culturally variable than sexual attraction, enhances the cohesion of long-term relationships and increases investment in children. Importantly, this long-term strategy is considered especially advantageous when living standards are high. Here, we investigate the relationship between living standards, the emotional components of love expressed in fiction work, and behavioral outcomes related to pair bonding, such as nuptial and fertility rates. We developed natural language processing measures of "emotional investment" (tenderness) and "attraction" (passion) and computed romantic love in English plays (N = 847) as a ratio between the two. We found that living standards generally predicted and temporally preceded variations of romantic love in the Early Modern Period. Furthermore, romantic love preceded an increase in nuptial rates and a decrease in births per marriage. This suggests that increasing living standards in the Early Modern Period may have contributed to the emergence of modern romantic culture.

Effect of packaging thickness and muscle type on ultrasound-assisted beef quality

High-intensity ultrasound (HIU) can modify muscle structure, leading to improvements in tenderness. However, factors such as packing type and muscle complexity may attenuate the acoustic cavitation. In this research, the effect of packing thickness (40.6-70 μm) on the quality of bovine Gluteus medius and Biceps femoris treated with HIU (37 kHz, 90 W/cm2, 40 min) was evaluated. The hardness of G. medius decreased significantly as the thickness of the packing bag decreased. The wide interfibrillar and intermyofibrillar spaces corroborated the tenderizing effect. These effects are related to damage of cell structure and changes in the collagen content (3.37 ± 0.1 µg/mL). In addition, the HIU decrease the variability in the water holding capacity of the muscle produced by the use of low thickness bags during storage. The trained sensory panel described the sonicated samples in 50.8 μm bags as less hard and juicier. Contrarily, in B. femoris no significant effects were reported in the variables evaluated. B. femoris is a white muscle, with a high amount of collagen (3.59 ± 0.1 µg/mL) and little intramuscular fat. Consequently, the effect of the HIU on muscle quality is associated with the composition of the muscle fibers and the thickness of the packing bag. HIU application is recommended to improve the quality of leg muscles whenever low-thickness bags (50.8 μm or less) are used.

Effects of ultrasound-assisted cooking on the physicochemical properties and microstructure of pork meatballs

This research aims to investigate the effect of different ultrasonic powers cooking on the quality of pork meatballs. Pork meatballs treated with ultrasound-assisted cooking at 450 W had the most uniform and smooth structures displayed by scanning electron microscopy. Furthermore, with increasing ultrasonic powers, the water retention capacity of pork meatballs first increased and then decreased, compared with the non-ultrasound group, when the ultrasonic power was 450 W, the cooking yield of pork meatballs increased from 82.55% to 92.87%, and the centrifugal loss decreased from 25.35% to 11.52%. Additionally, ultrasound-assisted cooking had a positive effect on the moisture migration, tenderness, and sensory property of pork meatballs, and 450 W sample exhibited the highest overall acceptability score (P < 0.05). In conclusion, the physicochemical properties and microstructure of pork meatballs could be improved by appropriate ultrasonic power, and ultrasonic technology was considered as an effective processing method for improving the quality of meat products.

Genetic parameter estimates for sensory and meat quality traits measured at 3 and 29 days of aging of beef from Canadian crossbred cattle

Genetic parameters were estimated for objective and subjective traits assessed after 3 and 29 days aging in meat samples of 1154 commercial beef cattle. Meat attributes [Warner-Bratzler shear force (WBSF), intramuscular fat (IMF), and pH] and sensory traits [flavor intensity (FI), off-flavor (OF), connective tissue (CT), overall tenderness (OT), sustained juiciness (SJ), and overall palatability (OP)] were available. The animal mixed model used included additive genetic and residual effects as random effects, contemporary group as fixed effect and genomic breed composition and slaughter age as covariates. Genetic parameters were estimated using airemlf90 software and single-step genomic BLUP. Heritability estimates for OT (3 and 29 d), OP (3 d) and OF (29 d) were of moderate magnitude ranging from 0.18 ± 0.07 to 0.31 ± 0.07. Heritabilities were negligible or of low magnitude for all other sensory traits with values ranging from 0.03 ± 0.05 to 0.14 ± 0.07. Among objectively measured traits, the estimate of heritability for meat pH was moderate at day 3 (0.20 ± 0.08) and negligible at 29 (0.00 ± 0.05). For IMF and WBSF the heritability estimates were 0.43 ± 0.09 and 0.54 ± 0.09, and 0.22 ± 0.07 and 0.19 ± 0.07 for day 3 and 29, respectively. Genetic correlations between days for each sensory trait tended to be of high and positive magnitude ranging from 0.54 ± 0.60 to 0.99 ± 0.28. Genetic and phenotypic correlations of subjectively assessed traits were consistent in direction and magnitude with WBSF (negative) and IMF (positive) suggesting that genetic selection based on objectively measured traits can be used for meat quality improvement and to increase consumer satisfaction. In addition, selection can be implemented using sensory traits collected after 3 days of aging.

Effects of different protein phosphorylation levels on the tenderness of different ultimate pH beef

This study investigated the relationship between tenderness and protein phosphorylation levels of normal ultimate pH (pHu, 5.4-5.8, NpHu), intermediate pHu (5.8-6.2, IpHu) and high pHu (≥6.2, HpHu) Longissimus lumborum from beef. During 21 d of ageing, the HpHu group had the lowest Warner-Bratzler shear force (WBSF) values, while the IpHu group showed the highest and even after 21 days of ageing still had high levels. In the late stage of the 24 h post-mortem period the faster degradation rate of troponin T and earlier activation of caspase 9 in the HpHu group were the key reasons for the lower WBSF compared with the NpHu and IpHu groups. The activity of caspase 3 cannot explain the tenderness differences between IpHu and HpHu groups, since their activities did not show any difference. At 24 h post-mortem, 17 common differential phosphorylated peptides were detected among pHu groups, of which nine were associated with pHu and WBSF. The higher phosphorylation level of glycogen synthase may have caused the delay of meat tenderization in the IpHu group.

