Longissimus Lumborum Research Articles

Red propolis extract reduces the lipid oxidation of lamb meat

Context Brazilian red propolis stands out for its diverse composition, which includes phenolic compounds whose effects may be similar to those of synthetic feed additives. Aims The objective of this study was to evaluate the effects of red propolis extract on the carcass and meat characteristics of lambs finished under confinement conditions. Methods The meat quality characteristics of the longissimus lumborum muscle were evaluated in 35 Santa Inês lambs, with an average age of 5 months and an initial average body weight of 17.08 ± 2.36 kg (mean ± s.d.), submitted to five distinct treatments (0, 7, 14, 21, 28 mL of red propolis extract/animal.day) over 68 days. Key results The use of propolis did not affect (P > 0.05) the characteristics of the carcass, as well as the chemical composition and cholesterol content. Among the physico-chemical parameters of meat, only the shear force had a quadratic effect (P < 0.05). There was also an exponential effect for lipid oxidation (P < 0.05), where the treatment with propolis had greater antioxidant effect. Meat with a lower content (P < 0.05) of saturated fatty acids was observed in sheep that received extract. There was also an increase (P < 0.05) in the content of monounsaturated acids and consequently an improvement in nutritional quality, atherogenicity and thrombogenicity indexes of desirable fatty acids. Conclusions The red propolis extract improved the lipid profile of the lamb meat. We recommend the inclusion of 7 mL red propolis extract/animal.day (or 59.50 mg total flavoloids/animal.day) in the diet of lambs finished under confinement conditions. Implications The red propolis extract proved to be a viable alternative as a natural feed additive.

Assessing the impact of ultrasound on the rate and extent of early post-mortem glycolysis in bovine Longissimus thoracis et lumborum

The rate of pH decline, early post-mortem, has been identified as a key factor that impacts the tenderness of meat, and manipulating this rate of pH decline is highly relevant to ensure consistent high quality meat. Ultrasound is a potential intervention in early post – mortem muscle that may have an impact on the rate of glycolysis through its ability to alter enzyme activity. Following a variety of different ultrasound treatments frequencies (25 and 45 kHz) and durations (15, 30 and 45 min), it was found, when analysed in muscle, that ultrasound treatment duration, specifically the 30 min treatment, and interaction between treatment duration and frequency, had a significant impact on the rate of pH decline, post – treatment. Frequency did not have a significant effect on the rate of pH decline, post – treatment, in muscle. Ultrasound did not have a significant permanent effect on the activity of glycolytic enzymes present in bovine Longissimus lumborum et thoracis muscle, where no significant differences were observed on the rate of pH decline and rate of change of reducing sugars, glycogen and lactic acid, when analysed in an in vitro glycolytic buffer. It seems that the impact observed in intact muscle is not as a consequence of a permanent change in enzymatic activity, instead indicating an impact on conditions in the muscle which enhanced enzyme activity.

Essential and toxic elements analysis of wild boar tissues from north-eastern Romania and health risk implications

IntroductionThe level of essential minerals in meat is an important factor in human nutrition and health. Meat from responsibly managed wildlife is an alternative raw material with considerable nutritional benefits. Meat from hunted animals has essential and non-essential elements for the human body. It is important to carefully monitor the levels of heavy metals accumulated in the tissues of hunted animals in polluted areas to ensure food safety and environmental contamination. High levels of heavy metals in food and the environment can pose a danger to human health.MethodsThe study aims to investigate the levels of essential mineral elements and heavy metals in the muscle tissue and organs of wild boar harvested through the herd density control plan over the last decade in north-eastern Romania.Results and discussionThe statistical analysis indicates that the age of the animals had a significant impact on Fe, Cu, and Zn levels in Longissimus lumborum. In the kidney a highly significant difference in Fe content by sex, with males showing higher values than females. The sex was shown to significantly influence the Mg levels. However, there are concerns about the accumulation of heavy metals such as Lead (Pb) and Cadmium (Cd), which may hurt the health of game meat consumers in the study area. Cd level it shows significant differences according to both age and sex, with higher concentrations in adults and males. Statistical analysis shows a negative correlation between Fe and Zn concentrations in muscle samples, while a positive correlation was found between Fe and Mn in kidney samples. There was also a positive association between Zn and Cu in muscle samples, but a negative association in kidney samples. Principal component analysis shows significant variation in essential element and heavy metals data between muscle and kidney samples. The loading plot shows a direct correlation between Pb and Cu and between Pb and Cd. However, an opposite correlation also is observed between Cu and Mg, Cd and Mg, and Pb and Mg. HQ (Hazard Quotient) for children compared to adults indicates a potentially higher risk associated with meat consumption among children because children are more vulnerable than adults. We report for the first time, to the best authors’ knowledge, various levels of essential minerals and exceeded maximum admitted level of heavy metals in the muscle tissues and kidneys of Sus scrofa ferus from Romania intended for human consumption, moreover, our findings highlight the need for strict monitoring and implementation of appropriate corrective measures, given the significant percentages of muscle and kidney samples exceeding the allowable limits for two of the most common toxic metals in the environment.

