Performance, Feeding Behavior and Immune Response in Nellore and Angus × Nellore Steers Fed Whole Shelled Corn Diets with or without Fiber

Simple Summary

Grain diets provide a higher energy supply during the finishing phase, however, they can reduce rumen pH, leading to physiological stress in animals, affecting immune and metabolic systems and animal performance. To avoid this, an alternative is using fiber sources in low quantities. This study indicated that using fiber sources increases DMI and performance in whole shelled corn diets, and greater DMI increases haptoglobin blood concentration in low fiber diets.

Abstract

This study aimed to evaluate performance, to evaluate performance, carcass traits, feeding behavior, and humoral immune response in Nellore and Angus × Nellore steers fed whole shelled corn diets. Sixteen Nellore and 16 Angus × Nellore steers with 353 ± 25.3 kg were randomly assigned into 2 feeding groups, whole shelled corn without forage (WSC) or whole shelled corn and sugarcane bagasse (WSCB). The data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC, USA). Angus × Nellore steers had greater final BW, DMI, ADG, and subcutaneous fat thickness than Nellore. Moreover, Nellore steers had lower neutral detergent fiber (NDF) intake but spent more time ruminating and had a greater rumination rate of NDF. Regarding the diets, steers fed the WSCB had greater DMI and spent more time chewing and ruminating. Nellore × Angus steers had a greater haptoglobin concentration. The concentration of D-Lactate tended to be greater in the Nellore steers regardless of diet. In conclusion, the use of sugarcane bagasse in WSC diets increases DMI and ADG without affecting feed efficiency or the carcass traits of the steers. Although Angus × Nellore steers have increased haptoglobin concentration, this effect was not enough to reduce the performance of these animals.

Application of Ultrasound Images Texture Analysis for the Estimation of Intramuscular Fat Content in the Longissimus Thoracis Muscle of Beef Cattle after Slaughter: A Methodological Study

Simple Summary

Fat content in the muscle mass (IMF) is one of the most important characteristics influencing the aroma, tenderness, and juiciness of the meat and therefore has high importance for both commercialization purposes and consumers. However, IMF determination currently relies on visual inspection, which is a subjective and inconsistent technique. The aim of the present study is the elaboration of a procedure capable of predicting IMF% in beef carcasses using ultrasound imaging texture analysis. Ultrasound images taken on meat samples were compared to meat composition measured by chemical extraction. Determination coefficient between the two techniques was R² = 0.76, while Receiver Operating Characteristic analysis showed a sensitivity of 88% and a specificity of 90%. The results therefore suggest that the described procedure is expected to determine IMF% in muscle with good accuracy. Ultrasound imaging could be applied in routine beef grading practices. This may help to solve the issues related to subjectivity and leave to the operator only imaging acquisition. Better consistency in beef products could enhance consumers’ satisfaction and commercial standardization programs.

Abstract

Intramuscular fat (IMF) is a major trait in the evaluation of beef meat, but its determination is subjective and inconsistent and still relies on visual inspection. This research objective was a method to predict IMF% from beef meat using ultrasound (US) imaging texture analysis. US images were performed on the longissimus thoracis muscle of 27 Charolaise heifers. Cuts from the 12th to 13th ribs were scanned. The lipid content of the muscle samples was determined with the petrol ether (Randall) extraction method. A stepwise linear discriminant analysis was used to screen US texture parameters. IMF% measured by chemical extraction (IMFqa) was the dependent variable and the results of the texture analysis were the explanatory variables. The model highlighted seven parameters, as a predictive and a multiple regression equation was created. Prediction of IMF content (IMFpred) was then validated using IMFqa as ground truth. Determination coefficient between IMFqa and IMFpred was R² = 0.76, while the ROC analysis showing a sensitivity of 88% and a specificity of 90%. Bland-Altman plot upper and lower limit were +1.34 and −1.42, respectively (±1.96 SD), with a mean of −0.04. The results from the present study therefore suggest that prediction of IMF content in muscle mass by US texture analysis is possible.

