Round Steaks Research Articles

Hot Carcass Fabrication Intervention for Managing Top Round Quality in Heavy Weight Beef Carcasses

Chilling-related meat quality issues have been observed in the deep portion of the top round due to the increase of average beef carcass size. The current study examines the impact of an alternative fabrication method aimed at alleviating top round quality in heavy weight beef carcasses (n = 11; 510 kg average weight). Prior to rigor, the knuckle subprimal was partially fabricated to expose the femur on alternating sides of each carcass (TRT), and each adjacent intact side served as a control (CON). All sides were air chilled (2°C) for 48 h before further fabricating. Temperature loggers placed at approximately 2.54 cm below the top round surface was the superficial (SP) location while loggers for the deep (DP) location were inserted at the midline sagittal center of the round until in contact with the femur bone. Temperature and pH decline were monitored for 48 h. The top rounds were collected, aged under vacuum packaging until 14 d postmortem, and then cut into steaks (2.54 cm). Each steak was separated into SP and DP portions and subjected to Warner-Bratzler shear force (WBSF), consumer sensory panel, and a 3-d retail display analysis which included lipid oxidation and objective color evaluation. The TRT accelerated the rate of temperature decline at the DP location (P < 0.001) and increased the pH decline rate at the SP location (P = 0.029). Retail day and location were more impactful than TRT on objective color traits. SP steaks were more tender (P = 0.001) than DP steaks. Consumer taste panel indicated TRT improved overall acceptability (P = 0.042) and flavor (P = 0.035) of top round steaks regardless of locations. TRT accelerated top round DP chilling rate and elevated steak palatability attributes. Findings of the present study report an improvement of top round steaks due to the innovative fabrication treatment.

Maceration Frequency Impacts Semitendinosus and Biceps femoris Surface Area, Cooking Loss, and Palatability Outcomes

We examined the effect of maceration frequency on surface area, purge loss, and palatability of eye of round and bottom round steaks. Beef eye of round (n = 12) was cut into 8 steaks each and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked slice shear force (SSF) tenderness determinations. Bottom round muscles (n = 12) were cut into 12 steaks and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked SSF or trained sensory evaluations. Steaks were trimmed to a common size (50 cm2 for eye of round and 80 cm2 for bottom round) prior to maceration with a commercial steak tenderizer. Data were analyzed via mixed ANOVA models using a randomized complete block design. Surface area increased (P < 0.001) by 15.4%, 38.6%, and 62.4% for eye of round steaks and 22.0%, 51.3%, and 70.3% for bottom round steaks after 1, 2, or 3 macerations, respectively. Purge losses did not differ (P ≥ 0.247) for either muscle due to maceration frequency. Uncooked SSF values for eye of round steaks were decreased (P < 0.001) by 6.6%, 19.5%, and 40.0% after 1, 2, and 3 macerations; however, cooked SSF values did not differ (P = 0.077). For bottom round steaks, uncooked SSF values were decreased (P < 0.001) by 32.0%, 45.5%, and 67.2% after 1, 2, and 3 macerations; cooked SSF values for steaks macerated 3 times were 26.6% lower (P = 0.022) than steaks macerated 0, 1, or 2 times. Cooking losses were greater (P < 0.001) for macerated eye of round (5.4% to 7.2%) and bottom round steaks (7.6% to 10.8%). Maceration decreased (P < 0.001) sensory juiciness and connective tissue ratings and increased (P < 0.001) sensory tenderness ratings. Maceration increased surface area and improved tenderness.

Influence of Beef Hot Carcass Weight on Sensory Characteristics of Strip Loin, Eye of Round, and Denver Cut Steaks.