Sous vide cooking improved the physicochemical parameters of hot-boned bovine semimembranosus muscles

The physicochemical parameters of hot-boned bovine semimembranosus muscles after sous vide cooking were investigated. Hot-boned or wet-aged steaks were collected, and cooked by different cooking methods, including sous vide (57 °C, 11 h, SV), grilling (at 200 °C to the central temperature of 72 °C, GR) or boiling (100 °C, 2 h, BO). The meat color, tenderness, water-holding capacity, degree of oxidation, myoglobin denaturation and sensory quality traits were determined, as well as the changes in the microstructure. Compared to other cooking methods, SV reduced the degree of oxidation and muscle shortening, and significantly improved the water holding capacity (WHC), tenderness, connective tissue content and overall acceptability for both hot-boned and wet-aged steaks. The oxidation and muscle shortening were reduced in hot-boned SV steaks (P < 0.05), and the water-holding capacity and sensory scores for juiciness, connective tissue content and overall acceptability were increased (P < 0.05) compared to the wet-aged steaks. The combination of hot-boning and SV cooking resulted in an acceptable tenderness, better overall sensory acceptability and higher WHC than other combinations of muscle states and cooking methods. Therefore, it is a good choice to cook hot-boned semimembranosus muscles using SV to improve the eating quality, which can eliminate the need for aging, benefiting the beef industry.

Effect of ultimate pH on quality of aged Longissimus dorsi muscle of Zebu Nellore (Bos indicus) during long-term frozen storage

Despite the relatively high occurrence of bovine meat with intermediate to high ultimate pH (pHu), there is a lack of studies focused on the effects of long-term conventional air-blasting freezing storage on quality parameters of commercial beefs of Zebu Nellore (Bos indicus) with varying pHu ranges. The objective of this work was to evaluate the influence of pHu ranges [normal (≤5.79), intermediate (5.80 to 6.19), and high (≥6.20)] and long-term frozen storage on quality parameters of aged Longissimus dorsi beefs of Zebu Nellore (Bos indicus). The aging conditions were set at 2 °C for 14 days, while the freezing conditions were set at - 20 °C, and samples were collected after 3, 6, 9, and 12 months of storage. The results indicated that the pHu influenced meat quality parameters, as well as the chemical forms of myoglobin, which changed throughout the frozen storage, leading to a brighter red color, especially for the normal pHu beef samples, likely due to increased oxymyoglobin content. Frozen storage improved tenderness, with high pHu beef samples being the more tender after 12 months, potentially due to lower protein oxidation, as measured by the carbonyl content. Increased drip loss was observed over freezing time, with a concomitant decrease in protein solubility, especially for myofibrillar and sarcoplasmic proteins, which differed among the pHu ranges. These findings are valuable for determining freezing time as a preservation strategy to maintain beef quality within different pHu ranges.

Aging mechanism for improving the tenderness and taste characteristics of meat

Tenderness and taste characteristics of meat are the key determinants of the meat choices of consumers. This review summarizes the contemporary research on the molecular mechanisms by which postmortem aging of meat improves the tenderness and taste characteristics. The fundamental mechanism by which postmortem aging improves the tenderness of meat involves the operation of the calpain system due to apoptosis, resulting in proteolytic enzyme-induced degradation of cytoskeletal myofibrillar proteins. The improvement of taste characteristics by postmortem aging is mainly explained by the increase in the content of taste-related peptides, free amino acids, and nucleotides produced by increased hydrolysis activity. This review improves our understanding of the published research on tenderness and taste characteristics of meat and provides insights to improve these attributes of meat through postmortem aging.

Effect of age and diet on carcass and meat quality in ewes

This study elucidated the effect of age and diet on carcass characteristics and meat quality parameters of Rambouillet ewes. Forty ewes (n = 20 yearling ewes and n = 20 cull ewes) were fed with alfalfa hay (AH) or a 100 % concentrate diet (CD). Treatments were: a) 10 cull ewes were fed only with AH, b) 10 yearling ewes were fed only with AH, c) 10 cull ewes were fed with CD, d) 10 yearling ewes were fed with CD. Productive performance, carcass and meat quality were analyzed. Animals had ten days for adaptation and 35 days were used to collect data. Dry matter intake was greater (P < 0.05) for CD. Feed conversion rates were not affected by treatments. The pH at 45 min and 24 h, carcass length, leg length, leg width, thorax width, and thorax perimeter were not affected by treatments. Hot carcass weight was heavier (P < 0.05) in cull ewes, cold carcass weight was increased (P < 0.05) with CD. Carcass yield (CY) was heavier in CD (P < 0.05). Cull ewes had greater (P < 0.05) lean CIELAB L*, a*, b*, c*, and h* values compared to yearling ewes. The color changes increased with age at five days (P < 0.05), but a decrease (P < 0.05) with diet was observed at ten days. Cathepsins B, B + L, and Lowry protein content were not affected by treatments. In conclusion, feeding cull ewes with concentrate diets may enhance body weight gain and carcass yield compared to a diet based on 100 % alfalfa hay.

Descriptive beef flavor and texture attributes relationships with consumer acceptance of US light beef eaters

Consumer acceptance and overall liking has been shown to be related to beef instrumental and trained sensory attributes related to beef flavor, tenderness, and juiciness. Our objective was to understand the relationships between descriptive beef flavor and texture attributes, Warner-Bratzler shear force (WBSF), and consumer liking attributes for light US beef eaters. It is not known if light beef eaters have different drivers of overall liking. Treatments were created to differ in beef flavor and texture by utilizing different beef cuts (Choice top loin, high pH top loin, Select top sirloin, Choice tenderloin steaks, and Select and Choice bottom rounds roasts) cooked to 58 °C or 80 °C. Cooking methods included either a George Forman grill, food-service grill, or crock-pot. Cooking method, cut, and internal temperature impacted beef descriptive flavor and texture attributes, WBSF and consumer liking ratings (P ≤ 0.05) similarly. Descriptive juiciness and tenderness attributes were highly related to each other and with consumer juiciness and tenderness liking ratings. Consumer overall liking was closely related to descriptive fat-like, overall sweet, sweet and salty attributes. Musty/moldy, liver-like, and sour aromatic attributes were negatively associated with consumer liking. Overall flavor accounted for 85% of the variation in overall liking and tenderness liking contributed an additional 4%. While light beef eaters used different parts of the scale, they rated beef across treatments similarly. When beef flavor and texture descriptive attributes differed, consumer liking was impacted for light beef eaters.