Comparison of smartphone and lab-grade NIR spectrometers to measure chemical composition of lamb and beef

Context Near-infrared reflectance spectroscopy (NIRS) has been extensively investigated for non-destructive and rapid determination of pH and chemical composition of meat including water, crude protein, intramuscular fat (IMF) and stable isotopes. Smaller, cheaper NIRS sensors that connect to a smartphone could enhance the accessibility and uptake of this technology by consumers. However, the limited wavelength range of these sensors could restrict the accuracy of predictions compared with benchtop laboratory NIRS models. Aims To compare the precision and accuracy metrics of predicting pH, water, crude protein and IMF of three sample presentations and two sensors. Methods Fresh intact (FI) store-bought beef and lamb steak samples (n = 43) were ground and freeze-dried (FD), and then oven-dried to create freeze-dried oven-dried (FDOD) samples. All three forms of sample presentation (FI, FD, FDOD) were scanned using the smartphone and benchtop NIRS sensors. Key results The IMF was the best predicted trait in FD and FDOD forms by the smartphone NIRS (R2 >0.75; RPD >1.40) with limited differences between the two sensors. However, predictions on FI meat were poorer for all traits regardless of the NIRS scanner used (R2 ≤ 0.67; RPD ≤ 1.58) and not suitable for use in research or industry. Conclusion The smartphone NIRS sensor showed accuracy and precision comparable to benchtop NIRS to predict meat composition. However, these preliminary results found that neither of the two sensors reliably predicted quality attributes for industry or consumer applications. Implications Miniaturised NIRS sensors connected to smartphones could provide a practical solution to measure some meat quality attributes such as IMF, but the accuracy depends on sample presentation.

European conformation and fat scores of bovine carcasses are not good indicators of marbling

Marbling is one of the primary carcass attributes utilized in most beef grading systems for eating quality evaluation. In Europe, the current beef grading system is the EUROP grid, which is focused on carcass commercial value and production yield rather than eating quality estimation. The aim of this study was to investigate the relationship between marbling and the most common scores for carcass classification in Europe. If there are strong associations between marbling and European classification scores, marbling score may be estimated from the carcass characteristics. However, this study indicated that European classification scores explain only a slight proportion of the variance in marbling score (32%, 46%, 34% and 21% for the entire cattle group, young bulls, females and steers, respectively). Therefore, whereas the EUROP grid is well adapted to estimate yield, it does not reflect marbling at all. The European beef industry should take into account additional indicators related to beef palatability to assist the determination of the commercial value of carcasses.

Aging Condition and Retail Display Lighting Impact Retail Display Life and Lipid Oxidation of Beef Biceps Femoris Steaks

The objective of this study was to determine the impact of aging method and retail display lighting type on the discoloration and oxidation of a beef muscle with low color stability. Beef biceps femoris (BF; n = 38) were fabricated 48 h postmortem and aged for 16 d post fabrication in either wet (vacuum packaged) or dry conditions. After aging steaks (n = 9) were cut from each BF and randomly assigned to 1 of 3 retail display lengths: 1, 3, or 5 d and 3 light treatments: light emitting diode (LED), high-UV fluorescent (HFLO), or low-UV fluorescent (FLO). Steaks were removed from retail display, and were subjected to instrumental color analysis (L*, a*, b*), surface myoglobin redox forms, lipid oxidation, and metmyoglobin reducing activity. Dry aging resulted in greater (P < 0.05) redness, as determined by a*, saturation index, and hue angle values of beef BF steaks, compared to wet aging. Significant interactions (P < 0.05) between aging method and retail display day were reported for a/b ratios, hue angle, deoxymyoglobin concentrations, and lipid oxidation values. Dry aging resulted in increased (P < 0.05) lipid oxidation over the duration of retail display, as determined by thiobarbituric acid reactive substances (TBARS), in comparison to wet aging. Light by day interactions (P < 0.05) occurred for b*, metmyoglobin concentrations, oxymyoglobin concentrations, and saturation index values. Data indicate that utilization of fluorescent light sources promoted greater redness retention in a muscle with low color and oxidative stabilities over the duration of retail display in comparison to LED light sources.

Comparison of marbling fleck characteristics between beef marbling grades and its effect on sensory quality characteristics in high-marbled Hanwoo steer

The aim of this study was to compare the intramuscular fat (IMF) content and marbling fleck characteristics measured by computerized image analysis among the eight grades of Korean beef marbling standard (BMS). Additionally, this study examined the effects of the marbling fleck characteristics on objective tenderness parameters and sensory quality characteristics in high-marbled Hanwoo steers (BMS grades 7 to 9). Marked differences were observed in marbling fleck characteristics among the BMS grades (P < .05), whereas the coarseness was similar in high-marbled beef (P > .05). Due to a greater extent of coarse marbling fleck, coarse marbled steaks from high-marbled cattle were assigned higher scores of tenderness attributes, including softness, initial tenderness, and chewiness, as well as mouth coating, but were assigned lower acceptability ratings for IMF content and overall impression compared to fine marbled steaks (P < .05). Taken together, considering the marbling fleck traits can be an effective tool for improving the accuracy of beef grading systems.