The objective of this research was to investigate the influence of beef hot carcass weight (HCW) on consumer sensory attributes. Beef carcasses (n = 116) were selected based on the USDA quality grade and HCW. Lightweight (LW; 296-341 kg), middleweight (MW; 386-432 kg), or heavyweight (HW; 466-524 kg) carcasses with USDA Choice (LC) or USDA Select (SEL) quality grades were used in this study. Carcasses were tracked through fabrication and the semitendinosus, chuck roll, and strip loin were collected and fabricated into eye of round, Denver cut, and strip loin steaks, respectively, for consumer sensory evaluation. USDA Select MW Denver cut steaks had increased overall liking and texture liking scores and were more tender and juicier than the SEL LW steaks (p ≤ 0.02). USDA Select MW strip loin steaks had increased overall and flavor liking scores and were more tender than the SEL LW steaks (p ≤ 0.02). USDA Choice MW eye of round steaks had increased overall, flavor, and texture liking scores and were juicier than the LW eye of round steaks (p ≤ 0.04). The steaks evaluated in this study were differentially impacted by HCW and little to no clear pattern of effects could be determined across cut or quality grade. Additional research is needed to determine the most acceptable HCW from a consumer perspective.

Freezing Temperature and Frequency Influence Purge But Not Tenderness of Beef Semitendinosus

Our objective was to test the effects of freezing temperature and frequency on purge loss and tenderness of eye of round steaks. Commercially sourced USDA Choice beef semitendinosus (n=10) were aged 24 d postmortem. Twelve steaks were cut from each muscle and randomly assigned to 1 of 12 treatments in a 4×3 factorial treatment structure(unfrozen control at 2.2°C or initial freezing at −17.8°C, −26.1°C, or −34.4°C followed by secondary freezing at −17.8°C, −26.1°C, or −34.4°C). Steaks were weighed after cutting and after thawing following each freezing treatment to determine purge losses. Tenderness was assessed via Warner-Bratzler shear force (WBSF); all data were analyzed via mixed models. Lower total purge losses (6.27%) were observed for steaks initially unfrozen (P<0.001), whereas those initially frozen at −34.4°C, −26.1°C, and −17.8°C lost 8.04%, 8.80%, and 8.53%, respectively. No difference (P>0.501) in WBSF was detected among the freezing treatments. These results suggest that freezing temperature and thus freezing rate impact purge loss of eye of round steaks, but mechanical tenderness was not influenced.

Beef Carcass Size and Aging Time Effects on Yield and Color Characteristics of Top Round Steaks

Variation in cut size and weight of fabricated subprimals is a challenge of increased beef carcass weights. Subsequently, variation in carcass size has resulted in consistency challenges during retail display. The objective of this study was to assess three aging periods of commercially available top rounds from varying carcass weights as it relates to yield and color characteristics. In the current study, 21 industry average weight (AW; 340 to 409 kg; no industry discount) beef carcasses and 21 oversized (OS; exceeding 454 kg; receive a discount) beef carcasses were evaluated. Carcasses were selected at a commercial beef packing plant, where the left and right (paired) top round subprimals of each carcass were procured. Paired top rounds were assigned to a short (8 d), average (23 d), or extended (42 d) postmortem aging period. After wet-aging, subprimals were fabricated into steaks for additional analysis. Steaks were evaluated as whole top round steaks or further fabricated into “ superficial ” and “ deep ” portions at 5.08 cm from the superficial edge of the Semimembranosus and the Adductor muscle. Top rounds and steaks from OS carcasses were larger (P < 0.01) than those from AW carcasses. Quantitative color of the anatomically deep locations of the OS steaks had the greatest mean L* (lightness; P < 0.01), a* (redness; P < 0.01) and b* (yellowness; P < 0.01) values. Extending the aging timeline increased L* (lightness; P < 0.01), decreased a* (redness; P < 0.01), and decreased b* (yellowness; P < 0.01). Alternative top round steak fabrication that separates the deep and superficial anatomical locations could be an effective means of providing more uniform steaks.

Nanostructured pH‐Indicator Films Based on Cassava Starch, Laponite, and Jambolan (Syzygium cumini) Fruit Manufactured by Thermo‐Compression

AbstractThis work aims to develop pH‐indicator films based on cassava starch and anthocyanins from jambolan (Syzygium cumini) fruit by thermo‐compression, as well as to study the effect of laponite (Lap) on the physicochemical properties of the thermo‐pressed films. Films manufactured with Lap and jambolan fruit are more colorful than those produced without Lap, indicating that Lap can be used to preserve the purple color in the films during the thermo‐compression or during the exposition to the visible light irradiation. Physicochemical results such as chemical structure, crystallinity, thermal transitions, morphology, thickness, and density suggest that the molecular spacing in the amylose/amylopectin chains is altered with the presence of Lap and jambolan fruit. Finally, films containing Lap and jambolan fruit show visible changes from purple color to yellow color when used to monitor the freshness of round steak stored at −20, 4, and 20 °C. Based on colorimetric and physicochemical results, films based on cassava starch, Lap, and jambolan fruit can be manufactured by thermo‐compression and they can be used to monitor the meat freshness.

