Lumborum Muscle Research Articles

Combined Sous-Vide and High Hydrostatic Pressure Treatment of Pork: Is the Order of Application Decisive When Using Minimal Processing Technologies?

The aim of using minimal food processing technologies is to preserve the raw material or to achieve a special technological goal with the least possible impact. When several technologies are used together, the intensity of each treatment can be reduced according to Leistner’s hurdle principle. Does the order of application of the treatments result in a detectable difference? This research focuses on the effect of the combination of the sous-vide technology and the high hydrostatic pressure (HHP) treatment. The effect of the pressure level (300 and 600 MPa) and the influence of the treatment order was investigated on pork (longissimus thoracis and lumborum muscles (LTL)). Physico-chemical and microbiological measurements were carried out on day 0 and after 21-day storage at 2 °C and 8 °C. Significant differences were found for both the order of treatment and pressure level in weight loss (p < 0.001), CIELab color parameters a* and b* (p < 0.001), and denaturation enthalpy (p < 0.01). The texture (p < 0.001) and lipid oxidation TBARS values (p < 0.05) were only influenced by the pressure level. In the challenge test, the initial count of 105 CFU/g Listeria monocytogenes dropped below detection limit in all cases. Total aerobic and anaerobic viable numbers were below/near the detection limit in all combined-treated samples on day 0 and showed only slight or more notable growth after 21-day storage at 2 °C and 8 °C, respectively. An additional 300 MPa pressure treatment can increase the safety of sous-vide cooked pork samples while having only a minor effect on physicochemical properties. The 600 MPa pressure treatment results in a stable, albeit not shelf-stable product, but it also affects a considerable number of quality parameters such as color, texture, weight loss, and TBARS values.

Using ultrasound to predict fat deposition in growing lambs of different South African sheep breed types

Subcutaneous fat (SF) and Longissimus thoracis et lumborum muscle (LM) depths of growing lambs from six breeds were monitored. Ram and ewe lambs from Dohne Merino, Dormer, Dorper, Meatmaster, South African Mutton Merino and White Dorper breeds were reared together under optimal feedlot management conditions and were subjected to ultrasound scans every fortnight from the point when the lambs attained 20 kg body weight up until 300 days of age. Exponential and linear functions were fitted to describe the change in SF depth, using body weight and age respectively, while the power curve was fitted to describe the change in LM depth. Moderate to good fits were achieved for the models describing the increase in SF depth of the various production groups with weight (R2 = 0.48–0.72) or age (R2 = 0.53–0.78) as predictor. These curves showed that hair sheep breeds are early maturing relative to wool sheep breeds, and should thus be slaughtered at lower live weights to achieve uniform levels of carcass fatness.

The impact of carcass size, chilling, and electrical stimulation on beef postmortem temperature and pH decline

Variability in carcass size can influence carcass chilling rates which could result in issues associated with beef tenderness and color. Moreover, the usage of electrical stimulation can affect postmortem metabolism and meat quality. However, few studies have looked at the combined impact of chilling and electrical stimulation on temperature decline, postmortem biochemistry, and color among the current consist of US beef. Beef carcasses (N =162, < 30 months) were randomly selected from two beef processing plants. One side of each carcass was electrically stimulated (ES), while the opposing side was not electrically stimulated (NES). Matched sides were subjected to either conventional spray chilling (CONV) or delayed-spray chilling (DELAY). Deep tissue (10.5-cm under the pelvic bone) and surface temperature (1.5-cm under the loin fat) were continuously monitored during chilling in addition to temperature and pH measurements from the semimembranosus (SM), longissimus lumborum (LL), and psoas major (PM) muscles at an initial time (45 to 60 min), 6 h, 12 h, and after chilling (28 to 36 h) postmortem. Further, the instrumental (L*, a*, and b*) and visual color of the PM were evaluated. For data analysis, carcasses with hot carcass weights above or below the average were considered heavy or light, respectively. A nonlinear regression model was fitted to the continuous deep and surface temperatures, whereas other parameters were evaluated using a mixed model. Electrical stimulation improved (P < 0.05) the color of PM in light weight carcasses, but not (P > 0.05) in heavy weight carcasses. Temperature decline was faster (P < 0.05), and pH decline slower (P < 0.05) in the SM and LL of light weight carcasses under CONV. Exponential decay models for deep and surface temperatures indicated the rate of cooling differed (P < 0.05) due to the combination of treatment factors. Heavy weight carcasses in DELAY had slower rates of temperature decline (P < 0.05). Overall, the variability in carcass size affected temperature decline and postmortem metabolism. Therefore, postmortem management practices should consider carcass weights to ensure homogeneous meat quality.

Half-castration is a newly effective method for increasing yield and tenderness of male cattle meat.