Decision tree, a learning tool for the prediction of beef tenderness using rearing factors and carcass characteristics

BACKGROUND

The present study explored the potential use of decision trees on rearing factors (q = 10) and carcass characteristics (q = 12) for the development of prediction model rules of beef tenderness prediction/categorization. Accordingly, 308 young bulls were used by a sensory panel to evaluate the tenderness potential of ribeye steaks grilled at 55 °C. A classification and regression tree method was implemented and allowed the prediction of tenderness using (i) rearing factors, (ii) carcass characteristics or (iii) both.

RESULTS

The resultant tree models yielded predictive accuracies of 70.78% (with four rearing factors: concentrate percentage; fattening duration; initial body weight and dry matter intake); 67.21% (with four carcass characteristics: fatness carcass score; carcass weight; dressing percentage and muscle carcass percentage) and 84.41% (with six rearing factors and carcass characteristics) compared to the k-means clustering of tenderness. In the final and robust regression tree, from the 22 attribute information, two carcass characteristics (fatness carcass score and muscle carcass percentage) and four rearing factors (fattening duration; concentrate percentage; dry matter intake and initial body weight) were retained as predictors. The first splitter of the 308 ribeye steaks in accordance with their tenderness scores was fatness carcass score, followed by fattening duration and concentrate percentage.

CONCLUSION

The trial in the preset study highlights the importance of thresholding approach for efficiently classifying ribeye steaks in accordance with their tenderness potential. The overall prediction model rule was: IF (fatness carcass score ≥ 2.88) AND (concentrate ≥ 82%) [AND (muscle carcass ≥ 71%)] THEN meat was [very] tender. © 2018 Society of Chemical Industry.

Determination of functional and technological properties of beef based on the analysis of color digital images of muscular tissue samples

The paper considers the kinetics of changes in the values of рН and temperature of beef of slaughtered Holstein bull calfs aged 15 months during cold storage. It has been established that the rate of pH decrease during autolytic maturation is greatly influenced by the rate of temperature decrease. This was observed in the two muscles taken as an example – m. Longissimus dorsi and m. Semimembranosus. A method is suggested of analysing digital images of beef muscular tissue samples in the color coordinate space to study the beef’s color characteristics during cold storage. It has been found out that using this method, with second order polynomial fitting, provides a mean-square approximation error of 5.6% on average from the minimum coordinate of the maximum level of the red component of color. This suggests the objectivity of its use to assess the color of the meat. An analytical dependence has been established between the beef color and the term of refrigeration with the use of information technologies. In accordance with it, it has been determined that due to biochemical processes, there takes place intense oxidation of myoglobin, which results in a dark color of the muscle tissue. In the course of time (up to 120 hours of storage), the red color intensity increases. This is accompanied with decomposition of myoglobin forms that have appeared, and with appearance of МbО2. When beef is stored for more than 140 hours, deeper iron oxidation begins, with formation of methyoglobin, and the brightness of the meat decreases. The developed method allows automating registration and processing of images of muscle tissue in real time, increases the productivity of the assessment, and gives an opportunity to obtain reliable objective results about the meat properties during its storage.

Association of ADSL gene polymorphisms with meat quality and carcass traits in domestic pigeons (Columba livia)

1. Adenylosuccinate lyase (ADSL) plays an important role in the synthesis of inosine monophosphate (IMP). In this trial, a total of 200 pigeons were sampled and slaughtered. Seven meat quality traits and 11 carcass traits were measured. DNA sequencing was used to detect nucleotide mutations, and associations between ADSL gene polymorphisms and meat quality and carcass traits were analysed. 2. Sequencing results showed that 9 nucleotide mutations were found in the exons of the ADSL gene. All the mutations were synonymous except C13065G, which caused a change in amino acids (Ser to Arg). In addition, two of the detected single nucleotide polymorphisms (SNPs) had significant associations with meat quality and carcass traits. 3. For the C13065G SNP located in exon11, the IMP content of breast muscle in AA and AB genotype was higher than in the BB genotype (P < 0.01). The SNP G10696A located in exon10 was significantly associated with carcass rate, in which AA and AB genotype were higher than the BB genotype (P < 0.01). 4. The results indicated that the ADSL gene has a close association with meat quality and carcass traits in domestic pigeons, and G10696A and C13065G SNPs could be applied as genetic markers in molecular marker-assisted breeding of pigeons.