Impact of beef carcass size on chilling rate, pH decline, display color, and tenderness of top round subprimals.

Beef carcass weights in the United States have continued to increase over the past 30 yr. As reported by the United States Department of Agriculture, grid-based carcass weight discounts begin when carcasses exceed 408 kg. Despite weight discounts, beef carcass weights continue to increase. At the same time, an increased prevalence of discoloration and color variability in top round subprimals has been observed throughout the industry which may be influenced by the increases in carcass weights. The objectives of this study were to assess the effects of beef carcass size and its relationship to chill time, color, pH, and tenderness of the beef top round. In the current study, eight industry average weight beef carcasses (AW, 341–397 kg) and eight oversized beef carcasses (OW, exceeding 432 kg) were evaluated. Temperatures and pH measurements were observed on both sides of all carcasses for the initial 48 h postharvest at a consistent superficial and deep anatomical location of the respective top rounds. Carcasses were fabricated into subprimals at 48 h and top rounds were aged at 2 °C for an additional 12 d. The superficial location of both AW and OW carcasses cooled at a faster rate (P < 0.01) than the deep locations. The deep location of OW carcasses had a lower pH and a more rapid (P < 0.01) initial pH decline. Quantitative color of steaks from OW carcasses had greater mean L* (lightness; P = 0.01) and initial b* (yellowness; P < 0.01) values. The delayed temperature decline and the accelerated pH decline of the deep location of the top round of OW carcasses occur at different rates than AW carcasses. Delayed rate of cooling leads to irreversible impacts on steak appearance of top round steaks fabricated from OW beef carcasses when compared with AW carcasses.

Relationship between heifer carcass maturity and beef quality characteristics.

Our objective was to determine the relationship between heifer carcass maturity and beef palatability of the longissimus lumborum (LM) and biceps femoris (BF). Left sides of A (n = 30), B (n = 30), and C (n = 30) maturity heifer carcasses under 30 mo of age by dentition were used. Carcasses were selected to ensure similar marbling scores across maturity groups (Small to Modest). Beef strip loins (LM) and outside rounds (BF) were obtained from these carcasses. Steaks were used to measure color stability, lipid oxidation (thiobarbituric acid reactive substances; TBARS), Warner-Bratzler shear force (WBSF), soluble and insoluble collagen, and consumer sensory perceptions. Heifer carcass maturity did not affect pH, fluid loss, WBSF, or collagen content of LM or BF steaks (P > 0.29). In LM and BF steaks, a maturity × day of retail display interaction occurred for TBARS, in which B maturity steaks had lower levels of lipid oxidation compared with A and C maturity steaks from the fourth day to the end of the retail display (P < 0.01). Nevertheless, LM steaks from B maturity carcasses tended to have lower overall acceptability (P = 0.08) and juiciness (P = 0.09) than steaks from C maturity carcasses, but steaks from B and C maturity carcasses did not differ from LM steaks obtained from A maturity carcasses. No differences in tenderness or flavor were observed due to maturity (P > 0.24). Similarly, maturity had no effect on sensory characteristics of BF steaks (P > 0.30). In conclusion, our results indicate that advanced physiological maturity does not decrease palatability of strip loin or outside round steaks from carcasses of heifers under 30 mo of age.

