[Show abstract][Hide abstract] ABSTRACT: The effects of blade tenderization (BT), two aging methods (dry (D) and wet (W)), and aging time (2 and 23 d) on tenderness, color, and sensory properties of Longissimus lumborum muscles from 12 cull Holstein cows were evaluated. Dry-aged loins had higher combined trim and aging losses than control (C) for both D- and W-aging, mostly because of excess trim losses. BT steaks had WBSF of 33.13N while C steaks had WBSF of 41.46N (P=0.09). Aging decreased WBSF. Blade tenderized steaks had higher cook loss than C steaks. Aging, W-aging, and BT×W-aging improved myofibrillar (sensory) tenderness scores. Aging and/or BT improves sensory panel tenderness cull cow Longissimus lumborum steaks. Aging and blade tenderization combined can increase tenderness and value of Longissimus steaks from cull Holstein cows.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the effects of three aging methods: (dry (D), wet (W), and special bag (SB)); two quality grades [USDA Choice((≥Small(50) marbling) and Select); and two cooked end-point temperatures (62.8°C and 71.1°C) on physico-chemical traits of instrumental tenderness, color, and sensory properties of Longissimus lumborum beef muscle. Dry-aged loins had higher (P<0.0001) weight loss than W or SB aged loins. However, D and SB aged loins had similar (P>0.05) combined losses. W aged loins had higher (P<0.01) L* values than D or SB aged loins. Warner-Bratzler shear force of steaks was not affected (P>0.05) by aging method or quality grade but increased (P<0.0001) as end-point temperature increased. Sensory panel evaluation also showed no effect (P>0.05) of aging method or quality grade on myofibrillar tenderness, juiciness, connective tissue amount, overall tenderness or off flavor intensity. Steaks cooked to 62.8°C were juicier (P<0.05) than those cooked to 71.1°C. Neither D nor SB aging had advantages over W aging.
[Show abstract][Hide abstract] ABSTRACT: Ground beef, mixed with 0, 2, 4, and 6% Noni puree, was formed into 150-g patties, aerobically packaged, and displayed in retail for 5d. After 2 and 3d, patties with higher concentrations of Noni were perceived as redder and less discolored (P<0.05) by visual panelists. Noni patties were found to have greater (P<0.05) a* values than controls, even though all patties became less red during display. After 3 and 5d of retail display, patties with higher concentrations of Noni puree also had lower TBARS (were less oxidized; P<0.05). In fresh taste panels, panelists perceived the patties to have less beef flavor and greater incidence of off-flavors (P<0.05) as Noni puree concentration increased. The potential of Noni puree to improve the color stability and shelf life of fresh ground beef is very promising, but the flavors produced by the addition of Noni in ground beef may be detrimental to its use.
[Show abstract][Hide abstract] ABSTRACT: Twenty Bos taurus (Hereford x Angus crosses) and 20 F1 Bos indicus x Bos taurus heifers of the same age, management and feeding regimen, were harvested and evaluated at 2 days postmortem for carcass and meat traits. Ten muscles were obtained from the right sides and aged until 10 days postmortem. Bos indicus carcasses were lighter, had less fat cover, smaller ribeyes, and less intramuscular lipid (all p≤0.05). Bos taurus longissimus lumborum, gluteus medius, triceps brachii, and semimembranosus muscles cooked as steaks and roasts had a lower Warner-Bratzler shear force (WBSF) (p≤0.05) than those from Bos indicus. Bos taurus deep pectoral and semitendinosus muscles cooked as roasts had a lower WBSF (p<0.05) than Bos indicus. Infraspinatus, longissimus lumborum, and semitendinosus muscles were more tender (p<0.05) as roasts than steaks, whereas the opposite was true for the deep pectoral and semimembranosus muscles. Seven of the 10 muscles had lower WBSF (p≤0.05) for Bos taurus when cooked as steaks, roasts or both.