ObjectiveFor improving meat quality especially tenderness, male cattle are usually castrated to removes both the testicles. This study was conducted to evaluate the effect castration method (half- and complete-castration) on meat yield and quality characteristics of Hanwoo male cattle.MethodsThirty-two similar age (5.9 months) Hanwoo male calves were divided into: half-castration (HC) and complete-castration (CC) groups (n = 16 per group). At 7 months of age, all the animals were castrated in which the HC calves had only one testicle surgically removed while, the CC calves had both testicles surgically removed. The castrated animals were reared under identical conditions until 25 months of age. After slaughter, the carcasses were evaluated for carcass traits and meat yield of primal cuts. For examination of the castration effect on meat quality, L. lumborum and semimembranosus muscles were used. The meat samples were analyzed for chemical composition, color, pH, shear force and water holding capacity, fatty acids, metabolites and volatile aroma compounds.ResultsThe HC group showed higher meat yields of all primal cuts (p<0.05). As a result, the total meat yield was higher by approximately 44 kg in the HC group (303.32 kg, corresponding to 67.88%) compared to the CC group (259.30 kg, corresponding to 62.11%) (p< 0.05). In terms of meat quality, the HC resulted in two times greater fat content in both muscles examined compared to intact males. More importantly, the shear force values did not differ between HC and CC groups for L. lumborum muscles (p>0.05). The meat from HC animals exhibited higher amount of free amino acids associated with sweetness (p< 0.05). Furthermore, the castration method only exhibited a negligible effect on metabolites and volatile aroma compounds in the cooked meat.ConclusionHalf-castration emerged as an alternative practice to be used for increasing the yield and tenderness of male cattle meat.

Effect of Packaging Type and Aging on the Meat Quality Characteristics of Water Buffalo Bulls

Simple SummaryThe water buffalo is found worldwide, but mainly in Asian countries, i.e., India, Pakistan, and China. Buffalo meat can be a viable option to fulfill the future protein demands of the world’s population. Presently, very little information is available regarding buffalo meat quality attributes under different packaging types. Therefore, this study was designed to evaluate the effect of packaging type and aging time on the meat quality characteristics (instrumental color, WBSF, cooking loss, thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) of longissimus lumborum steaks. The results showed that vacuum packaging and aging were the most effective in decreasing the WBSF values of buffalo meat.The present study determined the effect of the packaging type and aging time on the meat quality of water buffalo (Bubalus bubalis) bulls. A total of n = 36 longissimus lumborum (LL) muscles from n = 18 buffalo bulls were obtained. Half LL muscles were packed in modified atmosphere packaging (Hi-O2 MAP), vacuum packaging (VP), and oxygen-permeable packaging (OP) on day 1, while the other half were aged for 7 days. Meat instrumental color, cooking loss, Warner–Bratzler shear force (WBSF), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) of the LL steaks were analyzed, both on unaged and aged buffalo meat. Color CIE L* and C* values on all display days and a* on the first 4 days of the simulated retail display under Hi-O2 MAP packaging were significantly higher than those of the VP and OP. WBSF and TBARS values were also higher under Hi-O2 MAP as compared to the other packaging. Steaks under OP exhibited lower cooking loss but higher TVB-N values than the MAP and VP. The 7-day-aged buffalo meat indicated higher instrumental color (L*, a* and C*), cooking loss, and lower WBSF values than fresh meat. This study concluded that Hi-O2 MAP improved the color; however, it negatively influenced the buffalo meat’s WBSF and TBAR values. Furthermore, VP and aging were the most effective in decreasing the WBSF values of buffalo meat.

Is it appropriate to use external loads during side-lying hip abduction exercise for weakened gluteus medius?

Side-lying hip abduction exercise could be beneficial to improve the neuromuscular control of the hip abductor; however, there has been limited information available to determine the exercise load during the exercise. This study aimed to demonstrate the effects of using external loads on the hip abductor muscles during side-lying hip abduction exercises in females with gluteus medius (GM) weakness. This study enrolled 24 females with weakness in the GM. Electromyographic (EMG) data of the quadratus lumborum (QL) and GM muscles were recorded during the exercise under three load conditions: no-load, external load-1 (3% of body weight), and external load-2 (5% of body weight). During the exercise, the EMG activities of the QL were significantly different under all three conditions (p< 0.05), with greater activity observed in the external load-2 condition (92.05 ± 65.93% maximal voluntary isometric contraction [MVIC]) as compared to the others, and in the external load-1 condition (82.47 ± 57.36% MVIC) as compared to the no-load condition (48.94 ± 45.09% MVIC). Furthermore, the GM/QL ratios showed significant differences between no-load (1.78 ± 1.47) and external load-1 conditions (0.93 ± 0.60), and between no-load and external load-2 (0.85 ± 0.45) conditions (p< 0.05). These findings suggest that greater load could be a factor to increase the QL activity during the exercise in females with weakened GM.