The quality and nutritional value of beef from Angus steers fed different levels of humate (K Humate S100R)

This study compared the effect of four levels of K Humate S100R (potassium humate) supplementation on the quality, shelf-life, and nutritional properties of beef. Angus steers (n = 40) were individually housed and fed either 0, 35, 70, or 140 g K Humate S100R/animal/day for 100 days, following a 30 day adjustment period. The steers were slaughtered at the completion of the feeding study. The left m. longissimus lumborum (LL) was collected at 24 h post-mortem and aged for either 2 or 6 weeks before analysis. K Humate S100R supplementation did not affect beef drip loss, cooking loss, shear force, sarcomere length, ultimate pH, intramuscular fat content, or total volatile basic nitrogen concentrations (P > 0.05). Steers supplemented with 70 g/day K Humate S100R produced beef with higher a* values on Days 1 and 3 of retail display (P < 0.05). Beef mineral composition was unchanged by K Humate S100R supplementation (P > 0.05), but there were minor changes to the fatty acid profile. Specifically, the ratio of omega-6 to omega-3 (P < 0.05) and C20:2n-6 concentrations (P < 0.05) increased with supplementation level. Together, these results demonstrate no detrimental effects on beef quality and shelf-life as a result of K Humate S100R supplementation.

The potential of the mineral composition to discriminate between beef from different cattle diets and between individual muscles

The effect of the diet of cattle on the mineral composition of various beef muscles was investigated. Both dietary treatment and muscle type influenced the mineral composition (Na, Mg, P, K, Ca, Mn, Fe, Ca, Zn and Se) of beef. The possibility of discriminating beef according to its dietary background and between muscle types was also investigated. Two canonical discriminant analysis models were developed and validated using the mineral concentrations in four muscles (supraspinatus, semitendinosus, longissimus lumborum and psoas major) from cattle reared completely on grass pasture, barley-based concentrate or grass silage with added concentrate combinations. The results demonstrate that the models could correctly classify grass-, partially grass- and concentrate-fed beef (accuracy = 80.7–94.9%) and the different muscles (accuracy = 81.4%). The discriminant models extracted characteristics of Irish grass-fed beef from the mineral composition and this has the potential for distinguishing grass-fed beef from beef raised on other diets.

A Study on the Modifying Effect of Raspberry Seed Oil on Rabbit Meat Quality and Chemical Composition.

The purpose of the study was to determine the effects of raspberry seed oil on the slaughter performance traits, plasma lipid concentration and meat quality of purebred Termond White rabbits (n = 42; 18♂, 24♀). In each group (3 × n = 14; 6♂, 8♀), the experimental animals were fed a complete pelleted feed with constant access to drinking water. Rabbits in the first experimental group received a feed ration enriched with a 1% addition of raspberry seed oil, while rabbits in the second experimental group were given a 2% addition of the same oil. These animals were slaughtered on day 84. The addition of raspberry seed oil did not significantly affect the slaughter performance traits of the rabbits (p > 0.05). It also did not significantly affect the fat content, shear force, hardness, springiness, cohesiveness or chewiness of the meat obtained from the rabbits' longissimus lumborum muscle. However, the experiment showed that the addition of raspberry seed oil had a significant effect on the fatty acid profile of rabbit meat (p ≤ 0.05). Even a small share of this oil in the feed ration significantly increased the level of linoleic acid (p ≤ 0.05). This study showed that feeding pellets containing an oil supplement with a high content of unsaturated fatty acids had a positive effect on rabbits' plasma lipid levels.