Combination of ultrasound treatment and starter culture for improving the quality of beef jerky

The effects of treatment by ultrasound (US), inoculation of Pediococcus acidilactici BP2 strain (BP), and their combination (US-BP) on the quality characteristics of beef jerky were investigated during fermentation for 6 days. Moisture contents and water activity were highest after the US and US-BP treatments (P < 0.05). These effects were attributed to the decreased moisture mobility in beef jerky during ultrasonication. Meanwhile, samples treated with US and US-BP displayed more broken muscle fibers and larger gaps and cavities between the adjacent muscle bundles, resulting in lower shear force values compared to the other samples (P < 0.05), which indicated that the US and US-BP treatments improved the tenderness of beef jerky. Moreover, treatment with BP promoted the flavor development of beef jerky. The US-BP treatment improved the sensory attributes of beef jerky. In conclusion, US-BP is a promising strategy to improve the quality of beef jerky.

Evolution of lean meat tenderness stimulated by coordinated variation of water status, protein structure and tissue histology during cooking of braised pork

Tenderness of lean meat in braised pork is of great importance to the consumer palatability and acceptance. The influence of water status, protein structure and histological changes on lean meat tenderness during cooking was investigated. Results indicated that lean meat began to tenderize mainly after 20 min-cooking. In the early period of cooking, the decrease of total sulfhydryl content caused the protein oxidative cross-linking, leading to the gradual unfolding of the protein structure, thus resulting in a decrease of T₂₂ and an increase of centrifugal loss, which decreased the tenderness of lean meat. However, after cooking for 20 min, the β-sheet decreased and random coil increased, thus generating conversion between P₂₁ and P₂₂. The rupture of perimysium structure was observed. Changes in protein structure, water status, and tissue histology could facilitate the initiation and development of lean meat tenderness.

Differences in toughness and aging potential of longissimus lumborum muscles between Hanwoo cow, bull and steer

Thirty Hanwoo cattle including bulls, cows, and steers (n = 10 each) were slaughtered and investigated for carcass traits (weight, meat color, fat color, yield index, maturity, marbling score, back-fat thickness, and firmness) and meat quality. The meat quality such as: pH, color, cooking loss, fatty acid, thiobarbituric acid reactive substance, warner-bratzler shear force, tensile tests, and texture profiles were analyzed on longissimus lumborum (LL) muscles of the carcasses at different aging times (3 d and 21 d). The results showed that steers and cows had higher back-fat thickness and marbling score, and a lower firmness (p < 0.001) than bulls. Bulls exhibited a lower meat quality indicating by higher cooking loss, thiobarbituric acid reactive substance content, warner-bratzler shear force and tensile test values (p < 0.01). Regarding the sensory property, the bull meat also had higher hardness, and lower tenderness, juiciness and flavor scores than the cow or steer meat (p < 0.01). Additionally, the bull meat had a higher polyunsaturated fatty acid and a lower monounsaturated fatty acid contents (p < 0.01). With increased aging time, the meat tenderness was improved in all the genders. Taken together, the present study demonstrated that the gender and aging time affected the carcass traits, fatty acid and sensory quality of beef. Postmortem aging could improve the meat tenderness of all genders especially bulls.

Performance, carcass, and meat traits of locally adapted Brazilian cattle breeds under feedlot conditions

Little is known about the performance, carcass, and meat traits of locally adapted cattle in Brazil. This study aimed to compare the growth, slaughter, and carcass traits as well as meat quality of two local breeds (Curraleiro Pé-Duro and Pantaneiro) with the Nelore breed. Fifteen 30-month-old steers of each breed were weighted (Curraleiro Pé-Duro = 264.80 kg; Nelore = 346.80 kg; Pantaneiro = 316.20 kg) and raised in a feedlot condition for 112 days, with measurements to assess growth and slaughter, visual and carcass and meat traits. Data were submitted to variance and multivariate analyses. Nelore and Curraleiro Pé-Duro had similar Gluteus medius depths. Pantaneiro and Curraleiro Pé-Duro were superior for leg compactness index (P < 0.05) and had higher eye muscle area than Nelore (P < 0.05). Although there was no difference in daily weight gain and slaughter weight between breeds, Curraleiro Pé-Duro had a lower initial weight (264.80 kg) when compared to Nelore (346.80 kg; P < 0.05). Nelore and Curraleiro Pé-Duro deposited more fat than Pantaneiro (P < 0.05), while Curraleiro Pé-Duro and Pantaneiro had more muscle than Nelore (P < 0.05), which also had more bone and a higher percentage of second-quality cuts (P < 0.05). Meat from Nelore also showed lower succulence than Pantaneiro (P < 0.05) and higher shear force than the other breeds (P < 0.05). Pantaneiro's meat had the most capacity to retain water (P < 0.05), lower shear force (P < 0.05), and was more succulent (P < 0.05) when compared to the other breeds. Multivariate analysis showed that Pantaneiro, Curraleiro Pé-Duro, and Nelore breeds can be considered distinct in growth, carcass, and meat traits, with the local breeds showing superior meat traits. The local breeds Curraleiro Pé-Duro and Pantaneiro presented characteristics similar or better to those of the Nelore, proving to be animals with great productive potential and generate high meat quality under feedlot conditions.

Relationships between the abundance of 29 proteins and several meat or carcass quality traits in two bovine muscles revealed by a combination of univariate and multivariate analyses

We aimed to evaluate the relationships between meat or carcass properties and the abundance of 29 proteins quantified in two muscles, Longissimus thoracis and Rectus abdominis, of Rouge des Prés cows. The relative abundance of the proteins was evaluated using a high throughput immunological method: the Reverse Phase Protein array. A combination of univariate and multivariate analyses has shown that small HSPs (CRYAB, HSPB6), fast glycolytic metabolic and structural proteins (MYH1, ENO3, ENO1, TPI1) when assayed both in RA and LT, were related to meat tenderness, marbling, ultimate pH, as well as carcass fat-to-lean ratio or conformation score. In addition to some small HSP, ALDH1A1 and TRIM72 contributed to the molecular signature of muscular and carcass adiposity. MYH1 and HSPA1A were among the top proteins related to carcass traits. We thus shortened the list to 10 putative biomarkers to be considered in future tools to manage both meat and carcass properties. SIGNIFICANCE: In three aspects this manuscript is notable. First, this is the first proteomics study that aims to evaluate putative biomarkers of both meat and carcass qualities that are of economic importance for the beef industry. Second, the relationship between the abundance of proteins and the carcass or meat traits were evaluated by a combination of univariate and multivariate analyses on 48 cows that are representative of the biological variability of the traits. Third, we provide a short list of ten proteins to be tested in a larger population to feed the pipeline of biomarker discovery.