Impact of Light Source on Color and Lipid Oxidative Stabilities from a Moderately Color-Stable Beef Muscle during Retail Display

Consumers’ purchasing decisions are heavily impacted by fresh meat color, which they consider an indicator of quality in a retail setting. The objectives of this study were to evaluate the impact of light source on surface color and lipid oxidation during retail display of fresh steaks from semimembranosus (SM), a beef muscle with moderate oxidative and color stabilities. Steaks (n = 240) from the SM (n = 20) were packaged on Styrofoam trays and overwrapped with oxygen-permeable polyvinyl chloride. Steaks were then assigned to 1 of 3 lighting treatments, high UV fluorescent (HFLO), low UV fluorescent (FLO), and light emitting diode (LED) to mimic current storage conditions with a variety of industry available fluorescent bulbs, and evaluate emerging lighting conditions with LED. Steaks were removed on retail display d 1, 3, 5, and 7 for evaluation of instrumental color (L*, a*, and b* values), surface myoglobin redox forms, metmyoglobin reducing activity, and lipid oxidation. Light source influenced (P < 0.05) redness (a* values), with HFLO-displayed steaks having greatest (P < 0.05) a* values and LED-displayed steaks exhibiting lowest (P < 0.05) a* values. Surface redness decreased (P < 0.05) over retail display day. Steaks displayed in HFLO and FLO had greater (P < 0.05) oxymyoglobin percentages than those displayed under LED, indicating that LED accelerated surface discoloration compared to HFLO and FLO lights. Metmyoglobin (MMb) percentages increased over retail display, with LED-exposed steaks having greater (P < 0.05) percentages of MMb than those displayed in HFLO and FLO. By d 7 of retail display, HFLO-exposed steaks had lower (P < 0.05) MMb percentages than the steaks displayed in both FLO and LED. Lighting type did not influence (P > 0.05) lipid oxidation in SM steaks, however, lipid oxidation increased (P < 0.05) over retail display. The findings indicated that light source influenced the color stability in SM steaks during retail display and that HFLO light can minimize surface discoloration in moderate color stability beef muscles.

Associations among animal, carcass, muscle characteristics, and fresh meat color traits in Charolais cattle

This study investigated the effects of animal, carcass and muscle characteristics on initial color traits of steaks from 887 Charolais cattle. First, the fixed factors of year of birth, experiment and sex had strong impacts on color traits. From the covariates, increased age lead to intense color (low h*, -1.55 units) and darker and vivid meat (high a*, b* and C*: +4.56, +3.41 and +5.61, respectively). Increases in fatness score and carcass fat weight were associated with increases in a*, b* and C* (redness; +2.90 to +4.06 for a*; yellowness; +2.60 to +3.76 for b*; and vividness, +3.87 to +5.49 for C*) and a darker colored lean (L*; -1.56 to -3.23). As pH24h increased, a* (less red) and C* (less vivid) decreased (-3.06), whereas hue angle increased (+2.69) leading to poorer color. The selection of animals for high degree of muscularity or slaughter weight resulted in lighter and darker meat, respectively. The studied covariates could be used as indicators of Charolais beef color traits.

Repeatability and Accuracy of the Pressed Juice Percentage Method at Sorting Steaks into Juiciness Categories

The objective of this study was to evaluate the repeatability of the Pressed Juice Percentage (PJP) as well as to determine the accuracy of previously determined PJP thresholds at sorting beef strip loin steaks into categories based on the probability of being rated juicy by sensory panelists. Beef strip loin steaks representing 3 USDA quality grades (Prime, Low Choice, and Low Select) and Low Select strip loin steaks enhanced to 108% of the raw weight with a water, salt, and alkaline phosphate solution were cooked to three degrees of doneness [DOD; Rare (60°C), Medium (71°C), Very Well-Done (82°C)] to maximize variation in juiciness. Paired steaks were evaluated for PJP, Slice Shear Force (SSF), and Warner-Bratzler shear force (WBSF). Additionally, steaks representing Prime, Low Choice, and Low Select that were non-enhanced or enhanced with the same enhancement solution cooked to three DOD [Rare (60°C), Medium (71°C), Very Well-Done (82°C)] from a previously conducted sensory study were used to evaluate the ability of PJP to sort steaks into juiciness categories. Results indicated PJP had a high repeatability coefficient of 0.70, indicating only a small portion (30%) of the variation observed was due to sample measurement differences between paired samples. The repeatability of SSF and WBSF were 0.68 and 0.85, respectively. The evaluated PJP threshold values accurately segregated strip loin steaks by the probability of a sample being rated as juicy (mean juiciness rating of > 50) by consumers. The actual percentage of juicy samples was determined to be 41.67, 72.31, 89.33, and 98.08% for the predicted < 50%, 50 to 75%, 75 to 90%, and > 90% categories, respectively. Results of this study indicate the PJP juiciness measure is both repeatable and accurate in sorting beef strip loin steaks based on the likelihood of a steak being classified as juicy by consumers.

