Rib Steaks Research Articles

Topical Application of Acerola Cherry Powder in Combination With Rosemary Extract Extends the Shelf Life of Beef Chuck Roll and Bone-In Short Rib Steaks

Improving the shelf life of steaks from beef chuck rolls and bone-in short ribs, items commonly exported, will increase the demand of beef in international markets. Our objectives were to determine the effect of topically applying combinations of acerola cherry powder and rosemary extract on steak color and lipid oxidation of beef chuck roll and bone-in short rib. USDA Choice beef chuck rolls (Institutional Meat Purchase Specifications [IMPS] 116A; N=9) andbone-in short ribs (IMPS 123A; N=18) were aged (0°C) 28 d and cut into 1.0 cm-thick steaks. Steak treatments included the following: untreated control (C) or topically sprayed (2 mL) with an acerola cherry powder solution (0.05% A), rosemary extract solution (0.10% R), or mixture of acerola cherry powder and rosemary extract (M1=0.05% A+0.1% R; M2=0.1% A+0.1% R; M3=0.05% A+0.2% R; M4=0.1% A+0.2% R). On day 0 of retail display, oxygen consumption, metmyoglobin-reducing activity, and lipid oxidation were measured. Lipid oxidation was evaluated again following 4 d of retail display. Chuck roll steak color was scored twice daily, whereas short rib lean and bone marrow color were scored once daily throughout 4 d of retail display. Treating chuck roll steaks with M2, M3, and M4 decreased lipid oxidation compared to C and A (P=0.004). In short rib steaks, lipid oxidation remained constant from day 0 to 4 treated with M4 but increased for all other treatments (P<0.001). Chuck roll steaks treated with A, M2, and M3 were redder than C steaks (P=0.001). On days 0 and 4, untreated bone marrow was less red than all the antioxidant treated bone marrow (P=0.011). Antioxidant treatment did not improve subjective lean color for the chuck roll (P=0.324) or bone-in short rib (P=0.081). Topical application of M4 (0.1% acerola cherry powder and 0.2% rosemary extract) reduced lipid oxidation in both chuck roll and bone-in short rib steaks. Additionally, antioxidants alone or in combination with one another improve objective redness scores by up to 2 points; however, the subjective color panel did not observe lean color improvement.

Extending the Shelf Life of Beef Steaks Using Acerola Cherry Powder and Rosemary Extract

Improvements in retail shelf life of exported beef will help with merchandising and increase competitiveness in the worldwide market for United States beef products. The objective of this study was to determine the effect of topically applying acerola cherry powder or rosemary extract from various suppliers on beef bone-in short rib steak and chuck roll steak shelf life. USDA Choice beef bone-in short ribs (IMPS 123A) and chuck rolls (IMPS 116A) were aged (0°C) for 28 d postfabrication. Following aging, 1.02-cm-thick steaks were cut (N = 126) and systematically assigned to a treatment based on steak location within the subprimal. Treatments included untreated control (C), topically sprayed (2 mL) with an acerola cherry powder solution (0.05%) from 1 of 3 suppliers (C1, C2, C3), or topically sprayed (2 mL) with a rosemary extract solution (0.10%) from 1 of 3 suppliers (R1, R2, R3). Half of the steaks were assigned to day 0 lipid oxidation, metmyoglobin-reducing activity (MRA), and oxygen consumption; the remaining steaks were assigned to color evaluation over 4 d of retail display followed by day 4 lipid oxidation and MRA. Short rib steaks treated with antioxidants had a brighter oxygenated lean color than control steaks (P < 0.001). There was an interaction (P = 0.028) between time of retail display and MRA. Short rib steaks treated with C3 and R2 did not change in MRA between day 0 and 4 (P = 0.620, P = 0.428, respectively). Chuck roll steaks treated with C1, C2, C3, R2, and R3 all had a higher, or more desirable, MRA than the control steaks on day 0 (P < 0.001). Applying topical antioxidants improves the shelf-life stability of steaks from beef bone-in short ribs and chuck rolls aged for an extended period.