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT— The longissimus (modest degree of marbling) from forty beef ribs selected 48–56 hr post-mortem was used in two trials. Trial I involved A, C and E maturity ribs (10 each classification). Each rib was subjectively scored for texture (fresh) and adjacent longissimus samples were removed for the determination of protein solubility (fresh) and tenderness. Tenderness (cooked muscle) was measured with a Warner-Bratzler shear and taste panel. Protein solubilities were determined using 0.154M Krebs-Ringer-Bicarbonate buffer, 0.2M KCl + 0.01M K phosphate buffer, 1.1M Kl + 0.1M K phosphate buffer, and 0.03M K phosphate buffer. Trial II involved 10 A maturity ribs. The 0.2M KCl, 1.1M Kl and 0.03M K phosphate buffers as described for trial I were used for protein extraction. Additionally, sarcomere length was measured in formalin. Multiple regression equations were developed to predict tenderness in trial II. Protein solubilities were not significantly different between the carcass maturity groups although there were trends toward increased solubility as maturity increased. Tenderness tended to decrease from A to E maturity indicating a negative relationship between protein solubility and tenderness. Several significant negative correlations between protein solubility and tenderness were found in trial I (A maturity group) and trial II. Additionally, several significant negative correlations between texture and solubility were calculated. Correlations within the C and E maturity groups were variable and showed no definite trends. Multiple regression analyses showed that a combination of protein solubilities, texture score and sarcomere length accounted for 88% of the variation in shear force and 72% of the variation in taste panel tenderness.
[Show abstract][Hide abstract] ABSTRACT: Today's diet conscious consumers continue to desire flavorful, tender meat, but increasingly avoid excess fat. Differences in USDA quality grades within similar aged cattle are determined primarily by differences in marbling scores which tend to be associated with overall fatness in beef carcasses. Previous studies (Cundiff et al., 1988) demonstrated an antagonism between lean yield in carcasses and degree of marbling associated with higher quality grades. Breeds that rank highest for retail product percentage rank lowest for marbling. High negative genetic correlations have been found within breeds between marbling and retail product percentage. Thus, only limited opportunity exists for genetically increasing marbling without increasing fat trim and reducing retail product percentage. Nevertheless, there is a large amount of variation in palatability characteristics among animals with the same degree of marbling, suggesting the importance of factors other than marbling have a large impact on eating qualities. Concern with the antagonism between marbling and retail product percentage is justified to the extent that a certain amount of marbling is required to ensure papatability of the retail product. This report summarizes the sensory tenderness evaluations associated with marbling scores from steer carcasses produced in the Germplasm Evaluation Program at the U.S. Meat Animal Research Center
[Show abstract][Hide abstract] ABSTRACT: Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and new composite breeds and to match genetic potential with diverse markets, feed resources and climates. This report presents preliminary results from an ongoing study at the Roman L. Hruska U.S. Meat Animal Research Center (MARC)to characterize breeds of cattle representing diverse biological types for bioeconomic traits that influence quantity and value of production.
[Show abstract][Hide abstract] ABSTRACT: Variation in meat tenderness that exists among animals may be due to genetics, diet, age, and other factors. Results from the Germplasm Evaluation (GPE) program show that rib eye steaks from many of the Bos indicus breeds of cattle are less tender than steaks from most of the European (Bos taurus) breeds of cattle, although Bas indicus crossbreeding programs are advantageous due to hybrid vigor and insect and heat resistance in subtropical regions. Because consumers consider tenderness to be the principal component of cooked beef quality, it is important to determine the biological factors that regulate meat tenderness. If this knowledge can be obtained, steps could be taken to decrease the variation in meat tenderness; thus, red meat producers could consistently provide consumers with a tender product.
Factors affecting meat tenderness have been studied by MARC scientists for many years. Some factors that may affect tenderness include muscle pH (acidity), rate of temperature decline after slaughter, muscle cell length (an indicator of the state of muscle contraction), the amount of total and soluble collagen (a form of connective tissue), muscle type (red vs white muscle types), and muscle enzyme activity. Of the many enzymes found in muscle, the calpain proteolytic (enzyme) system is thought to have a major role in the meat tenderization process. These calpain enzymes occur naturally in muscle tissue as well as a specific protein, known as calpastatin, that inhibits the activity of these enzymes. Two forms of calpain exist, µ-calpain which requires low calcium concentrations for activity, and µ-calpain which requires high calcium concentrations for activity. Therefore, µ-calpain is the form that is active in muscle tissue after slaughter. During the aging or storage of meat, this enzyme system is active in degrading certain muscle proteins which must occur for meat to be tender. If the activity of this system is hindered in any way or potential for activity is lost, then tenderness is ultimately affected. Therefore, much emphasis has been placed on understanding this enzyme system.