Effect of dietary restriction and compensatory growth on performance, carcass characteristics, and metabolic hormone concentrations in Angus and Belgian Blue steers

Compensatory growth (CG) is the ability of an animal to undergo accelerated growth after a period of restricted feeding. However, there is a dearth of information in relation to the effect of genotype on CG response, thus the objective of this study was to evaluate CG response in two contrasting breed types, namely Aberdeen Angus (AN) and Belgian Blue (BB). Crossbred AN × Holstein-Friesian or BB × Holstein-Friesian steers were assigned to one of two treatment groups in a two (genotypes) × two (diets) factorial design. For 99 days, one group (11 AN and 12 BB) was offered a high energy control diet (H-H) whereas the second group (11 AN and 12 BB) was offered an energy restricted diet (L-H). At the end of the differential feeding period (99 days), both groups of animals were then offered a high energy control diet for a further 200 days. All animals were then slaughtered on day-299 of the study. During feed restriction, L-H had lower DM intake (DMI), had greater feed conversion ratio (FCR) and lower plasma concentrations of insulin, IGF-1, leptin, glucose, urea, betahydroxybutyrate and smaller M. longissimus thoracis or lumborum muscle and fat depths compared to H-H steers. During realimentation, there was no difference in DMI between diets; however, L-H had greater live weight gain compared to H-H steers. Overall, H-H consumed greater quantities on a DM basis, however, had a higher FCR compared to L-H steers. By the end of the realimentation period, there was no difference in plasma metabolite or hormone concentrations, linear body measurements, ultrasonically scanned fat depths, carcass conformation, dressing percentage or fat class between H-H and L-H steers. At slaughter, carcass weights were affected by diet with greater values for H-H compared to L-H steers. Genotype affected measures associated with body composition including pelvic width and both muscle and fat depths (P < 0.05). Overall, L-H had a CG (or recovery) index of 0.52 and did not make up for the loss of gains during the differential feeding period; however, M. longissimus thoracis et lumborum, a tissue of high economic value, recovered completely making it a target of interest for further investigation.

Muscle and Subcutaneous Fatty Acid Composition and the Evaluation of Ageing Time on Meat Quality Parameters of Hispano-Bretón Horse Breed.

Simple SummaryHorse meat; even though is still not popular in most countries; its consumption is slowly increasing and has the potential to become an alternative future red meat. However; research is still insufficient and a deeper understanding of its nutritional and physicochemical characteristics would be beneficial for the horse meat industry. The capacity of horses to efficiently uptake polyunsaturated fatty acids into their tissues has been reported; but detailed knowledge about horse meat fatty acid composition is limited. The present work provides a comprehensive fatty acid composition analysis of subcutaneous and muscle tissues from semiextensively reared Hispano-Breton horses; results indicated that finishing on a high-grain diet limited muscle n-3 accumulation. In addition; the evolution of physicochemical quality parameters such as pH, instrumental color, texture and cook loss were thoroughly studied during vacuum ageing (0, 7, 14 and 21 days), and the conclusion was that an ageing period between 7 and 14 days would be recommended for an optimum horse meat quality. The reasons for this recommendation were that tenderness increased during the first two weeks and then stayed stable and that visual properties deteriorated after 14 days. Overall; these results will help to standardize post mortem practices to obtain a homogeneous final horse meat quality.A full-randomized block design was used for the study of the FA composition and meat quality parameters, considering ageing time as a split-plot factor. Chemical and fatty acid composition of steaks (longissimus thoracis and lumborum muscle) from 15 month old semiextensively reared Hispano-Bretón horses were characterized (day 0), and the effect of vacuum ageing (0, 7, 14 and 21 days) on several meat quality parameters (pH, instrumental color and texture and cook loss) was determined. The average fat content of horse loin was 3.31%, and the n-3 polyunsaturated fatty acid content, although higher than in ruminant meats, suggested that the finishing on a high-grain diet limited muscle n-3 accumulation. Results revealed that ageing affected all meat quality measurements; color started to turn brownish at 14 days of ageing, with a decrease in redness but not in yellowness. Tenderness improved during the first two weeks, and the Warner-Bratzler shear force scores showed that meat aged for 7 days could be considered as ‘intermediate tender’. Under the present study conditions, an ageing period between 7 and 14 days is recommended for an optimum horse meat quality.