Early postmortem muscle proteome and metabolome of beef longissimus thoracis muscle classified by pH at 6 hours postmortem

The objective was to identify metabolome and proteome differences at 1 h and 1 d postmortem between longissimus thoracis (LT) muscle classified based on 6 h pH values. Twenty beef LT rib sections were sorted based on 6 h postmortem pH values into low (LpH; pH < 5.55; n = 9) and high (HpH; pH > 5.84; n = 8) pH classifications. Warner-Bratzler shear force (WBSF), desmin degradation, and calpain-1 autolysis were measured. Two-dimensional difference in gel electrophoresis (3-10, 4-7, and 6-9 pH range) and Tandem mass tagging (TMT) protein analyses were employed to determine how the sarcoplasmic protein profile varied across pH classification. Non-targeted metabolomic analyses were conducted on extracts prepared at 1 h and 1 d postmortem. The LpH classification had a lower WBSF value at 1 d postmortem, which was explained by greater calpain-1 autolysis and desmin degradation at 1 d postmortem. Proteome and metabolome analysis revealed a phenotype that promotes more rapid energy metabolism in the LpH group. Proteome and metabolome analyses identified energy production, apoptotic, calcium homeostasis, and proteasome systems influencing pH classifications that could explain the observed pH, proteolysis, and beef tenderness differences. SIGNIFICANCE: This study is the first to identify proteomic and metabolomic variations early (1 h and 1 day) postmortem that are linked to differences in early (6 h) postmortem pH values and to tenderness differences at 1 day postmortem. This study integrates postmortem biochemical features (protein degradation, proteome, and metabolome variations) to postmortem pH decline and eating quality of beef steaks. Potential biomarkers of more rapid postmortem metabolism linked to earlier tenderization in beef are suggested. Identification of these biochemical features will assist in predicting the eating quality of beef products.

A Rare Case of BIA-ALCL Mass Associated with Mastectomy Skin Flap Erythema After Immunization with COVID-19

BACKGROUND

The immune response to breast implants after COVID-19 disease or COVID-19 vaccine administration includes acute inflammatory manifestations, capsular contracture and seroma. Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a very rare tumor in which numerous up-regulated pro-inflammatory immunological pathways activate a T cell lymphoproliferative disorder.

METHODS

The first reported case of a BIA-ALCL hidden mass clinically manifesting with inflammatory signs after SARS-CoV-2 infection and vaccinations is here described.

RESULTS

Complete capsulectomy and adjuvant chemotherapy were performed and immediately after the surgical procedure local inflammatory signs disappeared; no evidence of disease was present 1 year later.

CONCLUSIONS

Immunological stimulation by COVID-19 disease and vaccines may highlight some rare clinical manifestations of BIA-ALCL; persistent inflammatory symptomatology over breast implants should be investigated using second-level imaging.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The underlying mechanisms of the effect of superchilling on the tenderness of beef Longissimus lumborum

This study investigated the effect of superchilling (-30 °C until the core temperature achieved -3 °C, then stored at -1 °C until 24 h, SC) on the tenderness of hot boned beef M. longissimus lumborum (LL), with very fast chilling (-30 °C until the core temperature achieved 0 °C, then stored at -1 °C until 24 h, VFC) and conventional chilling (0- 4 °C for 24 h, CC) as the controls. The lowest initial shear force values were obtained in SC samples compared to those from the VFC and CC treatments (P < 0.05). Clear freezing damage of muscle fibers and more myofibril fragmentation were found in SC samples compared with the other samples early post-mortem. Moreover, SC samples showed the highest level of inosine 5-monophosphate at 3 h post-mortem (P < 0.05). A reduced glycolysis rate (as evidenced by lactate content) was also found in SC treated samples suggesting little contribution of glycolysis on the tenderization of SC.

Physical properties during a 28-day ageing period of blesbok (Damaliscus pygargus phillipsi) Longissimus thoracis et lumborum and Biceps femoris muscles

The study aimed to determine the effect of sex, muscle-type, and ageing on the physical properties of blesbok (Damaliscus pygargus phillipsi) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscles. Randomly assigned steak samples from twenty mature blesbok (10 of each sex) antelope were vacuum-packed and stored at 4.4 ± 1 °C for 2, 4, 7, 10, 17 and 28 ageing days. Cumulative purge loss, pH, colour (L*, a*, b), cooking loss, and Warner Braztler shear force were determined. Males had meat with higher (P = 0.032) pH values than females, while all other attributes were similar (P > 0.05). The LTL had greater (P < 0.05) purge losses, L* and a* values than the BF muscle, while other quality attributes were greater (P < 0.05) for the BF muscle. Despite fluctuations, there was an overall decrease in shear force with ageing time. According to all quality parameters measured, the optimum ageing period for blesbok would seem to be 10 days.

Effect of dietary resveratrol supplementation on muscle fiber types and meat quality in beef cattle

In order to investigate the effect of dietary resveratrol supplementation on muscle fiber types and meat quality in beef cattle, a feeding experiment was undertaken. Longissimus lumborum, Psoas major and Semitendinosus muscles were collected 24 h post-mortem from two groups of cattle, which were fed with a total mixed ration (Control - CON) or supplemented with resveratrol (5 g/animal/day, RES) for 120 d before slaughter. The results showed that dietary resveratrol increased the gene expression of MyHC I and enhanced the proportion of type I fibers in three muscles. The cooking loss and Warner-Bratzler shear force of all muscles during aging for 21 days were decreased. However, the increased proportion of type I fibers resulted in a darker initial color, but did improve color stability, as the a* value of RES samples was lower initially but higher in the later stage of aging. This study indicates the supplementation potential of resveratrol for beef cattle for tenderness and color stability.