Tenderness and Juiciness of Beef Steaks from Varying Hot Carcass Weights

ObjectivesOur objectives were to determine how hot carcass weights affected temperature decline and pH decline of carcasses, and subsequently shear force, juiciness and color of steaks.Materials and MethodsCarcasses (n = 59) were selected at a commercial abattoir over five collection days at approximately 45 min after exsanguination and sorted by hot carcass weight. Carcasses were separated into light (&lt; 363 kg), medium (363 to 408 kg), or heavy (&gt; 408 kg) weight groups. Temperature decline was monitored with a data logger for 24 h with one probe inserted into the longissimus muscle at approximately the sixth rib and one probe inserted directly into the center of the semimembranosus muscle. Muscle pH was measured in the longissimus and semimembranosus muscle at 0, 4, and 24 h after carcasses were moved into chill coolers. After approximately 24 h of chilling, ribeye area, 12th rib fat, KPH, and USDA Quality and Yield Grades were collected. Ribeye rolls (IMPS 112A) and inside rounds (IMPS 160A) were transported to the North Dakota State University Meat Laboratory and aged in vacuum packaging for 14 d. Ribeye and rounds steaks were fabricated for Warner-Bratzler shear force and color analysis. Color analysis was determined on each steak using a Minolta colorimeter after a 30-min bloom time. A 50-g sample was collected for drip loss analysis. Data were analyzed using the mixed procedure of SAS.ResultsLongissimus muscle temperature at 4 h was less (P = 0.02) in light carcasses compared with heavy weight carcasses and semimembranosus muscle temperature was less (P &lt; 0.0001) in light and medium weight carcasses compared with heavy weight carcasses. There were no differences in pH decline (P ≥ 0.16) among hot carcass weight groups. There were no differences in fat thickness, KPH or marbling score (P ≥ 0.12) among hot carcass weight groups. Longissimus area (P = 0.0002) was larger and USDA final yield grade was greater (P = 0.04) among hot carcass weight groups. There were no differences in drip loss, cook loss or WBSF in either longissimus or semimembranosus muscles (P ≥ 0.10) among carcass groups. Color data indicated that ribeye and round steaks from heavy weight carcasses were redder than steaks from light weight carcasses (P ≤ 0.02).ConclusionHot carcass weight did not have an influence on objective measures of meat palatability traits; however, carcass weight did have an effect on color.

Influence of Cook Method and Degree of Doneness on Beef Flavor Attributes in Round Steaks

ObjectivesIt has been well established that cooking method, marbling level, and cooked internal temperature endpoint affect beef flavor, the most important driver of consumer acceptance. However, beef cuts respond differently to cooking method and cooked internal temperature endpoint based on their inherent chemical characteristics.Materials and MethodsTreatments were: beef cuts (inside round, bottom round, and eye of round); USDA beef quality grade (upper two-thirds Choice and Select); cooking methods (pan grill, stir fry, stew no marinade, stew marinade, and roast); and internal cook temperature endpoints (58, 70, and 80°C). The pan grill cook method included 0.25 and 0.75 in samples from each muscle type. The stir fry cook method treatment was limited to 0.25 in cuts, which were cut into 1.00 in strips prior to cooking. The marinated and non-marinated stew cook method treatments included 0.25 and 0.75 in samples from each muscle. These samples were then cut into 0.25 × 1.00 × 1.00 in and 0.75 × 1.00 × 1.00 in samples prior to cooking. Stew marinated samples were marinated with 118 mL water, 90 mL lemon juice, 30 mL canola oil, 5 mL salt, and 2.5 mL pepper. Two lb roasts were cut from bottom round and eye of round subprimals and inside round subprimals were cut into 2.00 in roasts prior to cooking. An expert descriptive beef flavor and texture attribute panel evaluated each sample using 16-point scales for flavor and texture attributes. Warner-Bratzler shear force (WBSF) were determined. The trained panel results and WBSF values were analyzed using Proc Means and Proc GLMMIX procedures of SAS (version 9.4, SAS Institute, Cary, NC) with a predetermined α of 5%.ResultsQuality grade impacted flavor for the inside round (P &lt; 0.05). USDA quality grade had minimal effect on tenderness as expected, as beef round cuts are highly active muscles in the animal and contain considerable amounts of connective tissue. Cooking method and internal cook temperature endpoint, or cooking time for the stewing cooking treatment, impacted beef flavor to a greater extent (P &lt; 0.05). When pan fried, thicker cuts resulted in more positive flavor attributes. For cuts that were roasted, cooking to higher internal temperatures resulted in higher levels of beef identity, roasted, and umami flavors and less serumy/bloody flavors, as well as decreased tenderness (P &lt; 0.0001), especially in inside round roasts. Marinated round cuts were more tender than their non-marinated counterparts (P &lt; 0.0001). Cuts that were thinner and had longer cooking times were more tender but had more off-flavor attributes (P &lt; 0.05).ConclusionCut thickness, cooking method, length of cooking or internal cook temperature endpoint, and presence of marinade affected flavor and texture of bottom round, eye of round, and inside round cuts. This data will be useful in providing consumer and food service personnel recommendation on how to maximize the flavor and texture of beef round cuts.