The influence of muscle, ageing and thermal treatment method on the quality of cooked beef

The study was undertaken to investigate the effect of muscle, thermal treatment, and ageing on the beef quality. The longissimus lumborum (LL) and semimembranosus (SM) muscles were taken from Holstein–Friesian young bull carcasses then subjected to steam-cooking and sous-vide after 9 and 14-d wet ageing. It was shown that characteristics of cooked beef were the most significantly affected by thermal treatment method. Using sous-vide provided beef with lower shear force and cooking loss values, darker, and more red colour and more beneficial sensory quality. LL and SM muscles showed a similar quality when subjected to the same thermal treatment method after the same ageing time. It is possible to obtain juicy and tender beef from Holstein–Friesian bulls after 9-d ageing and sous-vide treatment.

Effect of Passive Support of the Spinal Muscles on the Biomechanics of a Lumbar Finite Element Model

Finite element (FE) modeling of the passive ligamentous spine is widely used to assess various biomechanical behaviors. Currently, FE models that incorporate the vertebrae, ligaments, and the personalized geometry of the bony spine may be used in conjunction with external loads from the muscles. However, while the muscles place a load (moment) on the spine and support it simultaneously, the effect of the passive support from the adjacent spinal muscles has not been considered. This study thus aims to investigate the effect of passive support from the psoas major, quadratus lumborum, and erector muscles on the range of motion (RoM) and intradiscal pressure (IDP) of the lumbar spine. Various L2-sacrum spinal models that differed only in their muscle properties were constructed and loaded with a pure moment (2.5–15.0 Nm) alone or combined with a compressive (440 or 1000 N) follower load. The RoM and IDP of the model that excluded the effect of muscles closely matched previous FE results under the corresponding load conditions. When the muscles (40–160 kPa) were included in the FE model, the RoM at L2 was reduced by up to 6.57% under a pure moment (10 Nm). The IDP was reduced by up to 6.45% under flexion and 6.84% under extension. It was also found that the erector muscles had a greater effect than the psoas major and quadratus muscles.

Impact of milk thistle (Silybum marianum L.) seeds in fattener diets on pig performance and carcass traits and fatty acid profile and cholesterol of meat, backfat and liver

The aim of this study was to determine the effect of milk thistle seed supplementation in pig fattener diets on productive traits, slaughter carcass traits, and meat quality as well as meat, backfat and liver fatty acid composition. The experiment was carried out using 60 barrows, with an initial body weight of 25.0 ± 0.5 kg. The experiment lasted for 100 days. The animals were divided into 3 groups, with 20 pigs in each. The diet of the control group (group I) did not have thistle supplementation, while the remaining groups received 3% (group II) or 6% (group III) thistle in the mixture. Analysis showed that the milk thistle seeds contained relatively high contents of protein, fat, lysine, linoleic acid, oleic acid, and active flavonolignans – specifically silybin A and B (26.4 g), isosilybin (5.3 g), silychristin (10.6 g) and a low amount of silydianin (0.1 g). The 3% milk thistle seed addition improved the average daily weight gains by about 2% and 6% addition improved the gains by 3.8% during the grower period. There was no significant effect of milk thistle seeds on carcass meat content but the backfat layer was thinner. The meat of pigs which received milk thistle was more saturated in red (significantly higher a* values) and less saturated in yellow (significantly lower b* values) for both fresh and cooked samples and its texture, water-holding capacity and oxidative capacity were all improved (thiobarbituric acid reactive substances (TBARS) index lower by more than 30%). The addition of milk thistle seeds decreased the cholesterol content in lumborum muscle, backfat and liver, and these tissues were also characterised by higher polyunsaturated fat (PUFA) content and lower PUFA n-6 : n-3 ratio. Milk thistle seeds increased the hypocholesterolemic : hypercholesterolemic (h : H) index in all tissues and reduced the thrombogenic (TI) and atherogenic (AI) indices. Summing up the results, milk thistle seeds at supplementation levels of 3 and 6% are indicated to be a useful feed admixture for fattened pigs to improve meat quality and oxidative stability. The higher dose of milk thistle seeds (6%) appeared to be more effective in improving weight gains, feed utilisation, PUFA content in tissues, and water-holding and antioxidant capacities.

Utilization of Bioelectrical Impedance to Predict Intramuscular Fat and Physicochemical Traits of the Beef Longissimus Thoracis et Lumborum Muscle.

The bioelectrical impedance analysis (BIA) is a non-destructive technique that has been successfully used to assess the body and carcass composition of farm species. This study aimed to predict intramuscular fat (IMF) and physicochemical traits in the longissimus thoracis et lumborum muscle (LM) of beef, using BIA. These traits were evaluated in LM samples of 52 crossbred heifer carcasses. The BIA was performed in LM, using a 50 Hz frequency high precision impedance converter system. A correlation analysis of the studied variables was performed. Then a stepwise with a k-folds cross validation procedure was used to modelling the prediction of IMF and physicochemical traits from BIA parameters (24.5% ≤ CV ≤ 47.3%). Wide variation was found for IMF and BIA parameters. In general, correlations of BIA parameters with IMF and physicochemical traits were moderate to high and were similar for all BIA parameters (−0.50 ≤ r ≤ 0.50 only for total pigments, a* and pH48). It was possible to predict IMF and physicochemical traits from BIA. The best fit explained 79.3% of the variation in IMF, while for physicochemical traits the best fits were for sarcomere length and shear force (64.4% and 60.5%, respectively). The results confirmed the potential of BIA for objective measurement of meat quality.