26 Extending the Shelf-life of Beef Bone-in Short Rib Steaks Using Acerola Cherry Powder and Rosemary Extract

Abstract Improving the shelf-life of beef bone-in short rib steaks, which are commonly exported, will increase beef export demand and subsequently producer profits. The objective was to determine the effect of the topical application of acerola cherry powder and rosemary extract from various suppliers on beef bone-in short rib shelf-life. Beef bone-in short ribs (IMPS 123A) (n = 18) from USDA Choice carcasses were aged for 28 days post-fabrication at 0°C. Steaks 1.02 cm-thick were systematically assigned based on location to treatments including: untreated control (C), topically sprayed (~2ml) with an acerola cherry powder solution (0.05%) from one of three suppliers (C1, C2, C3), or topically sprayed (~2ml) with a rosemary extract solution (0.10%) from one of three suppliers (R1, R2, R3). Steaks were assigned to day 0 lipid oxidation or 4 days of retail display followed by day 4 lipid oxidation. Steaks were weighed on day 0 and 4 to determine fluid loss. Throughout retail display, objective and subjective color were measured twice daily on the lean and bone marrow portions of the steaks. Data were analyzed using the Mixed Model procedure of the Statistical Analysis System. Lipid oxidation (P = 0.323) did not differ between treatments. However, treatments differed in fluid loss (P = 0.024), where steaks treated with C1, C2, C3, R2, and R3 had less fluid lost than control steaks. Subjective color evaluation of lean color (P < 0.0001) and uniformity (P < 0.001) differed between treatments. Steaks treated with C1, C2, C3, and R3 were a brighter red than control steaks. Treatments differed when measuring bone marrow L* (P < 0.001), a* (P < 0.001), and b* (P = 0.004), where R3 treated marrow was the darkest, reddest, and yellowest. Natural antioxidants, specifically acerola cherry powder and rosemary extract, improved steak color and water holding capacity of beef bone-in short ribs aged for an extended period.

Detection of Beef Adulterated with Pork Using a Low-Cost Electronic Nose Based on Colorimetric Sensors.

The present study was aimed at developing a low-cost but rapid technique for qualitative and quantitative detection of beef adulterated with pork. An electronic nose based on colorimetric sensors was proposed. The fresh beef rib steaks and streaky pork were purchased and used from the local agricultural market in Suzhou, China. The minced beef was mixed with pork ranging at levels from 0%~100% by weight at increments of 20%. Protein, fat, and ash content were measured for validation of the differences between the pure beef and pork used in basic chemical compositions. Fisher linear discriminant analysis (Fisher LDA) and extreme learning machine (ELM) were utilized comparatively for identification of the ground pure beef, beef–pork mixtures, and pure pork. Back propagation-artificial neural network (BP-ANN) models were built for prediction of the adulteration levels. Results revealed that the ELM model built was superior to the Fisher LDA model with higher identification rates of 91.27% and 87.5% in the training and prediction sets respectively. Regarding the adulteration level prediction, the correlation coefficient and the root mean square error were 0.85 and 0.147 respectively in the prediction set of the BP-ANN model built. This suggests, from all the results, that the low-cost electronic nose based on colorimetric sensors coupled with chemometrics has a great potential in rapid detection of beef adulterated with pork.

Effects of increased inclusion of algae meal on finishing steer performance and carcass characteristics.