This report summarizes results from experiments which were designed to determine which mechanisms associated with tenderness can best explain the differences or variation observed in tenderness between Bos indicus and Bos taurus breeds.
[Show abstract][Hide abstract] ABSTRACT: Decreasing the amount of fat in beef decreases loss due to trim and the number of calories in a serving. Differences in fat content of cattle are caused by differences in genotype, gender, chemical agents and energy intake relative to functional requirements. An increase in energy intake increases both fat content and body weight. Based on this fact, differences in energy intake cause an association between fat content and body weight. This fact has led some scientists to suggest the hypothesis that fat content of animals of similar genotype and gender can be predicted from body weight even if there are differences in energy intake. In order for this hypothesis to be true, rate of gain for fat must be proportional to rate of gain for body weight. Previous research has demonstrated that this is not the case. Increasing energy intake decreases the days required to reach a constant slaughter weight and increases the fat content of cattle slaughtered at a constant weight. Hence, increased fat content is associated with fewer days required to reach the same final weight when genetically similar cattle consume different amounts of energy. The contents of the gastrointestinal tract (gut fill) influences body weight. Gut fill varies among measurements of different animals or among repeated measurements of the same animal. For this reason, carcass weight is a better indicator of an animal's "true weight" than body weight. The objectives of this st4dy were to estimate differences in fat content caused by variation in energy intake and to determine the extent to which these differences are associated with carcass weight or days to slaughter.
[Show abstract][Hide abstract] ABSTRACT: Many studies have evaluated changes that occur in muscle during the aging process and how they relate to meat tenderness. Other research has shown that subjecting carcasses to higher temperatures soon after slaughter speeds the aging process that ultimately results in improved tenderness. Several things may explain this effect. The higher temperature causes the pH (acidity) of the muscle to decrease faster. Also, the combination of lower pH and higher temperature could promote an earlier release of calcium into the muscle, which normally occurs in muscle tissue after slaughter. This increase in calcium concentration in turn activates the calpain enzyme system (a naturally occurring enzyme system that is found in muscle tissue). When calpain is activated by calcium, it has the potential to degrade certain muscle proteins that must be degraded for meat to be tender. A discussion of this is found in the previous article. Therefore, because meat from Bos indicus breed crosses often is less tender than meat from Bos taurus breeds, we studied whether tenderness could be altered by carcass high-temperature conditioning and, if so, what mechanisms are involved.
[Show abstract][Hide abstract] ABSTRACT: Historically, when steers were finished on pasture, ability to finish at a young age was desirable, particularly when market requirements for fatness were great. However, ability to fatten became a handicap as we shifted to increased use of concentrate feeds in diets of growing-finishing cattle. Consequently, yield grades were added to the USDA grading system to reflect variation in carcass value associated with differences in yield of retail product. Recently, consumer pressure to reduce caloric and fat content of beef and other red meats has intensified because coronary heart disease is believed to be associated with elevated blood-cholesterol levels. Cholesterol levels are, in turn, associated with dietary intake of saturated fat. Dietary control of the type and amount of fat consumed is strongly recommended by members of the medical profession in an attempt to regulate blood-cholesterol levels. The purpose of this paper is to examine genetic variation among and within breeds in the amount and distribution of fat and lean in beef carcasses and to evaluate opportunities to genetically change fat and caloric content of retail product in cattle.
[Show abstract][Hide abstract] ABSTRACT: Implanting boar pigs at 100 lb with 24 mg of Compudose 200® (estradiol 17β) had no significant effect on "boar odor" in meat, rate of gain, feed efficiency, carcass leanness or meat quality traits. The presence of a 7 to 8 mo old gilt in the pen decreased rate of growth in both control and implanted boars, but contrary to our expectations did not increase the incidence of “boar odor". Swine Day, Manhattan, KS, November 15, 1984
[Show abstract][Hide abstract] ABSTRACT: Carcass characteristics, including composition and palatability of meat from different breeds or breed crosses, are important in determining the potential value of alternative germ plasm resources.