Effect of ultrasonic processing on beef tenderness in longissimus lumborum during aging by proteomics analysis

This investigation was aimed to evaluate the proteins related to beef tenderness at different aging times (1, 3, 7 d) and to explain the changes in the longissimus lumborum at the molecular level with ultrasound treatment. The pH value decreased significantly (p<0.05) with increasing aging time, and was lower in the ultrasonic group compared to the non-ultrasonic group. It indicated that ultrasound had a positive effect on tenderness by maintaining lower cooking loss, higher water-holding capacity (WHC), and higher myofibril fragmentation index (MFI), as demonstrated by the immunoblotting analysis of desmin and caspase-3. Twenty-eight proteins were identified as potential markers of tenderness. A PCA analysis confirmed the differential expression of tenderness-related proteins. Bioinformatics analysis suggested that these proteins, which were distributed in the cytoplasm, membrane, and mitochondria, were more likely to be impacted by ultrasound. Overall, the identified proteomics database of beef serves as a valuable reference for using ultrasound to enhance meat quality and reduce aging duration.

Changes in meat quality and muscle fiber characteristics of beef striploin (M. longissimus lumborum) with different intramuscular fat contents following freeze-thawing

Adipose (fat) tissue has different physical properties from skeletal muscle tissue, and its moisture content is relatively low; thus, freezing or freeze-thawing of meat affects its quality. However, the effect of intramuscular fat (IMF) of meat has not been comprehensively studied. The changes in the meat quality and muscle fiber characteristics of beef striploin (M. longissimus lumborum; LL) with different IMF contents (63.5 g/kg‒260.3 g/kg; n = 52) following freeze-thawing were examined. Freeze-thawing destroyed muscle fibers, and the fiber size was decreased irrespective of muscle fiber type or IMF content. However, the size of type I and IIA muscle fibers was largely altered in LL muscles with lower IMF content. Low IMF content increased the tenderness and decreased the pH of LL muscles; the effects of low IMF content on discoloration in LL muscles were less prominent. Larger IMF particles and higher density were associated with reduced thawing loss in LL muscles. IMF content reduced the lightness of frozen-thawed meat, but it did not excessively reduce water-holding capacity and pH. Thus, deterioration in meat quality can be prevented by considering the IMF content during the freezing process.

Effect of breed and sex on the body weight, slaughter traits, meat quality and meat texture parameters of rabbits

The purpose of the study was to determine the influence of breed on the growth, slaughter traits, quality traits and parameters of texture of meat obtained from Blanc de Termonde and Flemish Giant rabbits. Young animals were weaned on the 35th day of their life. The weight of animals was recorded from birth to the 84th day of life at 7-day intervals. The rabbits were slaughtered between 85th and 90th day of live. Hot carcass weight, chilled carcass weight and giblets weight (liver, lung and heart, kidneys) were recorded. The pH and the colour of the longissimus lumborum and biceps femoris muscles was measured in 45th minute and at 24 hours after slaughter. Shear force and texture parameters were measured. Flemish Giant achieve higher final body weight but lower dressing out percentage than Blanc de Termonde rabbits. Carcasses of Blanc de Termonde characterized with higher loin weight and fat content in carcass. The effect of breed fount to be significant for some components of meat colour like yellowness (b*) in 45th minute and lightness after 24 hours post mortem. The effect of sex found to be significant for acidity of meat and b* component in 45th minute after slaughter and on redness (a*) after 24 hours post mortem. Statistically significant differences between Flemish Giant and Blanc de Termonde rabbits in shear force and texture profile analysis (TPA) were stated. The sex of animals effected only on chewiness parameter for TPA of rabbit meat.

Physicochemical properties and sensory profile of some breeds of rabbits in Algeria.