The deoiled residue from the production of heterotrophic microalgae can be combined with soyhulls to form a novel feedstuff called algae meal (ALG). To determine the effects of replacing corn in a finishing diet with ALG on growth, mineral status, carcass characteristics, and longissimus thoracis fatty acid profile, crossbred steers (168) were blocked by BW (432 ± 30.8 kg) into pens of 6 steers (7 pens per treatment). Pens received 1 of 4 diets: a corn-based control (CON), 14% ALG, 28% ALG (ALG28), and 42% ALG (ALG42). Corn was replaced by ALG on a DM basis. Steer BW were taken on d 0, 1, 28, 56, 74, 101, and 102, and steers were harvested on d 103. Pen was the experimental unit and DMI, ADG, and G:F data were analyzed as repeated measures. Two steers per pen were selected for sampling of blood and liver (d -1 and 96) and collection of rib steaks at harvest. There was a treatment by × time effect ( = 0.10) for overall DMI, where DMI linearly increased ( ≤ 0.008) across all time periods except Day 28 through, 56 when DMI was not different between ALG28 and ALG42. There was a treatment by time effect for ADG ( < 0.01), with ADG linearly decreasing ( ≤ 0.03) in the first and third month, not differing ( = 0.95) in the second month, and linearly increasing ( < 0.01) in the fourth month as ALG increased in the diet. Final BW and HCW did not differ ( ≥ 0.50) between CON- and ALG-fed cattle. There was a treatment × time effect for G:F ( < 0.01), with G:F linearly decreasing ( ≤ 0.01) in the first 3 mo as ALG increased in the diet, whereas G:F linearly increased ( < 0.01) in the fourth month. Based on steer performance, calculated dietary NEg linearly decreased ( < 0.01) as ALG increased in the diet. Yield grade linearly decreased ( = 0.02) and there was a tendency for dressing percent and 12th-rib back fat to linearly decrease ( ≤ 0.10) as ALG increased in the diet. Plasma Cu, Fe, and Mg concentrations were not different ( ≥ 0.31) in CON vs. ALG cattle; however, plasma Zn concentrations linearly increased ( = 0.03) as ALG increased in the diet. Total lipid, SFA, MUFA, and PUFA concentrations in the longissimus thoracis did not differ ( ≥ 0.13) between CON- and ALG-fed cattle. Interestingly, the atherogenic index linearly decreased ( < 0.01) as ALG increased in the diet. Algae meal may have a lesser energy value than corn; however, a minimal effect on carcass performance suggests ALG may serve as a potential replacement for corn in feedlot diets.

Chemical characterisation of pasture‐ and grain‐fed beef related to meat quality and flavour attributes

SummaryThis study examined pasture (PF) and grain feeding (GF) effects on meat quality and nutritional attributes, and correlated sensory attributes with cooked meat volatiles. GF rib steaks had higher fat content (P &lt; 0.05), and were lighter, redder and more yellow (P &lt; 0.05). PF beef contained more (P &lt; 0.05) omega‐3 fatty acids, despite having lower fat content. PF beef had higher antioxidant capacity, and lower oxidation indices (P &lt; 0.05). Diets influenced the volatile profile of cooked meat. Flavour descriptors barny, gamey and grassy were associated with PF, and were uniquely shown here to be positively correlated with aroma volatiles benzaldehyde, toluene, dimethyl sulfone, 3‐heptanone, 2‐ethyl‐1‐hexanol and hexadecanoic acid methyl ester (P &lt; 0.05). GF beef had higher (P &lt; 0.05) levels of hexanal, 1‐octen‐3‐ol, 2,3‐octandione, and 2,6‐bis(1,1‐dimethylethyl)‐4‐ethyl‐phenol, uniquely associated with umami and juicy flavours. The main positive nutritional attribute of PF beef was its low fat content.

Development of a beef flavor lexicon and its application to compare the flavor profile and consumer acceptance of rib steaks from grass- or grain-fed cattle

Ten panelists were selected from the local community to develop a meat lexicon composed of 18 terms that describe flavor attributes found in red meats. This flavor lexicon was used to compare the flavor profile of meat from beef cattle finished on grass or grain. Steaks from grass-fed animals were significantly (P<0.05) higher in barny, bitter, gamey, and grassy flavor, and lower in juicy and umami notes. Gamey, barny, bitter and grassy were some of the attributes inversely correlated to the degree of liking of the meat and therefore can be classified as “negative” attributes. Brothy, umami, roast beef, juicy, browned, fatty and salty are some of the attributes positively correlated to the degree of liking of beef and therefore can be identified as attributes that drive consumers’ acceptance. Steaks from grass-fed cattle were rated by consumers as slightly liked (6.08 on a 9-point scale), while steaks from grain-fed animals were rated as moderately liked (7.05 on a 9-point scale).