H2O2-induced oxidative stress improves meat tenderness by accelerating glycolysis via hypoxia-inducible factor-1α signaling pathway in postmortem bovine muscle

Reactive oxygen species (ROS) affect meat quality through multiple biochemical pathways. To investigate the effect of ROS on postmortem glycolysis and tenderness of bovine muscle, ROS content, glycolytic potential, glycolysis rate-limiting enzyme activities, expression of hypoxia-inducible factor-1α (HIF-1α), phosphatidylinositol 3-kinase (PI3K), serine-threonine kinase (AKT), phosphorylated AKT (p-AKT), and tenderness were determined in the H₂O₂ group and control group. Results showed that the H₂O₂ group exhibited significantly higher ROS content within 48 h, coupled with increased glycolytic potential, pH decline, hexokinase (HK), and phosphofructokinase activities (PFK) early postmortem. These were attributed to ROS-induced PI3K/AKT signaling pathway activation and resultant HIF-1α accumulation. Moreover, shear force in the H₂O₂ group reached the peak 12 h earlier and decreased obviously after 24 h, accompanied by a significantly higher myofibril fragmentation index (MFI). These findings suggested that ROS drive HIF-1α accumulation by activating PI3K/AKT signaling pathway, thereby accelerating glycolysis and tenderization of postmortem bovine muscle.

Proteomic and parallel reaction monitoring approaches to evaluate biomarkers of mutton tenderness

Intensive fattening usually results in the changes of meat quality. Tenderness is a central attribute for mutton sensory qualities and consumers' choice. Here, we reported that intensive fattening mutton was more tender than that of traditionally raised sheep. By proteomic approach, we found 49 differentially expressed proteins in longissimus dorsi muscle. After bioinformatics analysis, 5 cytoskeletal proteins, 3 protein binding proteins and 7 metabolic enzymes were identified as potential biomarkers for mutton tenderness. Finally, we verified the expression of these abundant proteins by parallel reaction monitoring (PRM). Collectively, our results reveal that the mutton of sheep raised by intensive fattening is more tender than that of traditionally raised sheep. Myosin-2, myosin-13, vimentin, carbonic anhydrase, carbonic anhydrase-2, Glutathione S-transferase and Microtubule-associated protein 4 isoform X1 can be candidate biomarkers for mutton tenderness. Our data also indicate a central role of cytoskeletal proteins and metabolic enzymes in determining mutton tenderness.

Physical meat quality characteristics of Angolan giraffe (Giraffa giraffa angolensis) as affected by sex and muscle

Giraffe numbers grow exponentially when farmed, necessitating periodic culling. This study quantified the effect of sex and muscle on the physical quality characteristics of eight giraffe muscles. The Warner-Bratzler shear force (WBSF) was the only parameter to be affected by an interaction between sex and muscle (P < 0.001), although the interaction for the CIE L* values tended towards significance (P = 0.054). Cooking loss (male = 41.6 ± 0.35%; female = 40.7 ± 0.33%; P = 0.024) and CIE L* values (male = 38.8 ± 0.23; female = 37.3 ± 0.27; P = 0.039) were both affected by sex. Muscle had an effect on all physical parameters. The ultimate pH of all muscles was 5.5-5.9; the average WBSF of <43 N for all muscles indicates giraffe meat in this study is tender. This study shows that yield and physical characteristics of giraffe meat are favourable, and the results may be useful for the marketing of giraffe meat.

Color attributes and myoglobin chemistry exhibit relationships with tenderness and calpain-1 abundance in postmortem Longissimus lumborum muscles from Holstein heifers

The objective of this study was to determine the extent that myoglobin and beef color are associated with calpain-1 relative abundance relative and tenderness. Longissimus lumborum (LL) samples from the left side of Holstein beef carcasses (n = 31) were collected immediately post-evisceration for 0 h analyses. At 48 h postmortem six steaks were removed from the right side of each carcass for analyses at 48 and 336 h postmortem. Myoglobin concentrations resulted in negative correlations (P < 0.05) to Warner-Bratzler shear force (WBSF) values at 336 h postmortem. L*, a*, and b* values at 48 h resulted in positive correlations (P < 0.05) with WBSF values at 48 and 336 h. Values for b* at 336 h had positive correlations with calpain-1 concentration at 0 and 336 h. Data from this study indicate a potential relationship between myoglobin concentration and meat color with tenderness aspects and calpain-1 relative abundance.

Mischievous mandibular third molars camouflaging temporomandibular joint disorders

Objectives

The aim of this study was to observe the relationship between impacted mandibular third molars and development of temporomandibular joint (TMJ) disorders. Knowledge of the factors that have an adverse effect on the TMJ is necessary for proper diagnosis, treatment, and prognosis of TMJ disorders.

Materials and Methods

The study was performed on 80 patients aged between 20 and 60 years with impacted mandibular third molars, over a period of two months. The patients were examined clinically and radiologically to determine the type of impaction and detect the associated TMJ symptoms or disorders.

Results

In the 80 patients, 63.8% (51/80) of TMJ disorders were found in the horizontal group, 46.3% (37/80) in the mesioangular group, 42.5% (34/80) in the distoangular group, and 30.0% (24/80) in the vertical group of impacted mandibular third molars.

Conclusion

The study concluded that type of impacted mandibular third molar is factor in the development of temporomandibular disorders.

Comparison between exercise therapy and non-hydrolyzed collagen (UC-II) in functionality and quality of life in women with knee osteoarthritis : A randomized controlled clinical trial

BACKGROUND

Knee osteoarthritis (OA) is characterized by a progressive degeneration of cartilage and menisci, leading to pain and locomotor disability. Here, we aimed to assess the effect of an exercise protocol and the oral use of non-hydrolyzed collagen (UC-II) on the functionality and quality of life of women with knee OA.

MATERIAL AND METHODS

Individuals were divided into three groups (CG [control group]; MG [medication group]; EG [exercise group]). In the CG there was no intervention, while MG received an oral dose (1 capsule/day) of UC-II and the EG held 12 sessions of an exercise protocol.