Alternative Merchandising Strategy of the Beef Top Round

ObjectivesThe study objectives were to compare the deep (D) vs. superficial (S) portions of the beef top round (NAMI #169A PSO1), semimembranosus (SM) muscle, for tenderness, lipid oxidation, and color.Materials and MethodsTo simulate the retail setting, USDA Choice top rounds (n = 12) were purchased from a commercial food distributer and delivered to the University of Idaho Meat Science Laboratory under refrigeration. Top rounds were aged for 21 to 24 d from their pack date prior to removing the SM for subsequent analysis. Four steaks were cut from each SM proximally to distally. To account for steak location, steaks were systematically assigned to one of the following analyses; Warner-Bratzler Shear Force (WBSF) measurement, lipid oxidation using the Thiobarbituric Acid Reactive Substances (TBARS) method, subjective and objective color analysis on the whole steak to calculate color uniformity (two-toning), and subjective and objective color of a steak separated into D and S portions. The separating cut was made approximately two inches from the superficial edge of the steak. After cutting, WBSF steaks were cooked on clamshell grills to an internal temperature of 71°C. Steaks were then chilled overnight before 6 cores were sheared perpendicular to the muscle fiber direction on a WBSF machine. Steaks were sampled and evaluated for TBARS on Days 0 and 4 of retail display, while color was evaluated subjectively and objectively on Days 0, 1, 2, 3, and 4 of retail display. Steaks used for TBARS and color analysis were placed on white Styrofoam trays, overwrapped with an oxygen permeable PVC film, and displayed in a glass-fronted retail display case at 3°C for 4 d to simulate retail display. Data were analyzed using the mixed models procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC) and significance was determined at P &lt; 0.05.ResultsMean Warner-Bratzler shear force values were lower (P = 0.0012) in the S (4.2 kg) than the D (5.2 kg) portion of the SM. On Day 0, D and S portions had similar TBARS values (0.172 vs. 0.118 mg MDA/kg Meat); yet, by Day 4, the D portion had substantially greater TBARS values than the S portion (0.497 vs. 0.194 mg MDA/kg Meat; treatment × day of retail display interaction, P &lt; 0.0001). The D portion was lighter (higher L*; P &lt; 0.0001) colored than the S portion. Furthermore, the D portion became less red compared to the S portion during simulated retail display (treatment × day of retail display interaction; P &lt; 0.0001). The whole steak had greater levels of two-toning initially, as well as throughout the 4 d of retail display, compared to the D and S portions (treatment × day of retail display interaction; P &lt; 0.0001). Therefore, cutting top round steaks into a D and S portion would result in the steaks being more uniform in color. Additionally, the S portion has longer shelf-life as well as improved tenderness compared to the D portion.ConclusionIn conclusion, the S portion may be able to generate a premium compared to the whole steak at the retail level because of its superiority in color to the D portion and more uniform color compared to the whole steak.