Sensory Evaluation of Enhanced Beef Strip Loin Steaks Cooked to 3 Degrees of Doneness

The objective of this study was to evaluate the impact of marbling level in combination with enhancement on beef palatability when strip loin steaks were cooked to 3 degrees of doneness. Consumer and trained sensory panelists evaluated strip steak palatability traits of 3 USDA quality grades: Prime, Low Choice, and Low Select. Additional strip loins from each grade were enhanced to 108% with a water, salt, and alkaline phosphate solution. Steaks from each treatment were cooked to 3 degrees of doneness (DOD; Rare: 60°C, Medium: 71°C, or Very Well-Done: 82°C). Consumer panelists rated all enhanced treatments similar (P > 0.05) for each palatability trait. Enhanced steaks had greater (P < 0.05) juiciness, tenderness, flavor liking, and overall liking ratings than all non-enhanced treatments, regardless of grade. Consumer juiciness, tenderness, and overall liking scores increased (P < 0.05) as DOD decreased. Trained sensory panelists rated all enhanced treatments similar (P > 0.05) for initial and sustained juiciness, myofibrillar tenderness, and overall tenderness and greater (P < 0.05) than all non-enhanced treatments, other than non-enhanced Prime, for the same traits. Trained sensory panel ratings increased (P < 0.05) as DOD decreased for sustained juiciness, and both myofibrillar and overall tenderness. Moreover, Warner-Bratzler shear force values were similar (P > 0.05) among all enhanced treatments, and lower (P < 0.05) than non-enhanced Low Choice and Low Select treatments. Results from this study indicate marbling level has no impact on the palatability traits of enhanced strip loin steaks. Therefore, enhancement of higher valued, high marbled cuts does not provide additional palatability benefits over low marbled cuts, as enhancement does not provide an additive effect with marbling on beef eating quality.

Light Source Influences Color Stability and Lipid Oxidation in Steaks from Low Color Stability Beef Triceps brachii Muscle

AbstractColor of retail fresh meat is one of the most important quality attributes affecting purchasing decisions for consumers. The objective of this study was to evaluate the impact of different light sources on surface color and lipid oxidation during retail display of fresh steaks from beef Triceps brachii (TB), a muscle with low color and lipid oxidative stabilities. Steaks (n = 12) from 20 TB muscles were overwrapped with oxygen-permeable polyvinyl chloride, and assigned to one of three lighting treatments, i.e., high UV fluorescent (HFLO), low UV fluorescent (FLO), and light emitting diode (LED), in temperature-controlled deli cases. Steaks were removed on retail display d 1, 3, 5, and 7 for evaluating instrumental color (L*, a*, and b* values), surface myoglobin redox forms, metmyoglobin reducing ability, and lipid oxidation. Surface redness (a* values) of TB steaks decreased (P < 0.05) during retail display. Light source influenced a* values, with HFLO-displayed steaks having higher (P < 0.05) a* values than steaks exposed to both FLO and LED light sources. Oxymyoglobin levels were higher (P < 0.05) for TB steaks displayed under HFLO lights than those displayed under FLO (on d 3 and 7) or LED (on d 5 and 7) lights. Steaks displayed under HFLO lights had lower (P < 0.05) metmyoglobin levels than those exposed to both FLO and LED lights on d 5 and 7. Lipid oxidation increased over retail display time, and on d 7 of retail display, steaks exposed to HFLO had less (P < 0.05) lipid oxidation than those displayed in FLO or LED. The results of the present study indicated that color stability and lipid oxidation in TB steaks during retail display are impacted by light source. The HFLO lighting may help to minimize surface discoloration and lipid oxidation in low color stability beef muscles.