Age-specific differences in the time-frequency representation of surface electromyographic data recorded during a submaximal cyclic back extension exercise: a promising biomarker to detect early signs of sarcopenia

PurposeMotivated by the goal of developing new methods to detect early signs of sarcopenia, we investigated if surface electromyographic (SEMG) data recorded during the performance of cyclic, submaximal back extensions are marked by age-specific differences in their time and frequency characteristics. Furthermore, day-to-day retest reliability of the EMG measures was examined.MethodsA total of 86 healthy volunteers used a back dynamometer to perform a series of three maximal voluntary contractions (MVC) consisting of isometric back extensions, followed by an isometric back extension at 80% MVC, and finally 25 slow cyclic back extensions at 50% MVC. SEMG data was recorded bilaterally at L1, L2, and L5 from the iliocostalis lumborum, longissimus, and multifidus muscles, respectively. Tests were repeated two days and six weeks later. A linear mixed-effects model with fixed effects “age, sex, test number” and the random effect “person” was performed to investigate age-specific differences in both the initial value and the time-course (as defined by the slope of the regression line) of the root mean square (RMS-SEMG) values and instantaneous median frequency (IMDF-SEMG) values calculated separately for the shortening and lengthening phases of the exercise cycles. Generalizability Theory was used to examine reliability of the EMG measures.ResultsBack extensor strength was comparable in younger and older adults. The initial value of RMS-SEMG and IMDF-SEMG as well as the RMS-SEMG time-course did not significantly differ between the two age groups. Conversely, the IMDF-SEMG time-course showed more rapid changes in younger than in older individuals. Absolute and relative reliability of the SEMG time-frequency representations were comparable in older and younger individuals with good to excellent relative reliability but variable absolute reliability levels.ConclusionsThe IMDF-SEMG time-course derived from submaximal, cyclic back extension exercises performed at moderate effort showed significant differences in younger vs. older adults even though back extension strength was found to be comparable in the two age groups. We conclude that the SEMG method proposed in this study has great potential to be used as a biomarker to detect early signs of sarcopenic back muscle function.

The effects of pressure biofeedback on hip and trunk muscle activity and lumbopelvic alignment during one-leg standing

BACKGROUND: During one-leg standing (OLS), optimum activity of the gluteus medius (Gmed), multifidus (MF), and quadratus lumborum (QL) muscles relies upon maintaining neutral lumbopelvic alignment. However, no studies have examined how using pressure biofeedback during OLS affects the activity of these muscles and the concomitant alignment of the pelvis and trunk. OBJECTIVES: The purpose of this study was to investigate the effect of pressure biofeedback on the activity of the Gmed, MF, and QL and the femoropelvic and trunk lean angles during OLS. METHODS: Twenty-four healthy males performed OLS with (PB+) and without (PB-) pressure biofeedback. For all OLS conditions, a pressure sensor was placed between the lateral surface of the humerus on the non-supporting side and the wall. Under the PB- condition, participants performed preferred OLS while the examiner measured the maximum pressure caused by trunk lean. Under the PB+ condition, participants were asked to perform at a threshold of 50% of the maximal pressure (PB+ 1 condition) and with minimal change in pressure (PB+ 2 condition). Muscle activities of MF, QL, and Gmed as well as the femoropelvic and trunk lean angles were measured under various OLS conditions. RESULTS: The activity of the Gmed, MF, and QL was greater under both PB+ conditions than under the PB- condition (p&lt; 0.05). Also, both PB+ conditions resulted in a greater femoropelvic angle and reduced trunk lean angle. There were no significant differences in muscle activity, femoropelvic angle, or trunk lean angle between PB+ 1 and PB+ 2 (p&gt; 0.05). CONCLUSIONS: These results suggest that pressure biofeedback is a useful modality for increasing the activity of the Gmed and trunk muscles, especially the MF muscle on the non-supporting leg side, and for preventing compensatory movements such as trunk deviation and pelvic lateral deviation during OLS.