Tenderness and Juiciness of Beef Steaks from Varying Hot Carcass Weights

ObjectivesOur objectives were to determine how hot carcass weights affected temperature decline and pH decline of carcasses, and subsequently shear force, juiciness and color of steaks.Materials and MethodsCarcasses (n = 59) were selected at a commercial abattoir over five collection days at approximately 45 min after exsanguination and sorted by hot carcass weight. Carcasses were separated into light ( 408 kg) weight groups. Temperature decline was monitored with a data logger for 24 h with one probe inserted into the longissimus muscle at approximately the sixth rib and one probe inserted directly into the center of the semimembranosus muscle. Muscle pH was measured in the longissimus and semimembranosus muscle at 0, 4, and 24 h after carcasses were moved into chill coolers. After approximately 24 h of chilling, ribeye area, 12th rib fat, KPH, and USDA Quality and Yield Grades were collected. Ribeye rolls (IMPS 112A) and inside rounds (IMPS 160A) were transported to the North Dakota State University Meat Laboratory and aged in vacuum packaging for 14 d. Ribeye and rounds steaks were fabricated for Warner-Bratzler shear force and color analysis. Color analysis was determined on each steak using a Minolta colorimeter after a 30-min bloom time. A 50-g sample was collected for drip loss analysis. Data were analyzed using the mixed procedure of SAS.ResultsLongissimus muscle temperature at 4 h was less (P = 0.02) in light carcasses compared with heavy weight carcasses and semimembranosus muscle temperature was less (P < 0.0001) in light and medium weight carcasses compared with heavy weight carcasses. There were no differences in pH decline (P ≥ 0.16) among hot carcass weight groups. There were no differences in fat thickness, KPH or marbling score (P ≥ 0.12) among hot carcass weight groups. Longissimus area (P = 0.0002) was larger and USDA final yield grade was greater (P = 0.04) among hot carcass weight groups. There were no differences in drip loss, cook loss or WBSF in either longissimus or semimembranosus muscles (P ≥ 0.10) among carcass groups. Color data indicated that ribeye and round steaks from heavy weight carcasses were redder than steaks from light weight carcasses (P ≤ 0.02).ConclusionHot carcass weight did not have an influence on objective measures of meat palatability traits; however, carcass weight did have an effect on color.

Influence of Cook Method and Degree of Doneness on Beef Flavor Attributes in Round Steaks

ObjectivesIt has been well established that cooking method, marbling level, and cooked internal temperature endpoint affect beef flavor, the most important driver of consumer acceptance. However, beef cuts respond differently to cooking method and cooked internal temperature endpoint based on their inherent chemical characteristics.Materials and MethodsTreatments were: beef cuts (inside round, bottom round, and eye of round); USDA beef quality grade (upper two-thirds Choice and Select); cooking methods (pan grill, stir fry, stew no marinade, stew marinade, and roast); and internal cook temperature endpoints (58, 70, and 80°C). The pan grill cook method included 0.25 and 0.75 in samples from each muscle type. The stir fry cook method treatment was limited to 0.25 in cuts, which were cut into 1.00 in strips prior to cooking. The marinated and non-marinated stew cook method treatments included 0.25 and 0.75 in samples from each muscle. These samples were then cut into 0.25 × 1.00 × 1.00 in and 0.75 × 1.00 × 1.00 in samples prior to cooking. Stew marinated samples were marinated with 118 mL water, 90 mL lemon juice, 30 mL canola oil, 5 mL salt, and 2.5 mL pepper. Two lb roasts were cut from bottom round and eye of round subprimals and inside round subprimals were cut into 2.00 in roasts prior to cooking. An expert descriptive beef flavor and texture attribute panel evaluated each sample using 16-point scales for flavor and texture attributes. Warner-Bratzler shear force (WBSF) were determined. The trained panel results and WBSF values were analyzed using Proc Means and Proc GLMMIX procedures of SAS (version 9.4, SAS Institute, Cary, NC) with a predetermined α of 5%.ResultsQuality grade impacted flavor for the inside round (P < 0.05). USDA quality grade had minimal effect on tenderness as expected, as beef round cuts are highly active muscles in the animal and contain considerable amounts of connective tissue. Cooking method and internal cook temperature endpoint, or cooking time for the stewing cooking treatment, impacted beef flavor to a greater extent (P < 0.05). When pan fried, thicker cuts resulted in more positive flavor attributes. For cuts that were roasted, cooking to higher internal temperatures resulted in higher levels of beef identity, roasted, and umami flavors and less serumy/bloody flavors, as well as decreased tenderness (P < 0.0001), especially in inside round roasts. Marinated round cuts were more tender than their non-marinated counterparts (P < 0.0001). Cuts that were thinner and had longer cooking times were more tender but had more off-flavor attributes (P < 0.05).ConclusionCut thickness, cooking method, length of cooking or internal cook temperature endpoint, and presence of marinade affected flavor and texture of bottom round, eye of round, and inside round cuts. This data will be useful in providing consumer and food service personnel recommendation on how to maximize the flavor and texture of beef round cuts.