The objective of this study was to compare physicochemical traits and sensory profile of meat from rabbits of both sexes belonging to two genotypes, local population and new line (ITELV 2006) which exhibited better characteristics due to its genetic potential. A total of 60 rabbits at 90 days of age were used in the experiment. At slaughter, meat physicochemical and sensory characteristics were measured on Longissimus lumborum muscle. Differences related to genotype were found in most of the physicochemical characteristics studied like Cooking Losses (P < 0.001), Percentage of Released Water (P < 0.001), Myofibril Fragmentation Index (P < 0.001) and a* value (P < 0.001). However, in some of the traits, the differences were related to interaction of sex and genotype (S*G) as in the case of Cooking Losses (P < 0.001) and b* value (P < 0.01). Regarding SDS-PAGE analysis results, the comparison between two breeds has not shown any particular distinction in the myofibrillar and sarcoplasmic protein profiles in relation to the number and the intensity of bands. No significant differences in the sensory characteristics of the meat were noted (P > 0.05). Interestingly, no relevant differences were found between meat from male and female rabbits in all the variables studied (P > 0.05). It was concluded that meat quality was mainly affected by genotype. Thus, the new line exhibited good physicochemical characteristics compared to the local one. This study is the first to analyse and compare the physicochemical and sensory properties of Algerian rabbit meat.

Effect of wet-aging on meat quality and exudate metabolome changes in different beef muscles

The aim of this study was to evaluate meat quality and changes in the meat exudate metabolome of different beef muscles (5 d postmortem, longissimus lumborum and psoas major muscles) during wet-aging (additional 3, 7, 14, 21, and 28 d of aging). Shear force of meat declined significantly (P < 0.001) with aging, meanwhile, increased myofibril fragmentation index, lipid and protein oxidation with aging were observed (P < 0.01). Psoas major (PM) showed significantly higher (P < 0.05) purge loss, centrifugal loss, and cooking loss, as well as higher tenderness and more severe lipid and protein oxidation (P < 0.01) than longissimus lumborum (LL) during aging. Principal component analysis of the metabolomic profiles revealed distinct clusters according to the period of aging and the type of muscle simultaneously. Overabundant amino acids, peptides, oxidized fatty acids, and hydroxy fatty acids were found in long-term aged meat exudates, and forty metabolites were significantly correlated with meat quality characteristics. Fifty-nine metabolites were significantly affected by muscle type. These results demonstrated the potential possibility of evaluating meat quality using meat exudate metabolomics.

Effects of three different grass silage-based total mixed rations on meat quality of finishing Holstein and Nordic Red dairy bulls

The objective of the present experiment was to study the effects of different silage-based diets on beef quality of Holstein (HO) and Nordic Red (NR) bulls. Moderate concentrate diet (MC) included grass silage (GS), barley grain and mineral-vitamin mixture in proportions of 600:385:15 on dry matter basis while the respective proportions on low concentrate diet (LC) were 850:135:15. No concentrate diet (NC) included GS, whole-crop barley silage and mineral-vitamin mixture (685:300:15). Thirty-five HO and 30 NR bulls (21–22 bulls per feeding treatment) were randomly selected for the meat quality research. One day post-slaughter, the muscle longissimus lumborum (LL) from the right side of each carcass was cut at the level of the first lumbar vertebra. The pH value of LL muscle was highest in LC, intermediate in MC and lowest in NC diet but did not differ between the breeds. For meat lightness a significant (P < 0.05) breed × diet interaction was observed. The NR bulls had lighter meat compared to the HO bulls especially with MC, but not with LC. Meat redness and yellowness were higher in MC compared to LC or NC fed bulls (P < 0.001). The breed did not affect meat redness, but yellowness was higher in HO compared to NR bulls (P < 0.05). Drip loss was higher in LL of HO than NR bulls (P < 0.01). The diets had no effects on marbling score but it was higher in NR than HO bulls (P < 0.05). Shear force was lowest in MC but no difference was found between the LC and NC and between the breeds. No differences between the treatments were found in sensory tenderness, juiciness, and flavour. Overall, the observed diet effects on meat eating quality were minor. This demonstrated the ability of finishing dairy bulls to adapt to different feedings without major effects on meat quality.

MOŻLIWOŚĆ WYKORZYSTANIA MIĘSA WIEPRZOWEGO W ŻYWIENIU PSÓW I KOTÓW

This review aims to provide an overview of the nutritional values and the possibility of pig meat (muscle longissimus lumborum) in dogs and cats nutrition based on a review of scientific literature. Pork is the most common consumed meat both in Poland and in the world. The expanding body of information concerning factors effecting impacts on pork quality was reviewed. Pork is considered valuable due to the content of high-quality proteins, fat and fatty acids, minerals, and other bioactive compounds. The content of these components depends on many factors, including breed, genetic factors, age, but also on the animal’s nutrition. The established views on pork are verified and confirmed by research that the nutritional and health-promoting value of this meat has significantly improved in recent years.