Effects of soybean meal versus processed whole soybean diets on the performance of young bulls and the fatty acid composition of intramuscular fat

Context It is hypothesised that the use of processed soybean for feedlot beef cattle improves feed efficiency and produces beef with a better fatty acid profile for human health. Aims This study aimed to evaluate average daily gain, feed efficiency, carcass traits, chemical composition, fatty acid profile and colour in the beef of young bulls fed diets with ground or extruded soybean. Methods A total of 60 young Zebu bulls (Nellore or Nellore crossed with other Zebu breeds) with an average initial liveweight of 320 ± 8.12 kg and an average initial age of 20 ± 2 months were randomly assigned to receive one of the following diets for 84 days: dehulled and defatted soybean meal (3.22% of ether extract), ground soybean (6.51% of ether extract) or extruded soybean (6.37% of ether extract). The fatty acid profiles of these animals were analysed using high-resolution gas chromatography. The CIE L*a*b* colour space model was used to numerically describe the colour during the aging period (0, 7, 14 and 21 days). Key results Diet had no effect on the average daily gain, feed efficiency or carcass traits of the animals (P &amp;gt; 0.05). Protein, ether extract and ash composition of the Longissimus lumborum (LL) muscle were not affected (P &amp;gt; 0.30) by the use of processed soybean grains. The ground soybean diet decreased oleic acid and C18:2 c9, t11 concentrations, but increased C18:2 t10, c12 and trans-octadecenoic acid isomer concentrations in the LL muscle compared with those in the dehulled and defatted soybean meal and extruded soybean diets (P &amp;lt; 0.05). Muscle from bulls fed processed soybean exhibited greater concentrations of stearic acid and saturated fatty acids, and a lower concentration of unsaturated fatty acids, as well as a decreased unsaturated fatty acids:saturated fatty acids ratio (P &amp;lt; 0.05). Processed soybean grains did not affect (P &amp;gt; 0.05) the LL muscle pH or colour. Conclusions The use of ground or extruded soybean did not affect the performance, carcass traits, LL protein, ether extract or ash composition, and had no impact on beef colour compared with the diet containing soybean meal. Processed whole soybeans in the diet did not increase unsaturated fatty acids or conjugated linoleic acid in beef compared with a diet without soybean meal. Implications Up to 20% of ground or extruded soybean in feedlot beef cattle can be used as a replacement for soybean meal and corn.

Meat Quality, Aroma Profile and Consumer Preference of Dry-Aged Beef

ObjectivesAging is a method for improving some sensory characteristics of meat, enhancing flavor and tenderness. The effect of aging in tenderness is well known but not well established in the flavor of dry-aged beef. This study aimed to evaluate the meat quality, volatile compounds profile and consumer preference between fresh and dry aged beef.Materials and MethodsLongissimus thoracis and lumborum muscles (right side) from five steers of Canchim (5/8 Charolais × 3/8 Zebu) breed fed with the same pellet diet (25% peanut shell; 69.23% corn grain; 2.27% soybean meal; 1% sodium bicarbonate; 1.50% minerals; 1.00% urea and 0.03% monensine in dry matter) were used. Animals were slaughtered at 36 mo of age with 562 kg of average weight. After 24 h postmortem, from the muscles of approximately 30 cm length, half of each was deboned, cut into 2.5 cm width steaks (“fresh”). The other half, which were bone-in beef loins, were maintained at 1 ± 1°C and 70% relative humidity (“dry-aged”) in a refrigerated chamber for 28 d, deboned and trimmed. Fresh and dry-aged samples were analyzed for meat quality (color, pH, water holding capacity, cooking loss, and Warner-Bratzler shear force). The remainder of these samples were vacuum packaged and frozen for sensory and volatile compounds analyses. Volatile compounds extracted by Solid-phase microextraction technique (SPME) were analyzed by Gas Chromatography/Mass Spectrometry (GC–MS). Consumer paired preference was performed in two sessions, where the preferred sample should be chosen and analyzed by using a table Standard Test Method for Directional Difference Test (ASTM E2164-08). Meat quality and volatile compounds results were analyzed by t test.ResultsColor, pH, and shear force were significantly different (p &lt; 0.05) between fresh and dry aged samples. Higher values (p &lt; 0.05) of a* (20.6) and b* (16.8) parameters were found in the dry aged meat meaning greater red color intensity in the dry aged samples. Fresh samples showed the lowest values (5.45). The shear force values were lower (p &lt; 0.05) for dry aged samples (3.60 kgf) if compared to fresh samples (7.9 kgf). A total of 58 volatile compounds were found in fresh and dry aging meat: 13 hydrocarbons (22.4%), 12 aldehydes (20.7%), 9 ketones (15.5%), 8 alcohol (13.8%), 6 aromatic compounds (10.3%), carboxylic acid (8.6%), 3 sulfur compounds (5.2%), 1 lactone (1.7%) and 1 pyrazine (1.7%). Thirty-nine compounds were common to both treatments being 37 of them with odoriferous importance. Only 3 compounds (2-ethyl, 1-hexanol, 3-ethyl-3-hexene, and octane) were found only in fresh meat. Thirteen compounds were found only in the dry aged meat samples, being the main ones of odoriferous importance: methional (cheddar cheese), heptanoic acid (cheese), 2, 3-butanediol (cocoa butter), dimethyl disulfide (kale), furan, tetrahydro-2-methyl- (roasted, crusted beef and chicken), butanoic acid (rancid), dimethyl trisulfide (sulfureous, grassy) and 3-Octanone (musty, mushroom, moldy and fermented cheese). In the paired preference test, 71 from 78 consumers preferred the dry aged sample, mentioning mainly the reason for the choice the tenderness and flavor.ConclusionDry-aged beef showed enhanced tenderness and red color compared to fresh beef. Many volatile compounds of odoriferous importance were found in the dry aged beef which contributes to its unique flavor, explaining why it was more preferred in this study.