Subspecies and diet affect the expression of genes involved in lipid metabolism and chemical composition of muscle in beef cattle

Fourteen Nellore and 14 Angus young bulls with BW of 381±11.8kg were randomly assigned into 2 feeding groups (whole shelled corn without forage (WSC) or corn silage and ground corn (GC)) to evaluate chemical composition and expression of genes involved in lipid metabolism in the longissimus thoracis (LT). We hypothesized that bulls fed the WSC diet have greater amounts of intramuscular fat and Angus have higher expression levels of PPAR and SREBF. Meat from Angus bulls had greater ether extract compared to Nellore (P<0.05). Muscle from bulls fed the WSC diet had greater expression of PPARA (P<0.05) and lower levels of SREBF1 expression (P<0.01). The LT of Nellore fed GC had greater expression of FABP4, ACACA and SCD genes (P<0.01). In conclusion, the greater concentration of starch in the WSC diet did not increase marbling in the beef of bulls fed this diet due to the reduced expression of SREBF1.

Determination of the effect of brand and product identification on consumer palatability ratings of ground beef patties

The objective of this study was to determine the effect of brand and product identification on consumer palatability ratings of ground beef patties. Six treatments were used in the study: 90/10 Certified Angus Beef (CAB) ground sirloin, 90/10 ground beef, 80/20 CAB ground chuck, 80/20 ground chuck, 80/20 ground beef, and 73/27 CAB ground beef. Ground beef was processed into 151.2-g patties using a patty former with 2 consecutively formed patties assigned to blind consumer testing and the following 2 assigned to informed testing. Following cooking to 74°C, patties were cut into quarters and served to consumers. Consumers ( = 112) evaluated samples in 2 rounds for tenderness, juiciness, flavor liking, texture liking, and overall liking. Each trait was also rated as either acceptable or unacceptable. In the first round of testing, samples were blind evaluated, with no information about the treatments provided to consumers, but in the second round, product type and brand were disclosed prior to sample evaluation. Additionally, texture profile and shear force analyses were performed on patties from each treatment. Few differences were observed for palatability traits during blind consumer testing; however, during informed testing, 90/10 CAB ground sirloin was rated greatest ( < 0.05) for all palatability traits other than juiciness. Also, 90/10 CAB ground sirloin had increased ( < 0.05; (consumer informed score - consumer blind score)/consumer blind score) ratings for tenderness (17.4%), juiciness (36.5%), flavor liking (23.3%), texture liking (18.2%), and overall liking (24.7%) due to brand disclosure. Increased ( < 0.05) ratings were found for CAB products for multiple traits due to treatment disclosure, whereas the only non-CAB-branded product that received increased ( < 0.05) ratings during informed testing was 90/10 ground beef for tenderness and juiciness. Texture results indicated that decreased fat level increased hardness, cohesiveness, gumminess, and chewiness. These results indicate that when sampling ground beef without brand and product information, few consumers find differences in eating quality among ground beef treatments; however, when consumers are aware of the brand, fat level, and subprimal blend prior to sampling, these factors have a large impact on consumer eating satisfaction.

RAPID COMMUNICATION: Impact of contemporary light sources on oxidation of fresh ground beef

Meat color is considered one of the driving factors in consumer purchasing decisions. The objective of this study was to determine the impact of 2 different lighting sources on color and lipid oxidation of ground beef patties in a controlled environment. USDA Select top rounds ( = 20) were processed to produce ground beef at 2 different fat levels (5 and 25%) and made into patties (113.4 g). Patties were packaged with oxygen permeable polyvinyl chloride, assigned to one of three lighting treatments (low UV fluorescent [FLO], light emitting diode [LED], and no light [DRK, negative control]), and placed within deli cases at 5°C. Patty removal for evaluation occurred on retail display d 1, 3, 5, and 7. Objective color measurements were obtained using a HunterLab MiniScan 45/0 LAV. These values were utilized to determine myoglobin redox forms as a measure of myoglobin oxidation. Additionally, thiobarbituric acid reactive substances (TBARS) were measured to indicate lipid oxidation. Objective color measurement for a* (redness), decreased for all light treatments by retail display day ( < 0.0001). Oxymyoglobin values for all light treatments decreased daily but showed no differences between treatments until d 5 ( < 0.0001) where DRK > LED > FLO. Conversely, metmyoglobin values increased daily ( < 0.0001), but showed no differences between treatments until d 5 where FLO > LED > DRK. TBARS values increased by day for each fat percentage ( < 0.0001) with 5% fat patties having higher TBARS values indicating great oxidation occurring in the phospholipids than adipose tissues. Results indicate that light treatment affected discoloration and metmyoglobin formation in ground beef patties LED lighting may lead to increased meat quality shelf life in a retail setting.