RESULTS

In the functionality tests (6-min walk test, 6MWT and timed up and go test [TUG]) the EG (p < 0.001/p = 0.020) and MG (p = 0.010/p = 0.010) revealed a significant improvement when compared to the CG. In the analysis of quality of life by WOMAC, a significant improvement was found only in the EG (p = 0.030) when compared to the CG; the same happened in the stiffness domain (EG, p = 0.010), despite in the pain domain, both the EG (p < 0.001) and the MG (p = 0.060) were better than the CG.

CONCLUSION

Data obtained here reveal that an exercise protocol and UC-II have similar effects for functionality, despite exercise being superior in promoting the quality of life score.

Evaluation of effects of ultrasound-assisted saucing on the quality of chicken gizzards

The purpose of this study was to evaluate the effects of ultrasound-assisted saucing on the quality of chicken gizzards. The results showed that with the prolonging of the saucing time, the yield, water holding capacity (WHC), lightness (L*), redness (a*) and springiness of chicken gizzards significantly decreased, while the shear force, hardness and chewiness significantly increased (P < 0.05). When the saucing time was the same, the yield, WHC, springiness and tenderness of the ultrasound group were significantly higher than those of the non-ultrasound group (P < 0.05). In particular, when the saucing time was 30 min, the yield, WHC and springiness of the ultrasound group increased by 2.13%, 0.97% and 10.53%, and the shear force decreased by 21.22% compared with those of the non-ultrasound group, respectively. Besides, ultrasound pretreatment increased the content of aromatic compounds, short-chain alkanes, alcohols, aldehydes and ketones, and the principal component analysis displayed that C-50 (saucing for 50 min without ultrasound pretreatment) and U-30 (saucing for 30 min with ultrasound pretreatment) were similar in flavor. Therefore, ultrasound pretreatment is a potential way to improve the quality of saucing chicken gizzards and shorten the processing time.

Sexual Activity and Physical Tenderness in Older Adults: Prevalence and Associated Characteristics From a Belgian Study

BACKGROUND

Despite the World Health Organization calling for sexuality to be recognized as an aspect of well-being, no studies have explored sexual activity and physical tenderness in older adults aged ≥ 75 years in Belgium or those aged ≥ 85 years worldwide.

AIM

To assess the prevalence and predictors of sexual activity and physical tenderness in a sample of older adults.

METHODS

Using data from a Belgian cross-sectional study on sexual violence (UN-MENAMAIS), information on sexual activity, physical tenderness, and associated characteristics was collected during structured face-to-face interviews with older adults living in the community, assisted living facilities, or nursing homes. Cluster random probability sampling with a random route-finding approach was used to select the participants.

OUTCOMES

Current sexual activity and physical tenderness in the previous 12 months, sociodemographic characteristics, chronological age, subjective age, number of sexual partners, sexual satisfaction, attitudes toward sexuality in later life, quality of life, and lifetime sexual victimisation.

RESULTS

Among the 511 participants included, 50.3% were in a relationship, mainly living with their partner; 31.3% indicated they were sexually active; and 47.3% of sexually inactive participants reported having experienced forms of physical tenderness in the previous 12 months. Sexual activity was associated with the presence of a partner, satisfaction with sexual life, permissive attitudes regarding sexuality in later life, a younger age, and a lack of disability. Physical tenderness was associated with the presence of a partner, community residency, and permissive attitudes regarding sexuality in later life.

CLINICAL IMPLICATIONS

Raising awareness among the general population, healthcare professionals, and older adults about sexuality in later life could contribute to ending this taboo and should therefore be a priority for society.

STRENGTHS AND LIMITATIONS

Our study fills a gap in the literature regarding sexual activity and physical tenderness in older adults aged ≥ 70 years, including respondents aged up to 99 years. Additionally, we explored different forms of sexual expression beyond intercourse, and face-to-face interviews contributed to the quality of the collected data. The main limitation of this study was the sample size, although the findings were similar to recent statistical indicators in Belgium.

CONCLUSION

One in 3 older adults aged ≥ 70 years living in Belgium are sexually active. These findings provide an opportunity to inform the general public and older adults about later life sexuality and to educate healthcare professionals about aging sexuality to increase discussions and avoid assumptions of asexuality in later life. Cismaru-Inescu A, Hahaut B, Adam S et al. Sexual Activity and Physical Tenderness in Older Adults: Prevalence and Associated Characteristics From a Belgian Study. J Sex Med 2022;19:569-580.

Effects of caspase activity of yak meat and internal environment changing during aging

The objective of this study was to investigate the protease family caspases in skeletal muscle and their potential contribution to postmortem proteolysis and meat tenderization. Nine yaks were slaughtered, and samples of Longissimus dorsal were injected with AC-DEVD-CHO at a ratio of 1:1 (w/v) and then stored at 4 °C for 2, 6, 12, 24, 72, and 120 h. Results indicate that the morphological changes of the muscle fibers are significantly obstructed, which is not conducive to the subsequent degradation of proteins. After inhibiting the activity of Caspase- 3, the activity of Caspase-8 and 9 and the energy metabolism was affected. In the case of without inhibition of caspase, the pH value decreased and then increased. The meat color and the water retention are better, the muscle fiber skeleton protein degradation is remarkable, the tenderness is improved. Furthermore, yak meat tenderness was improved by apoptotic pathway during aging.

Meta-analysis of the relationship between collagen characteristics and meat tenderness

Meta-analysis methods were used to investigate the effects of collagen content, solubility and pyridinoline cross-link content on Warner-Bratzler shear force (WBSF) and sensory tenderness in major meat species. Data was collected from the literature on pork, beef and lamb and analyzed independently for each species. The beef data was categorized into subgroups according to muscle (loin and other muscle) and age (young, <18 months and old, ≥18 months). The results showed that in beef, collagen content and pyridinoline cross-link content were positively correlated with WBSF and negatively with sensory tenderness, while collagen solubility was negatively correlated with WBSF. The correlation coefficients were greater in other beef muscles than loin. Significant correlations between collagen content and tenderness attributes were observed in old beef animals. However, non-significant relationships and large variations were found in pork and lamb. More studies with various muscles and ages are required for an in-depth understanding of the relationship between collagen characteristics and meat tenderness.