Comparison of Lipid and Protein Oxidation Products and their Impact on Colour Stability in Bison Longissimus Lumborum and Psoas Major Muscles

ObjectivesTo compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products and determine their influence on color stability in two bison muscles (longissimus lumborum [LL; color stable] and psoas major [PM; color labile]).Materials and MethodsA total of 10 longissimus lumborun (LL) and 10 psoas major (PM) from five A1 grade bison carcasses were obtained from a commercial slaughter plant within 48 h post-mortem. From each muscle, a 10-cm thick piece was removed and subsampled for evaluation of pH, MDA (by thiobarbituric acid assay), HNE (by ELISA) and CAR (by 2,4-dinitrophenylhydrazine). These measurements allowed the establishment of a baseline for the different oxidation products. The remainder of the muscles were cut into two equal portions, and each portion was vacuum-packaged and assigned to an ageing period of 7 and 14 d at 2°C. At the end of each ageing period, each muscle portion was removed from their packages, pH measured, and steaks obtained for sensory (muscle and discoloration scores) and instrumental color measurements (L*, a* and b*) over 5 d of retail display, and for estimation of MDA, HNE and CAR. After 5 d in retail display and following color and pH measurements the steaks were removed and collected for MDA, HNE and CAR determination. Data were analyzed as a completely randomized design with a split-split plot arrangement. Additionally, correlation and regression analysis were performed to identify the influence of the measured attributes on color.ResultsRegardless of the ageing time, LL showed greater redness and lower surface discoloration by instrumental (a* value; P = 0.04) and sensory (P &lt; 0.01) color evaluation than PM at the end of the retail display. Furthermore, LL exhibited lower MDA, HNE and CAR content compared to PM (P &lt; 0.05). A three-way interaction (muscle × ageing time × retail day display) was detected on MDA content, where PM presented a higher level of MDA with increasing ageing time and retail display than LL (P = 0.02). The pH was not different between LL and PM (P &gt; 0.05) steaks.In both muscles, Pearson (r) and Spearman (rs) correlation coefficients indicated that MDA was the oxidation compound showing the highest correlation to a* (r = –0.78; P &lt; 0.01) and discoloration (rs = 0.81; P &lt; 0.01) scores, followed by a moderate correlation with HNE and CAR (r or rs &lt; 0.7; P &lt; 0.01). The pH did not exhibit correlation with color traits, except for lightness, in both muscles. For the stepwise regression analysis, the main variable entered into the equation for predicting a*, color and discoloration score in PM muscle was MDA with an R2 of 0.72, 0.75 and 0.78, respectively, while for LL muscle, MDA presented an R2 of 0.62, 0.68 and 0.66;, respectively. The pH, HNE and CAR only explained an additional 2% of the variation in those attributes.ConclusionThe results of color attributes corroborated that bison LL is a color-stable muscle due to the lower level of protein and lipid oxidation products developed during storage and retail display compared to PM muscle, which is considered color-labile muscle. The MDA seemed to have remarkable importance in the color deterioration than HNE and CAR, particularly in bison PM muscle.

Tandem Mass Tag Labeling to Identify Proteome Changes in Beef Longissimus Lumborum and Psoas Major Muscles During Early Postmortem Period