[Show abstract][Hide abstract] ABSTRACT: Nine Hereford x Angus (HxA), nine Simmental x Angus (SxA), and nine Limousin x Angus (LxA) crossbred steers were slaughtered in three equal groups (three from each breed) after 200, 242, and 284 days on feed to evaluate carcass chemical composition differences and their relation to growth and meat palatability.
LxA carcasses were higher in protein and retail product percentages and significantly lower in chemical fat and fat trim percentages than either SxA or HxA carcasses. SxA carcasses were superior to HxA carcasses only in having a lower percentage of fat trim.
SxA steers gained slightly faster in the feedlot than HxA and LxA steers. SxA and LxA steers were equal in weight of retail product produced per day of age and superior to HxA steers. HxA and SxA carcasses were similar in rib eye fat percentages and final quality grades, and they had higher values than LxA carcasses for these characteristics.
Correlation coefficients between carcass chemical composition and palatability traits were low and inconsistent. Correlations between carcass chemical composition and growth rate were also low and inconsistent. In addition, linear regression coefficients indicated little or no association between carcass chemical composition and growth rate or palatability.
[Show abstract][Hide abstract] ABSTRACT: Nearly all steer and heifer beef carcasses processed in the United, States are chilled before cutting. However, recent meat science research has shown that carcasses can be processed, and quality of meat maintained, with little or no chilling. Processing as defined here involves cutting the carcasses into subprimal pieces, removing bones and excess fat, sealing the pieces in vacuum packages, and placing the packages in palletized boxes. It is already known that substantial economic saving can be obtained from reduced storage and transportation costs of boxed beef, but little work has been done on the economic feasibility of hot processing.
[Show abstract][Hide abstract] ABSTRACT: What's Ahead for Cattlemen? is known as Cattlemen’s Day, 1977 Different cattle types were evaluated for growth, feed efficiency, and carcass and meat traits. Hereford (H), Angus (A), Red Poll (RP), Brown Swiss (BS), Gelbvieh (G), Maine Anjou (MA) and Chianina sires were mated artificially to Angus and Hereford cows to obtain different crossbred (X) cattle types. Two calf crops were born in March, April, and May of 1973, and 1974, and weaned when 200 days old. All male calves (787) were castrated, fed out and slaughtered in a commercial plant. Carcasses were graded in the cooler and the right side was transported to KSU for detailed cutout and meat quality evaluations.
[Show abstract][Hide abstract] ABSTRACT: SUMMARY Twelve Simmental Angus (SXA), 12 Here- ford Angus (HXA) and 12 Limousin Angus (LXA) crossbred steers fed the same finishing ration were slaughtered in three equal groups (four from each breed) after 200, 242 and 284 days on feed after weaning. After obtaining U.S.D.A. quality and yield grade data from the chilled carcass, 3.18 cm thick steaks were removed from the lO-11-12th rib locations from the right wholesale rib for taste panel, Warner-Bratzler shear and histological evalua- tion. The lean plus fat portion of the 9-10-11th rib section from the left wholesale rib was analyzed for moisture, chemical fat and pro- tein. The right side of each carcass was fabri- cated into retail product, fat trim and bone. Histological samples from the medial and lateral positions of the longissimus muscle were cryogenically frozen and stored on dry ice. Samples were later sectioned on a cryostat and stained by using myosin ATPase and DPNH diaphorase procedures. Photomicrographs were made from the stained muscle sections and fibers were classified as ~R, aW or fiR, and the number of each in a given area was counted. The size of each fiber type in selected areas was also measured. LXA crosses had more (P.05) between breeds. The LXA crosses had more (P
[Show abstract][Hide abstract] ABSTRACT: Hot processing is gaining increased interest in the beef processing industry today because of the previously mentioned processing efficiencies and economic advantages. This study examined the color and eating characteristics of electrically stimulated hot-processed beef compared with beef conventionally chilled and processed.
[Show abstract][Hide abstract] ABSTRACT: Protein supplements composed of either soybean meal, a combination of soybean meal and urea, or milo Starea improved gain 5% and feed efficiency 4% over supplements of either urea or wheat Starea (P<.25). Cost of gain favored the nonprotein nitrogen compounds; thus, choice of supplement was related to relative cost of supplements.