LC-MS-based metabolomics reveals metabolite dynamic changes of beef after superchilling early post-mortem

To explore the underlying mechanisms by which superchilling (SC, −3 °C within 5 h of slaughter) improves beef tenderness, an untargeted metabolomics strategy was employed. M. Longissimus lumborum (LL) muscles from twelve beef carcasses were assigned to either SC or very fast chilling (VFC, 0 °C within 5 h of slaughter) treatments, with conventional chilling (CC, 0 ∼ 4 °C until 24 h post-mortem) serving as the control (6 per group). Biochemical properties and metabolites were investigated during the early post-mortem period. The results showed that the degradation of μ-calpain and caspase 3 occurred earlier in SC treated sample, which might be attributed to the accelerated accumulation of free Ca2+. The metabolomic profiles of samples from the SC and CC treatments were clearly distinguished based on partial least squares-discriminant analysis (PLS-DA) at each time point. It is noteworthy that more IMP and 4-hydroxyproline were found in the comparison between SC and CC treatments. According to the results of metabolic pathways analysis and the correlation analysis between traits related to tenderness and metabolites with significant differences (SC vs. CC), it can be suggested that the tenderization effect of the SC treatment may be related to the alteration of arginine and proline metabolism, and purine metabolism in the early post-mortem phase.

Quality Properties and Flavor-Related Components of Beef Longissimus Lumborum Muscle from Four Korean Native Cattle Breeds.

This study was carried out to assess the quality properties, components associated with taste and aroma of beef as a function of breed. For this purpose, steers from four Korean native cattle breeds: Hanwoo (n=10), Chikso (n=10), black Hanwoo (n=12, BHW) and Jeju black cattle (n=12, JBC) were used. The steers all were raised under identical conditions and finished at a similar age of around 30-months old. Following 24 h of slaughter, all longissimus lumborum muscles were collected and used for analysis of meat quality, fatty acids, and flavor-related components (metabolic compounds, free amino acids, and aroma volatiles). The Hanwoo presented a significantly higher intramuscular fat content (IMF, 22.85%) than the BHW (11.78%), Chikso (9.25%), and JBC (9.14%; p<0.05). The meat of Hanwoo breed showed lighter and redder color, and lower shear force value (p<0.05). The JBC presented a "healthier" fatty acid profiles as it had a higher total unsaturated fatty acids content (p<0.05). With regard to flavor-related components, Hanwoo also had higher total contents of free amino acids and metabolites associated with umami and sweet tastes, and fat-derived volatile compounds (aldehydes, alcohols, and ketones) associated with fatty aroma. It may be concluded that there was a considerable difference in the meat quality properties among breeds. The variations of IMF content and flavor-related components may be the main factors contributing to the typical flavors of beef among the four Korean native cattle breeds.

Multivariate Examination of Metabolic Contributions to Beef Longissimus Lumborum Flavor

We examined the impact of muscle metabolic capacity on beef longissimus lumborum flavor. Beef carcasses were selected to have normal or dark cutting lean color (n=160, each) and aged until 13 d postmortem. Muscle pH, glycolytic potential, mitochondrial DNA copy number, instrumental lean color, myoglobin concentration, carbonyls on sarcoplasmic proteins, initial metmyoglobin formation, bloom, proximate composition, slice shear force, sarcomere length, desmin degradation, overall tenderness, juiciness, and flavor profile were determined. Carcasses were clustered based on metabolic characteristics into dark cutting classes (Control, Shady, Moderate, and Severe), which were compared using analysis of variance and multiple factor analysis. Clusters were in general, but not complete, agreement with classifications based on muscle pH. Multiple factor analysis produced 2 dimensions that explained 30.8% and 13.8% of the variation, respectively. Dimension 1 had strong negative loadings for muscle pH and strong positive loadings for glycolytic potential, L*, a*, b*, initial metmyoglobin formation, and bloom. Ratings for fat-like, overall sweet, sweet, and musty/earthy/humus had relatively weak positive loadings for dimension 1, whereas salt, sour, and metallic ratings had weak negative loadings for dimension 1. Overall tenderness and juiciness ratings, marbling score, intramuscular lipid content, carbonyls on sarcoplasmic proteins, and L* had positive loadings for dimension 2. Ratings for fat-like, beef flavor identity, and brown/roasted had positive loadings for dimension 2, and intramuscular moisture content, slice shear force, and mitochondrial copy number had negative loadings. Sample scores stratified dark cutting clusters along dimension 1, which agreed with univariate comparisons for these traits. Sample scores for dimension 2 were greater for Moderate and Control steaks than for Shady steaks. These data indicate that clustering was effective in segmenting them into groupings more indicative of the metabolic machinery than pH alone. Moreover, the semetabolic differences influenced animal variation in beef flavor profile.