Long-term effects of early maternal undernutrition on the growth, physiological profiles, carcass and meat quality of male beef offspring

The effects of maternal undernutrition in early gestation on growth, metabolic and endocrine profiles, carcass and meat quality of male offspring in cattle were assessed. Twenty-one Parda de Montaña and 14 Pirenaica cows received a CONTROL (100% nutrition requirements) or a SUBNUT (65%) diet from day 0 to 82 of gestation and thereafter were fed to requirements until calf weaning at 4 months of age. The performance and physiological profiles of male offspring during an 8-month fattening period were analyzed. Bulls were slaughtered at 12 months of age, and their carcasses and meat color, tenderness and intramuscular fatty acid profile were evaluated. Maternal undernutrition increased plasma NEFAs and impaired the growth of Pirenaica bulls, resulting in lower weights at slaughter and fatter carcasses with impaired meat tenderness. Irrespective of the breed, maternal undernutrition affected meat color and increased the meat content of some healthy fatty acids. In summary, early maternal undernutrition affected the fetal programming of beef male offspring with persistent consequences at slaughter.

Application of ultrasound treatment in chicken gizzards tenderization: Effects on muscle fiber and connective tissue

The tenderizing effect of different ultrasound treatments on the characteristics of muscle fibers and connective tissue of chicken gizzard was investigated. It could be concluded that the shear force and muscle fiber diameter of the sample treated with ultrasound for 500 W/30 min were decreased by 27.1% and 26.2%, respectively, while the myofibril fragmentation index (MFI) was increased by 238.1% than the control. More importantly, the contents of hydroxylysine pyridinoline and lysine pyridinoline of the samples treated with ultrasound for 500 W/30 min were 23.1% and 40.5% lower than those of the control. Tenderizing effect of 500 W/30 min sample on thermal stability was verified from the decrease in transition temperature (Tmax) (10.7%) and enthalpy (ΔH) (21.7%) of collage compared with the control. In general, proper ultrasound treatment could effectively improve the tenderness of gizzard, and 500 W/30 min had the best tenderization effect. Therefore, the treatment of ultrasound was considered as a promising and efficient technique in meat processing, especially for the meat tenderization.

Feeding strategies and ageing time alter calpain system proteins activities and meat quality of Braford steers

Objective

The aim of this study was to evaluate the effect of ageing and feeding strategies on the calpain protease system and meat quality traits in Braford steers.

Methods

Thirty Braford steers were employed; 15 animals were supplemented with corn silage during finishing and 15 were kept only on pasture. Meat quality traits and calpain system protein activity were evaluated in longissimus thoracis et lumborum (LTL) steaks aged for 2, 7, 14, and 21 days.

Results

Aged meat showed higher pH and calcium content, while Warner Bratzler shear force (WBSF) decreased to day 21. No interaction between ageing and diet was seen for quality traits. Steers finished with corn silage showed higher values of water holding capacity, WBSF and free calcium, and lower values of pH and cooking loss. Calpain and calpastatin activities decreased with ageing. Finishing steers on pasture produced higher values of calpains and lower values of calpastatin activities. The higher values of calpain 1 activity were observed in muscles aged 2 days from pasture finished animals, and the lower activity of the inhibitor in the 21 days aged samples of the same group.

Conclusion

These results suggest a diet by ageing interaction in calpains and calpastatin and this interaction impact in Warner Bratzler Shear Force in Braford LTL muscle.

Focusing on intramuscular connective tissue: Effect of cooking time and temperature on physical, textual, and structural properties of yak meat

This study aimed to evaluate the effects of different cooking time (2, 4, and 6 h) and temperature (50, 60, 70, 80, and 90 °C) on physical, textual, and structural properties of longissimus lumborum muscle of yak, and to explore the thermal denaturation process of intramuscular collagen by using a new tool (collagen hybridizing peptide staining, CHP staining). The results showed that tenderness was affected by the interaction of cooking time and temperature and the changes in moisture and collagen composition. In comparison with cooking time, temperature had more obvious effects on cooking loss, moisture content and redness. Scanning electron microscopy showed that as the temperature increased, intramuscular connective tissue gradually degraded, and muscle fibers became more compact. CHP staining showed that the collagen in the perimysium first denatured at 50 °C, and more and more collagen denatured and degraded as the temperature increased.

Influence of aging time, temperature and relative humidity on the sensory quality of dry-aged Belgian Blue beef

The objective of this study was to evaluate the effect of aging period (0, 3, 6 or 9 weeks), aging temperature (2 versus 6 °C at 75% relative humidity, experiment 1) and relative humidity (70 versus 90% at 2 °C, experiment 2) on the sensory traits, oxidative stability and proteolysis of Belgian Blue beef. For each experiment, eight loins (M. longissimus thoracis et lumborum) from four animals (left and right side) were assigned to one of the two treatments (n = 4). Results showed no further tenderization after three weeks of aging, whereas metmyoglobin formation and lipid oxidation increased until nine weeks of aging (P < 0.05). During the nine weeks of aging, atypical flavor, odor and flavor intensity was affected (P < 0.05). This was accompanied by an increase of small peptides and other nitrogenous compounds. Aging temperature and relative humidity had only a very limited effect on the quality traits.

Proteomics analysis to investigate the impact of diversified thermal processing on meat tenderness in Hengshan goat meat

During the thermal processing, proteins of Hengshan goat meat undergo structural modifications such as degradation, oxidation and denaturation, ultimately affect the palatability and acceptability. The results of several objective metrics demonstrated that thermal processing exhibited significant impacts on the tenderness of goat meat. The 551, 84, 72, and 121 proteins were identified in the control and thermal processed groups (boiled, steamed, and roasted), respectively. Compared with the control group, the 101, 98, and 109 differentially-expressed proteins were explored in the treatment groups. Furthermore, the functions of metabolic and skeletal muscle proteome were investigated and discussed. Sensory evaluation and proteomics analysis showed that steaming and boiling treatment had no significant effect on the tenderness of goat meat, while roasting significantly reduced the tenderness, indicating that the available thermal processing methods to ensure the tenderness of goat meat were steaming and boiling treatments. Thus, the established proteomics database of goat meat provided the valuable reference for rational selection of thermal processing methods.