The chemical composition of carcasses can be predicted from proxy traits in finishing male beef cattle: A meta-analysis

Management practices can contribute to improving carcass quality if carcass quality could be simply evaluated under a wide range of conditions. The objective of this study was to derive quantitative relationships between the most accurate (but laborious) measurements of carcass chemical composition and proxy traits easily obtainable at slaughter (yield grade, subcutaneous fat thickness, marbling, ribeye area and hot carcass weight) by meta-analysis. Data from 34 publications using male beef cattle were used to develop and validate the models. The breeds were characterized according to origin, rate of maturity, production purpose and frame size. The results indicated that the changes in carcass fat and protein can be predicted from the yield grade or subcutaneous fat thickness, and hot carcass weight, with prediction errors ranging between 9 and 12%. Including the breed characteristics in the models did not improve the fit. The relationships are applicable to group values of male beef cattle having light and fatty carcasses from early-maturing British breeds.

Microbiological Safety of Commercial Prime Rib Preparation Methods: Thermal Inactivation of Salmonella in Mechanically Tenderized Rib Eye

Boneless beef rib eye roasts were surface inoculated on the fat side with ca. 5.7 log CFU/g of a five-strain cocktail of Salmonella for subsequent searing, cooking, and warm holding using preparation methods practiced by restaurants surveyed in a medium-size Midwestern city. A portion of the inoculated roasts was then passed once through a mechanical blade tenderizer. For both intact and nonintact roasts, searing for 15 min at 260°C resulted in reductions in Salmonella populations of ca. 0.3 to 1.3 log CFU/g. For intact (nontenderized) rib eye roasts, cooking to internal temperatures of 37.8 or 48.9°C resulted in additional reductions of ca. 3.4 log CFU/g. For tenderized (nonintact) rib eye roasts, cooking to internal temperatures of 37.8 or 48.9°C resulted in additional reductions of ca. 3.1 or 3.4 log CFU/g, respectively. Pathogen populations remained relatively unchanged for intact roasts cooked to 37.8 or 48.9°C and for nonintact roasts cooked to 48.9°C when held at 60.0°C for up to 8 h. In contrast, pathogen populations increased ca. 2.0 log CFU/g in nonintact rib eye cooked to 37.8°C when held at 60.0°C for 8 h. Thus, cooking at low temperatures and extended holding at relatively low temperatures as evaluated herein may pose a food safety risk to consumers in terms of inadequate lethality and/or subsequent outgrowth of Salmonella, especially if nonintact rib eye is used in the preparation of prime rib, if on occasion appreciable populations of Salmonella are present in or on the meat, and/or if the meat is not cooked adequately throughout.

Comparison of Carcass and Sensory Traits and Free Amino Acid Contents among Quality Grades in Loin and Rump of Korean Cattle Steer

This study was performed to compare carcass traits, sensory characteristics, physiochemical composition, and contents of nucleotides, collagen, and free amino acids among quality grades (QG) and to understand the association between QG and above parameters in loin and rump of Korean cattle steer. Loin and rump samples were obtained from 48 Korean cattle steers with each of four QG (QG 1++, 1+, 1, and 2; average 32 months of age). Carcass weight and marbling score (MS) were highest in QG 1++, whereas texture score measured by a meat grader was highest in QG 2. A correlation analysis revealed that MS (r = 0.98; p<0.01) and fat content (r = 0.73; p<0.01) had strong positive correlations with QG and that texture had a strong negative correlation (r = −0.78) with QG. Fat content in loin was highest but protein and moisture contents were lowest in QG 1++. Our results confirmed that a major determinant of QG is the MS; thus, intramuscular fat content. The International Commission on Illumination L*, a*, and b* values in loin were highest in QG 1++. Numeric values of shear force in loin were lowest in QG 1++, whereas those of tenderness, juiciness, and overall acceptability tended to be highest in QG 1++ without statistical significance. QG was strongly correlated with juiciness (r = 0.81; p<0.01) and overall acceptability (r = 0.87; p<0.001). All sensory characteristics were higher (p<0.05) in loin than those in rump. Adenosine-5′-monophosphate (AMP) and inosine-5′-monophosphate (IMP) contents in both loin and rump did not differ among QGs. No nucleotide (AMP, IMP, inosine, hypoxanthine) was correlated with any of the sensory traits. Total, soluble, and insoluble collagen contents in loin were higher in QG 1++ than those in QG 1. All three collagens had lower content in loin than that in rump. All three collagens were positively correlated with tenderness, juiciness, and overall acceptability. Glutamic acid content did not significantly differ among the four QGs in either loin or rump. In conclusion, it is confirmed that QG is associated with sensory traits but nucleotide contents in beef may not be a major factor determining meat palatability in the present study.