Moisture and fat content, marbling level and color of boneless rib cut from Nellore steers varying in maturity and fatness

This study analyzed rib steaks (M. longissimus thoracis) of Nellore steers (n = 60) for intramuscular moisture and fat content, marbling level, and visual and instrumental color. Carcass sides were classified on the kill floor according to teeth maturity (2, 4 and 6 permanent incisors), and fatness (2 — slight and 3 — average). The cranial end of the boneless cut was aged for 14 days, and frozen. Steaks of 2.5 cm thick were cut and thawed for analysis. Moisture and fat content were determined in minced lean. CIE color was measured with a MiniScan XE™, and visually evaluated by an eight-member panel, which also assessed marbling. In this type of cattle and ranges of maturity and fatness considered, increasing either maturity or fatness causes a slight reduction in moisture and an increment in lipid content. But neither maturity nor fatness seems to affect the visual perception of meat color on display.

Effects of teeth maturity and fatness of Nellore ( Bos indicus) steer carcasses on instrumental and sensory tenderness

This study sought to evaluate the effects of teeth maturity and carcass fatness on physical and sensory traits of the beef ribeye ( M. longissimus thoracis). Carcass sides ( n = 60) of Nellore steers were grouped into six categories, according to teeth maturity (2, 4 and 6 permanent incisors), and fatness (2 – slight and 3 – average). The boneless ribeye cuts (6th – 9th ribs) were vacuum packed and aged for 14 days. Steaks, 2.5 cm thick, were evaluated as to sarcomere length, shear force and sensory attributes. Sarcomere length was not affected ( P > 0.05) by maturity or fatness. Teeth maturity did not influence ( P > 0.05) tenderness measured by instrumental or sensory analysis, however rib steaks from fatter carcasses displayed better tenderness ( P < 0.01) and lower cooking losses ( P < 0.01). In the Nellore steer carcasses produced in Brazil, fatness may be more important than teeth maturity to improve meat tenderness.

CORRELATIONS AND PREDICTION EQUATIONS FOR FATTY ACIDS AND SENSORY CHARACTERISTICS OF BEEF LONGISSIMUS RIB STEAKS FROM FORAGE‐FED CATTLE AND RETAIL USDA CHOICE AND SELECT RIB STEAKS

ABSTRACT Rib steaks (n = 52) from forage‐fed cattle and United States Department of Agriculture Choice and Select rib steaks obtained from area supermarkets were utilized to determine correlations between fatty acids and sensory characteristics, to develop prediction models for sensory characteristics, and to determine correlations among fatty acids. The beef/brothy and beef fat sensory characteristics were positively correlated (P &lt; 0.05) with 16:0, 16:1cis‐9 and 18:1, and negatively correlated (P &lt; 0.05) with 15:0, α‐18:3, 20:4, 20:5, 22:5 and 22:6. The grassy sensory characteristic was positively correlated (P &lt; 0.05) with 15:0, 16:1trans‐9, 18:0, 18:2cis‐9,trans‐11 (conjugated linoleic acid [CLA]), α‐18:3, 20:5, 22:5 and 22:6. Regression utilizing stepwise selection to develop prediction equations for sensory characteristics indicated that the beef/brothy sensory characteristic was best predicted (P &lt; 0.05) by the single fatty acid 20:5, with this fatty acid explaining 40% of the variation. CLA and α‐18:3 were utilized in the model that best predicted (P &lt; 0.05) milky/oily flavor, with these two fatty acids explaining 31% of the variation. These results indicate that CLA and the 20‐ and 22‐carbon polyunsaturates have large roles in influencing flavor, causing increases in grassy and milky/oily flavor or decreasing beef/brothy flavor.PRACTICAL APPLICATIONSWith the increase in concentrate feed costs, it has become more important to finish cattle on alternate feedstuffs, particularly forage. However, shifting cattle from concentrate to forage finishing diets may impart different sensory attributes of the beef produced. Therefore, it would be advantageous to be able to predict palatability characteristics such as beef flavor in order to correctly segregate beef into markets that seek and accept different sensory attributes. Results from this study would allow beef to be identified from its fatty acid profile as forage finished or grain finished in sensory characteristics and therefore targeted to the appropriate markets. Furthermore, with these results, it may be possible to produce and correctly classify beef from forage‐finished diets that may exhibit affinities to deposition of fatty acids more closely associated with grain‐finished beef, and therefore fit into those markets.