Biochemical and textural changes in beef from bulls and steers of different crossbreeds shortly after slaughter and during ageing

The aim of this study was to investigate the course of glycogenolysis, ATP breakdown and fragmentation of myofibrillar proteins in the semitendinosus muscle of a progeny of Limousin×Holstein-Friesian (LM_x) and Charolaise×Holstein-Friesian (CH_x) (bulls and steers) and to describe the changes in the above parameters over time and its relationship with beef texture. The hypothesis that beef from bulls and steers of different crossbreeds required the same ageing time to achieve satisfactory tenderness was also tested. Cattle crossbreeding did not affect the amount of muscle glycogen, and castration did not differentiate it until 3 h post-mortem. The interaction between crossbreeding and castration was found, and the highest shear force values were observed in CH_x bulls, whereas the lowest was in CH_x steers. Beef obtained from CH_x was found to be more predestined to short ageing, and LM_x required longer ageing to achieve good tenderness. The R-values more strongly influenced subsequent beef texture than pH values.

High hydrostatic pressure combined with moisture regulators improves the tenderness and quality of beef jerky

The influence of high hydrostatic pressure (HHP) at different pressure levels (0.1, 100, 200, and 300 MPa) combined with moisture regulators (MR) on the tenderness, water content, and quality of beef jerky was investigated. HHP treatment reduced the shear force (SF) of beef jerky (P < 0.05). The beef jerky treated with MR+HHP exhibited higher tenderness than the beef jerky treated only with HHP (P < 0.05). The MR+HHP samples had significantly higher moisture content than the HHP samples (P > 0.05) when the water activity was maintained at approximately 0.7. MR+HHP contributed to a shorter T₂₁ value and a higher P₂₁ value, which indicated an improvement in the water-binding ability of the beef muscle. Analysis of the microstructure showed that MR+HHP led to the fracture of the Z-line and destruction of the sarcomere structure. Sensory analysis showed that MR+HHP-200 samples had significantly higher tenderness and overall acceptable scores than other samples (P < 0.05).

Effect of three different proteases on horsemeat tenderness during postmortem aging

In this study, the semitendinosus of horse meat was used as the raw material. The study assessed the variation of the tenderness of horse meat during postmortem aging through the injection of papain, bromelain and fungal protease. The cooking loss of the horse meat became worse during postmortem aging. Low concentration of protease improved water retention properties of horse meat. Papain, bromelain and fungal protease had significant influence on MFI and shear force. MFI increased obviously but the shear force decreased significantly with the addition of more protease (p <0.05). During postmortem aging, many small molecules popeptide appeared in treatment group. Myosin light chain 2, 20 KDa, 32 KDa and 75 KDa bands appeared at first, however later they disappeared in the group with high concentration of protease treatment in addition to the disappearance of Desmin and Troponin I. The muscle fiber, perimysium and endomysium were degraded because of papain, bromelain and fungal protease treatment. More muscle fiber fragments appeared during postmortem aging.Thus, the tenderness and eating quality of horse meat were improved by adding three kinds of protease.

The influence of age and gender on the quality of raw and roasted wild boars (Sus scrofa) meat

The aim of this study was to determine the influence of age and gender on the chemical composition, colour, texture and sensory attributes of wild boars meat (Sus scrofa, n = 48). The animals were analysed in 6 groups (n = 8), differed in age (piglets below 1 year, yearlings 1-2 years, and adults over 2 years) and gender (male and female). Protein content in raw meat was affected by age, whereas in roasted meat by animals gender. Colour parameters, excluding lightness, were affected by animals age and values of a*, b* and C increased along the animal age. Roasted meat from piglets showed the lowest hardness and chewiness in TPA test, however shear force was similar for piglets and yearling, yet lower than adults. Age affected sensory quality of roasted meat and meat from yearlings was scored higher than from adults. The results of the study clearly indicate the predominant influence of wild boar age over gender on the meat quality.

Physicochemical characteristics and textural parameters of restructured pork steaks hydrolysed with bromelain

Enzymatic tenderisation including bromelain enhances underused cuts of meat in emerged restructuring technology. Physicochemical and textural characteristics of restructured pork steak hydrolysed with bromelain for masticatory dysfunction people were evaluated. Restructured pork steak treated with bromelain at 0.05 and 0.1% (w/w) was hydrolysed at 50 °C for 0, 3, 6, 9 and 12 min. The cooking losses of 0.05% (w/w) bromelain for 0, 3 and 6 min were lower than 0.1% (w/w) bromelain samples. The ΔE increased after increasing the enzyme concentration and hydrolysis time. Bromelain-treated samples at higher concentrations showed lower WBSF, KSF and TPA parameters, but cohesiveness of 0.05% (w/w) had higher than 0.1% (w/w) bromelain samples. Total protein, sarcoplasmic protein solubility, TCA-soluble peptide, total collagen and soluble collagen contents were the highest in 0.1% (w/w) bromelain-treated samples for 12 min (P < 0.05). According to SDS-PAGE and SEM, various proteins in the enzyme-treated samples were degraded.

Tenderness-related index and proteolytic enzyme response to the marination of spent hen breast by a protease extracted from Cordyceps militaris mushroom

Objective

The effects of a crude protease extracted from Cordyceps militaris (CM) mushrooms on the postmortem tenderization mechanism and quality improvement in spent hen breast were investigated.

Methods

Different percentages of the crude protease extracted from CM mushrooms were introduced to spent hen breast via spray marination, and its effects on tenderness-related indexes and proteolytic enzymes were compared to papain.

Results

The results indicated that there was a possible improvement by the protease extracted from CM mushroom through the upregulation of endogenous proteolytic enzymes involved in the calpain system, cathepsin-B, and caspase-3 coupled with its nucleotide-specific impact. However, the effect of the protease extracted from CM mushroom was likely dose-dependent, with significant improvements at a minimum level of 4%. Marination with the protease extracted from CM mushroom at this level led to increased protein solubility and an increased myofibrillar fragmentation index. The sarcoplasmic protein and collagen contents seemed to be less affected by the protease extracted from CM mushroom, indicating that substrate hydrolysis was limited to myofibrillar protein. Furthermore the protease extracted from CM mushroom intensified meat product taste due to increasing the inosinic acid content, a highly effective salt that provides umami taste.

Conclusion

The synergistic results of the proteolytic activity and nucleotide-specific effects following treatments suggest that the exogenous protease derived from CM mushroom has the potential for improving the texture of spent hen breast.