ObjectivesLongissimus lumborum (LL) and psoas major (PM) are important muscles in beef hindquarters that exhibit variation in meat quality attributes. Postmortem metabolism (muscle-to-meat conversion) affects biochemical properties of muscles and in turn influence the meat quality. Although previous research has indicated that variation in the proteome profile of LL and PM post-rigor influences meat quality attributes such as tenderness and color stability during retail display, limited research has examined the influence of early postmortem metabolism on meat quality. Tandem mass tag (TMT) labeling is a chemical labeling approach used for accurate mass spectrometry-based quantification and identification of biological macromolecules. Therefore, the objective of this study was to use TMT labeling to examine proteome profile variation between beef LL and PM during the early postmortem period.Materials and MethodsMuscle biopsy samples were collected from carcasses (n = 4) at 45 min, 12 h, and 36 h postmortem from a commercial beef processing facility. Samples were frozen immediately in liquid nitrogen and stored at –80°C until proteomic analysis. Proteome was analyzed using TMT label containing ten different isobaric compounds with the same mass and chemical structure composed of an amine-reactive NHS-ester group, a spacer arm, and a mass reporter. After labeling and peptide fractionation, all the samples were multiplexed and ran through the Orbitrap Velos mass spectrometer equipped with a Nanospray Flex ion source to identify differentially abundant proteins. The proteins exhibiting 1.5-fold or more intensity difference and a statistical difference (P &lt; 0.05) between LL and PM or within the muscles during the postmortem were reported as differentially abundant.ResultsSeventy differentially abundant proteins (P &lt; 0.05) were identified from three comparisons between the muscles (31 proteins in PM 45 min vs. LL 45 min, 41 proteins in PM 12 h vs. LL 12 h, 49 proteins in PM 36 h vs. LL 36 h). However, no difference (P &gt; 0.05) in protein expression within a muscle was observed during these time points. The differentially abundant proteins were mainly involved in oxidative phosphorylation and ATP-related transport, tricarboxylic acid cycle, NADPH regeneration, fatty acid degradation, muscle contraction, calcium signaling, chaperone activity, oxygen transport, as well as degradation of the extracellular matrix. At early postmortem, overabundant anti-apoptotic proteins in LL could cause high metabolic stability, enhanced autophagy, and delayed apoptosis, while overabundant metabolic enzymes and pro-apoptotic proteins in PM could accelerate the reactive oxygen species generation and programmed cell death.ConclusionDifferentially abundant proteins between LL and PM during the early postmortem were primarily associated with cellular metabolism and programmed cell death. The greater oxidative and color stability in LL compared to PM could be related to the increased expression of anti-apoptotic proteins and the decreased expression of metabolic enzymes and proapoptotic proteins in LL.

The effect of Goji berries (Lycium barbarum) dietary supplementation on rabbit meat quality

This study evaluated the effect of different dietary concentrations of Goji berries (GB) on the meat quality of rabbit. At weaning, 60 New Zealand male rabbits were assigned to three groups and fed with a commercial standard diet (C), C supplemented with 1% (LG) or 3% Goji berries (HG) until slaughter. Supplementation did not affect colour, water holding capacity, and tenderness but regression analyses showed linear relationships between pH (P < .05), Thiobarbituric Acid Reactive Substances (TBARS; P < .001), Oxygen Radical Absorbance Capacity (ORAC; P < .001), Redox Index (RI; P < .001), and phenolic content (P < .001) of Longissimus thoracis et lumborum muscle and the rate of GB in the feed. However, by pairwise comparisons emerged that acidification (pH: P < .05), antioxidant/oxidant status (TBARS, ORAC, RI; P < .001), and phenolic content (P < .01) of muscle significantly improved only in HG compared with C group. Then, a dose-dependent relation was found but only the higher dose of GB guaranteed an increase in protection against oxidative phenomena of meat.

Effects of corn supplementation on meat quality and fatty acid composition of Dorper lambs fed PKC-Urea treated rice straw

BackgroundThe increasing costs of feed has subsequently increased the costs of production of livestock, thereby decreasing the profit margin of this sector. The utilization of agro-industrial by-products has to some extent substitute some of the corn grains and soyabean meal, commonly used in animal feeds. In Malaysia, palm kernel cake (PKC) is a by-product of the oil palm industry and is frequently used to supply both crude protein (14–16% CP) and energy (11 MJ/kg) in ruminants. The energy and protein content are adequate for maintenance in the majority of ruminants. However, highly available energy supplementation is known to improve growth performance and protein deposition. This study was carried out to determine the effect on the quality of meat and fatty acid composition of the semitendinosus (ST), supraspinatus (SS), and longissimus lumborum (LL) muscles of Dorper lambs by including corn as an energy source in a basal diet of PKC urea-treated rice straw.ResultsThe results show that the LL muscle-drip loss was greater in animals supplemented with 5% corn compared to the other groups. Higher pH values of SS and LL muscles were observed in animals supplemented with 5 and 10% corn. Furthermore, the L* value of ST muscle was increased in lambs fed on 5% corn while, reduced in those fed on 0% corn, but the a* and b* values were not significantly different in the treatment groups. The fatty acid composition of the SS muscles showed that lambs fed on 10% corn had higher levels of sum PUFA n-3 compared to those fed on 0% corn. The concentration of C18:1trans11 and CLA c12 t10 in ST muscle from the lambs fed on supplemented diets were higher than those of the controls.ConclusionThis study has concluded the supplementation of corn as a source of energy into a PKC urea-treated rice straw-based diet increased the PUFA concentrations of muscles as compared to control groups.