Thermal denaturation of bovine longissimus thoracis aponeurosis, correlating contraction with optical changes

Beef rib roasts and steaks have a thick connective tissue aponeurosis which is often difficult to gelatinise by cooking. When heated in a water-bath, aponeurosis first increased in reflectance (maximum 0.026 ± 0.021 at 67.1 ± 5.5°C) before decreasing in reflectance as gelatinisation occurred. Contraction reached a maximum of 33.8 ± 15.8% of starting length at 69.2 ± 3.2°C and corresponded to the increase not the decrease in reflectance. Either contraction or increased reflectance might be used to select animals with low-temperature gelatinisation. Key words: Beef toughness, aponeurosis, cooking

Eating Ivy

This essay is both celebration and portrait of the late Barton Rouse and his influential career as chef at the Terrace Club of Princeton University during the writer's undergraduate career. In the late 1980s and early 1990's Barton Rouse transformed a dilapidated building into a culinary mecca. He planned inventive daily menus (chrysanthemum soup; broiled tuna with morel sauce; White Trash Night) and hosted extravagant special events: an anti-Valentine's day dinner, for instance, which featured Blackened Rib Steaks and Catfish Fillets, Black fettuccine with sour cream and lox sauce and red and black caviar, bleeding hearts of beet salad, brandied cherry ambrosia, and mocha espresso cheesecake. The man and his food broke boundaries between high culture and low, good taste and bad, east and west, rural and urban, adult and child. In the process of cooking for his members, Rouse taught hundreds of young people how to eat, but also that cooking was a labor of love and a genuine aesthetic pursuit. His humor, whimsy, and inventive extravagance left a legacy which links inextricably food and politics to our fundamental way of being in the world.

Effects of potassium lactate, sodium chloride, sodium tripolyphosphate, and sodium acetate on colour, colour stability, and oxidative properties of injection-enhanced beef rib steaks

This study determined the effects of potassium lactate (KL), sodium chloride, sodium tripolyphosphate, and sodium acetate on colour, colour stability, and oxidative properties of injection-enhanced beef rib steaks. Enhancement solutions (8.5% pump) contained combinations of KL (0% or 1.5%), sodium chloride (0.3% or 0.6%), sodium tripolyphosphate (0% or 0.3%), and sodium acetate (0% or 0.1%). Steaks were packaged in a high-oxygen modified atmosphere (80% O 2/20% CO 2). Steaks with KL or KL and sodium acetate were darker but more colour stable ( P < 0.05) than control steaks. Steaks had less glossy surfaces when they contained acetate ( P < 0.05) and KL ( P < 0.11). Increasing sodium chloride content resulted in darker, less colour-stable steaks ( P < 0.05). Removing phosphate had little impact on colour ( P > 0.05). Both KL and sodium acetate improved visual appearance of injection-enhanced beef rib steaks, whereas the greater salt level were detrimental.

Fatty acid and sensory characteristics of beef from three biological types of cattle grazing cool-season forages supplemented with soyhulls

Over two consecutive years, the effects of allocating divergent biological types of cattle ( n = 107) to fescue pasture without supplementation, or fescue or orchardgrass pasture with soyhull supplementation on chemical, fatty acid and sensory characteristics were investigated. Cattle from the two supplemented treatments produced beef that had increased ( P < 0.05) percentage lipid and decreased ( P < 0.05) polyunsaturated and n-3 fatty acids compared to the control. However, the n-6 to n-3 ratio was still less than four in beef from the supplemented cattle. Additionally, supplementation did not decrease ( P > 0.05) the CLA present in the longissimus, which can commonly occur when forage-fed cattle are supplemented concentrates. Although supplementation did not impact ( P > 0.05) Warner-Bratzler shear force or tenderness, supplementation of soyhulls reduced ( P < 0.05) the grassy flavor intensity of rib steaks when compared to the control. Biological type did not have a significant influence on most traits analyzed in this study. These results suggest that supplementation of soyhulls to cattle grazing forage can reduce grassy flavor intensity without decreasing CLA proportions, but can reduce the n-3 fatty acid proportions present in the longissimus.