Exploration of the shelf-life difference between chilled beef and pork with similar initial levels of bacterial contamination

This study compared the shelf-life of beef and pork longissimus lumborum muscles (loins) that had the same initial bacterial loads and were held under the same chilled storage conditions. To identify the underlying pathways, comparisons were conducted from the perspective of the spoilage indicators; protease/lipase activity, and the volatile organic compounds (VOC) generated over 28 d of chilled storage. The initial total viable microbial count (TVC) on Day 0 for both type of meat was 4.3 log10 CFU/g. It was found that the TVC of beef and pork did not differ throughout the total chilled storage period and both ultimately exceeded 7 log10 CFU/g after 28 d. Based on total volatile basic nitrogen (TVB-N) guidelines, pork was spoilt after 21 d of chilled storage and therefore 7 d earlier than beef. Changes in the concentration of VOC spoilage biomarkers, including 1-octen-3-ol, 1-octanol, nonanal, and others, confirmed that pork had a shorter shelf-life than beef. An important reason for the difference in shelf-life between the two types of meat was that pork had a higher protease activity, although the beef had higher levels of total lipase activity. These findings help us understand the differences in the spoilage process of raw meat from different species and explore specific measures to control the spoilage of beef or pork.

127 Color and oxidative stability of Longissimus lumborum muscles from artificially raised ram lambs finished on a high-concentrate diet

Abstract Pre-weaning strategies, such as artificially raising on milk replacer, can impact lamb quality. Limited studies have examined the influence of artificial raising on color attributes of lamb. The aim of this study was to evaluate how artificially raising on milk replacer affects the color and oxidative stability of longissimus lumborum (LL) muscle from ram lambs finished on a high-concentrate diet. For a 60-day pre-weaning period, Polypay ram lambs were reared either conventionally with ewes (CR; n = 5) or artificially on milk replacer (MR; n = 5). After 60 days, the lambs were finished on a high concentrate diet (85:15 concentrate: forage) containing 78% cracked corn and 22% pre-mixed protein pellet as the concentrate source as well as 15% orchard grass pellet as the forage source. The lambs were fed ad libitum high-concentrate diet until the target body weight of 59 kg. The lambs were harvested, and the LL muscles from both sides of the carcasses (24 h post-mortem) were fabricated into 2.5-cm thick chops. Carcass characteristics were recorded during harvesting and fabricating. The chops were placed on polystyrene trays, overwrapped with oxygen-permeable polyvinyl chloride film, and stored at 2°C in the darkness for 0, 3, and 6 d. Instrumental color, color stability (R630/580), pH, lipid oxidation, and myoglobin reducing activity of the chops were evaluated on the storage days. A split-plot design was employed to analyze the data. Pre-weaning management was the main plot, while the storage time was considered as the sub-plot. The LL muscles from each lamb carcass were considered as the experimental unit, whereas the sub-plot experimental units were the chops allocated for 0, 3, or 6 d storage. The data were analyzed using the PROC GLIMMIX. The least square means were separated utilizing the PDIFF option and adjusted with the Tukey-Kramer method. The differences among means were detected at a 5% level. There was no effect (P &amp;gt; 0.05) of pre-weaning management on carcass characteristics, surface redness (a* value), lightness (L* value), yellowness (b* value), color stability (R630/580), pH, or metmyoglobin reducing activity of LL chops. Color stability (R630/580) and metmyoglobin reducing activity declined (P &amp;lt; 0.05) during storage in both CR and MR chops. In contrast, lipid oxidation, lightness (L* value), yellowness (b* value), and hue value of the chops increased (P &amp;lt; 0.05) in both treatments during storage. Artificial raising on milk replacer for 60 d pre-weaning period did not influence color and oxidative stability of lambs finished on a high-concentrate diet. Carcass characteristics, color stability, and lipid oxidation were comparable in lambs raised through conventional method and those raised artificially on milk-replacer. These findings indicate that milk-replacer could be employed as a practical approach for artificial rearing in lamb production.