Beef muscle isolation has no detrimental effect on premium ground beef programs

This experiment evaluated whether isolating certain muscles from the chuck for retail sale and excluding them from ground beef mix changes the number of days that ground chuck is acceptable to consumers. Chucks were harvested from twenty-four beef steers, and were allocated to either traditional or innovative fabrication methods. Resulting ground beef patties were stored in retail simulation conditions for 7days to determine color and oxidative stability. Raw patties were analyzed for thiobarbituric acid reactive substances (TBARS), oxymyoglobin concentration, objective color by Minolta Chromameter, and by a trained sensory panel for odor, color and percent discoloration. No differences (P>0.05) were observed between traditional and innovative style patties for TBARS, sensory odor or color, or oxymyoglobin concentration. Minolta Chromameter readings revealed more substantial fading (P<0.05) in traditional patties compared with innovative style patties. This study demonstrated that removing certain muscles from the ground chuck mix does not cause detrimental consequences in resulting ground chuck patties.

Sensory evaluation of tender beef strip loin steaks of varying marbling levels and quality treatments

The palatability of tender [Warner-Bratzler shear force values <33.34N (3.4kg)] beef strip loins of 10 different treatments [USDA Prime, High Choice (upper 1/3 Choice), Low Choice (lower 1/3 Choice), Select, Standard, Australian Wagyu, American Wagyu, Holstein Select, Holstein Top Choice (upper 2/3 Choice) and Grass-finished] was evaluated by consumers and a trained flavor panel. In general, tenderness, juiciness, flavor, and overall liking ratings as well as acceptability percentage for each trait, increased with increased fat levels. Moreover, overall liking was highly correlated (P<0.01) with flavor liking (r=0.96) as well as fat percentage (r=0.79). Beef flavor scores were positively associated (P<0.01) with fat-like (r=0.67) and umami (r=0.59) flavors. Fat level was the primary driver of beef flavor acceptability in all samples when no undesirable off-flavors were present.

Importance of grass-legume choices on cattle grazing behavior, performance, and meat characteristics

We determined if tall fescue in a mixture with either tannin-containing sainfoin or saponin-containing alfalfa affected cattle foraging behavior, performance, meat quality, and consumer acceptance of meat. Foraging behavior, BW, and pasture biomass before and after grazing were monitored when cattle strip-grazed 3 replications of 2 treatments from May through September 2010 (12 calves/replication) and from June through September 2012 (8 calves/replication). Animals were allowed a choice between tall fescue and sainfoin (SAN) or tall fescue and alfalfa (ALF) growing in strips (fescue, legume, and fescue-legume mixture). Incidence of use (scan samples) of legumes increased from the beginning to the end of the trials (P < 0.05), suggesting that cattle learned to mix legumes with tall fescue. Scan samples and assessments of pasture biomass removal revealed greater use of sainfoin than alfalfa when both legumes were abundant in the spring (P < 0.05); that pattern reversed toward the end of the growing season (P < 0.05) as the abundance of sainfoin declined more than that of alfalfa. Intake of forage per kilogram of gain was greater for SAN than for ALF in 2010 (P = 0.0003) and showed a tendency to be greater for SAN than ALF in 2012 (P = 0.19). There were no differences in ADG between SAN and ALF in either year (1 kg/d; P > 0.05). No incidences of bloat were detected. When cattle (3 calves/treatment in 2010 and 8 calves/treatment in 2012) were slaughtered in September to assess meat quality and consumer acceptance, carcasses were lean (4% to 6% fat content of the longissimus muscle), but compared with ALF, SAN had higher marbling scores, quality grades (Select versus Standard), and back fat thicknesses (P < 0.05) in 2012. Steaks from cattle finished on SAN were redder in color than steaks from cattle finished on ALF (P < 0.05; 2012). Meat samples from SAN and ALF showed some differences in unsaturated fatty acid profiles and volatiles concentrations (P < 0.05), but consumer acceptance did not differ between SAN and ALF (P > 0.05). Thus, cattle incorporated a lower-quality grass into their diets even when legumes were available ad libitum during most grazing trials. Choices between tall fescue and legumes differing in the type of secondary compound (tannins vs. saponins) and bloating potential influenced patterns of forage use by cattle and led to differences in meat quality.