Relationship of texture profile analysis and Warner-Bratzler shear force with sensory characteristics of beef rib steaks

Cyclical texture profile analysis (TPA) parameters measured using a star-shaped probe with two cycles of 80% penetration and Warner-Bratzler shear force (WBS) were compared as predictors of objective tenderness and subjective sensory characteristics of rib steaks from 52 beef loins. The TPA parameters of hardness, cohesiveness and chewiness were negatively correlated ( P<0.05) with trained panel sensory characteristics of initial tenderness ( r=−0.64, −0.41, −0.62, respectively), amount of connective tissue ( r=−0.57, −0.27, −0.55, respectively), overall tenderness ( r=−0.68, −0.39, −0.64, respectively) and overall palatability ( r=−0.56, −0.37, −0.53, respectively). These sensory characteristics were also negatively correlated ( P<0.05) with WBS ( r=−0.61, −0.49, −0.60, −0.56, respectively). Stepwise regression analysis generated prediction equations that included the TPA parameters of hardness and adhesiveness, which accounted for 47, 36, 51 and 38% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Prediction equations using WBS accounted for 37, 24, 36 and 31% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Hence, TPA explained more of the variation in subjective sensory tenderness of the rib steaks than WBS.

Performance and meat quality of beef steers fed corn-based or bread by-product-based diets.

A feeding trial was conducted with beef breed steers (120) to determine the effects of substituting bread by-product (BBy) for whole shelled corn on performance and meat quality. Chemical analysis of each diet ingredient and in vitro rates of digestion from gas production of BBy and corn were determined to provide accurate information for diet evaluations using the 1996 Beef NRC Model Level 2. Bread by-product contained 16% CP (75.6% degradable) and 75.1% non-structural carbohydrates (70% as starch, which had a digestion rate of 16%/h). The steers were given one estrogenic implant (Synovex-S) and started on the experiment at 15 mo of age and an average weight of 364 kg. The cattle were commercially slaughtered in three groups (40 steers at 101, 60 steers at 126, and 20 steers at 160 d on feed) weighing an average of 553 kg when they reached a small degree of marbling. Carcasses were electrically stimulated to prevent cold shortening of muscles. Warner-Bratzler shear force values were measured in rib steaks at 5, 14, and 21 d after slaughter (n = 76). Rib steaks from 30 steers per treatment were evaluated for palatability traits. Use of BBy at 55% of the diet (substituted for 75% of the corn) significantly improved feed efficiency by 8.1%. There were no statistically significant differences between the two diets for effects on ADG, carcass characteristics, shear force values, or sensory panel ratings of tenderness, juiciness, flavor, or overall acceptability. After adjusting intestinal starch digestibility in Level 2 to 63% for the whole corn and 90% for the BBy, predicted ADG matched that observed. Apparent NE(g) values for BBy and corn were 1.57 and 1.41 Mcal/kg, respectively.

Microbiological and Sensory Attributes of Retail Cuts of Beef Treated with Acetic and Lactic Acid Solutions

This research characterized the effect of 0.6 and 1.2% acetic and lactic acids applied for 20 and 120 s at a temperature of 1 to 2°C on total colony forming units (CFU) and Escherichia coli counts, and sensory qualities including shear value, expressible moisture, color and sensory panel of retail cuts of beef rib steaks. Microbial inhibition was directly proportional to the concentration and times of treatment with a 1.2% acid treatment for 120 s being the most effective treatment for reducing microbial counts, for both acids. Although there were significant reductions (p <0.05) in bacterial populations, these reductions which had a maximum of 2.0 log, were of questionable practical significance. The inhibitory effect of the acids decreased with storage time, up to 9 days.Treatment with both the acids resulted in paler meat (p <0.05) than the non-treated control. There were no significant differences (p >0.05) in shear values or expressible moisture due to acid treatment. Sensory panels reported only small differences between the samples.These results indicate that an aqueous acetic or lactic acid treatment of retail beef reduced total CFU and E. coli numbers immediately after treatment, but the magnitude was less than 1 log. However, a residual influence was observed so that after 3 and 9 days both acid treatments inhibited total CPU and E. coli growth by up to 2 logs compared with the non-treated control samples.