128 Impact of different levels of dark-cutting severity on the retail color and color stability of beef longissimus lumborum steaks

Abstract Dark-cutting beef is hallmarked by a dark red to almost purple color present within the interface of the ribeye between the 12th and 13th rib of the beef carcass. Yet, the shade or degree of darkness present within the ribeye can vary widely and have a substantial impact on the color and biochemical traits of the steaks. However, limited studies have compared color characteristics of different degrees of dark-cutting during retail display. Therefore, the objective of this study was to evaluate the impact of the visual degree of dark cutting at the time of grading on the retail color and color stability attributes of beef longissimus lumborum steaks. Beef strip loins (IMPS #180) were collected from two different Midwestern beef processors over the course of two collections. Strip loins (n = 8/treatment) were identified based on the degree of dark-cutting present within the ribeye to represent one-half dark, two-thirds dark, full dark, and a control of USDA Choice. At 48 to 60 h postmortem, loins were fabricated from the anterior end into 2.54 cm steaks and randomly assigned to retail display or d 0 lab analysis. Steaks designated for retail display were placed into Styrofoam trays and overwrapped with polyvinyl chloride film, and placed into retail display in coffin style display cases under continuous lighting for 5 d. Steaks designated for d 0 analysis were evaluated for pH, bloom, oxygen consumption, and metmyoglobin reducing activity. All color measurements were taken using a HunterLab MiniScan EZ spectrophotometer. The data were analyzed using the PROC GLIMMIX procedure of SAS at an α &amp;lt; 0.05. Two-thirds and full dark-cutter steaks had a greater (P &amp;lt; 0.05) pH than half and normal steaks on d 0. Moreover, full dark-cutter steaks had a decreased (P &amp;lt; 0.05) bloomed L* value and were darker in color on d 0 than normal and half steaks. Full dark-cutter steaks had a greater (P &amp;lt; 0.05) oxygen consumption and metmyoglobin reducing activity on d 0 than normal and half steaks. Full and two-third steaks had a decreased (P &amp;lt; 0.05) a* value and were less red in color on d 0 of retail display than normal and half steaks. All degrees of dark-cutters had a reduced change in redness than USDA Choice steaks. These results indicate color stability activity can be dependent on the degree of dark-cutting, with full and two-thirds dark-cutters being similar in biochemical activity.

Integrated metabolome and microbiome analysis reveals the effect of rumen-protected sulfur-containing amino acids on the meat quality of Tibetan sheep meat.

This study investigated the effects of rumen-protected sulfur-containing amino acids (RPSAA) on the rumen and jejunal microbiota as well as on the metabolites and meat quality of the longissimus lumborum (LL) in Tibetan sheep. By combining 16S rDNA sequencing with UHPLC-Q-TOF MS and Pearson correlation analysis, the relationship between gastrointestinal microbiota, muscle metabolites and meat quality was identified. The results showed that feeding RPSAA can increase the carcass weight, abdominal fat thickness (AP-2 group), and back fat thickness (AP-2 and AP-3 group) of Tibetan sheep. The water holding capacity (WHC), texture, and shear force (SF) of LL in the two groups also increased although the fatty acids content and brightness (L*) value significantly decreased in the AP-2 group. Metabolomics and correlation analysis further showed that RPSAA could significantly influence the metabolites in purine metabolism, thereby affecting L* and SF. In addition, RPSAA was beneficial for the fermentation of the rumen and jejunum. In both groups, the abundance of Prevotella 1, Lachnospiraceae NK3A20 group, Prevotella UCG-003, Lachnospiraceae ND3007 group in the rumen as well as the abundance of Eubacterium nodatum group and Mogibacterium group in the jejunum increased. In contrast, that of Turicibacter pathogens in the jejunum was reduced. The above microorganisms could regulate meat quality by regulating the metabolites (inosine, hypoxanthine, linoleic acid, palmitic acid, etc.) in purine and fatty acids metabolism. Overall, reducing the levels of crude proteins in the diet and feeding RPSAA is likely to improve the carcass quality of Tibetan sheep, with the addition of RPMET (AP-2) yielding the best edible quality, possibly due to its ability to influence the gastrointestinal microbiota to subsequently regulate muscle metabolites.