Meat composition and palatability of Holstein and beef steers as influenced by forage type and protein source.

This experiment determined meat composition and palatability changes resulting from feeding Holstein (HOL) and crossbred beef (XB) steers diets containing corn silage (CS) or alfalfa haylage (AH) (forage type) and soybean meal (SM) or fish meal (FM) (protein source). Fifty-nine steers (30 HOL and 29 XB) were randomly assigned to diet combinations for a 2 x 2 x 2 (breed x forage x protein) factorial arrangement. Steers were fed to a fat-constant end point (fat depth over the longissimus muscle measured by ultrasound: 1.0 cm XB, .6 cm HOL). Proximate and fatty acid analysis and sensory evaluation were conducted on a rib eye roast and steaks, respectively, removed from the left side of each carcass at ribs 9 to 12. Proximate analysis of the longissimus muscle showed no significant difference (P greater than .05) in moisture, protein, or fat content due to breed, forage, or protein treatment. Forage type had no significant effect (P greater than .05) on amount of individual fatty acids found in longissimus muscle. However, total polyunsaturated fatty acids were higher (P greater than .05) for AH than for CS-fed animals. Longissimus muscle from steers fed FM had higher palmitoleic and lower stearic acid contents (both P less than .05) than longissimus muscle from animals fed SM. Muscle from HOL had higher palmitoleic and lower stearic acid contents than that from XB steers (both P less than .05). There was no significant interaction (P greater than .05) of breed with either diet treatment for individual fatty acid contents.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of days fed, carcass grade traits, and subcutaneous fat removal on postmortem muscle characteristics and beef palatability.

Angus x Hereford steers (n = 48) similar in frame size and in muscle thickness were allotted to eight groups (n = 6) of similar mean live weight for serial slaughter at 28-d intervals (0 to 196 d). Except for d-0 steers, which served as grass-fed controls, all steers were fed a high-concentrate diet during the finishing period. Upon slaughter, one side of each carcass was trimmed of subcutaneous fat in the wholesale rib region. Postmortem longissimus muscle (LM) temperature was monitored for each side during the 24-h chilling period. After quality and yield grade data were collected, rib steaks were removed and aged (7 d) and sensory traits of the steaks were evaluated. Most carcass grade traits increased linearly (P less than .01) with days on feed, whereas most sensory panel variables and marbling increased curvilinearly (P less than .05). Generally, after 56 d on feed, carcasses chilled at slower rates (P less than .05) with increased days fed. Taste panel tenderness, amount of perceived connective tissue, and shear force values peaked at 112 d and were slightly less desirable for cattle fed longer than 112 d (quadratic term, P less than .01). Postmortem muscle temperature at 2.5 h was the chilling time most highly correlated with tenderness values among untrimmed sides. Correlations for shear force with 2.5-h LM temperature, marbling score, days fed, fat thickness, and carcass weight were -.63, -.61, -.56, -.55, and -.53, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of ante-mortem feed and water withdrawal, ante-mortem electrolyte supplementation, and post-mortem electrical stimulation on the palatability and consumer acceptance of bull beef after ageing (6 days at 1°C)

A total of 120 bulls each weighing approximately 500 kg were used to evaluate the effects of withholding feed and water for various intervals pre-slaughter, ante-mortem supplementation with an electrolyte solution, and post-mortem electrical stimulation on the cooking and palatability attributes and consumer acceptance of boneless rib steaks aged for 6 days at 1°C. The results clearly showed the detrimental effects of withholding feed and water pre-slaughter and the beneficial effects of post-mortem electrical stimulation on the eating quality of bull beef aged for 6 days at 1°C. Taste panel ratings of palatability attributes between electrolyte-treated and untreated animals did not differ significantly. However, consumer evaluations indicated a lower overall palatability rating for electrolyte-treated bulls. The results clearly indicate that feed and water deprivation is detrimental to the palatability attributes and consumer acceptance of aged bull beef.