Providing Lean Beef for the Next Project: Beef as a Component of a Healthy Dietary Pattern in Cancer Survivors

ObjectivesAn analytical characterization study was conducted at The Ohio State University Department of Animal Sciences in support of a dietary intervention research trial conducted by researchers in the James Comprehensive Cancer Center to incorporate lean beef as a component of a healthy dietary pattern in cancer survivors. For this study, half of the participants were expected to consume 12 to 18 oz of lean beef each week for 24 wk. According to the United States Department of Agriculture (USDA), lean beef is defined in part as beef containing less than 10% lipid by weight. Because lipids constitute the most variable of all nutritional components in meat, quantification of extractable lipid content of beef provided by The Ohio State University Meat Science Laboratory was necessary to ensure the criteria of lean beef was met for the nutritional trial. Therefore, the objective of this study was to quantify extractable lipid content in in all beef samples prior to incorporation into the diet of the study participants.Materials and MethodsBeef semimembranosus, semitendinosus, biceps femoris, and rectus femoris muscles were obtained from the round primal of beef carcasses classified as A maturity. Muscles were trimmed until no more than 8 mm of subcutaneous fat was present. To provide variety for the participants, muscles were fabricated into 9 retail cuts including fine ground beef, coarse ground beef, top round steaks, bottom round steaks, eye of round steaks, thinly sliced beef (cut from the biceps femoris), fajita meat (cut from the semimembranosus), stew meat (cut from the rectus femoris), and cubed steaks (cut from the semimembranosus). Representative samples were collected from each batch of retail cuts and powdered in liquid nitrogen in duplicate. After weighing powdered samples into packets and lyophilizing, extractable lipid content was quantified using a Soxhlet extraction with an 87:13 mixture of chloroform:methanol. Extractable lipid content (%) was determined using the following equation: extractable lipid (%) = (mass after lyophilization- mass after soxhlet extraction) / (original mass of sample) × 100. Any cut that did not classify as USDA lean beef could have been rejected from the study and not provided to the participants. However, no beef was excluded from the study.ResultsA table of descriptive statistics of the extractable lipid content of the 9 different retail cuts is provided (Table 1). A total of 124 samples were analyzed and the beef provided for the study contained an average overall extractable lipid content (%) of 3.6% ± 2.0% (mean ± SD).ConclusionLean beef was provided for this human nutrition study. Further results and conclusions from the dietary intervention research trial are forthcoming.

Relationship between Heifer Carcass Maturity and Beef Palatability

ObjectivesOur objective was to determine the relationship between carcass maturity and beef palatability of strip loin and outside round steaks.Materials and MethodsLeft sides of A (n = 30), B (n = 30), and C (n = 30) maturity heifer carcasses under 30 mo of age by dentition were used. Average skeletal maturities of the groups were A67, B49, and C48. Carcasses were selected to ensure similar marbling scores across maturity groups, and average marbling scores were Sm94, Mt02, and Mt01 for A, B, and C maturity carcasses, respectively. Beef strip loins (IMPS 180) and outside (bottom) rounds (IMPS 171B) obtained from these carcasses were purchased from AB Foods (Toppenish, WA) and transported to the University of Idaho Meat Science Laboratory. Following a 14-d aging period, wholesale cuts were removed from vacuum packaging and ischiatic heads were removed from outside rounds to produce trimmed flats. Two 2.54 cm-thick steaks were cut from the trimmed flats and anterior ends of strip loins. Steaks were used to measure Warner-Bratzler shear force (WBSF), cook loss, insoluble and total collagen, and consumer sensory attributes. Steaks used for WBSF were weighed, cooked on open hearth broilers to an internal temperature of 40°C, then turned and cooked to a final internal temperature of 71°C. Cooked steaks were re-weighed to determine cook loss and cooled to 4°C. Six cores (1.27-cm diameter) were then removed from each steak parallel with the muscle fibers and then sheared perpendicular to muscle fiber orientation using a Warner-Bratzler shear machine (GR Manufacturing, Manhattan, KS). Samples from cooked steaks were frozen at –20°C and used to determine insoluble and total collagen. Sensory panel steaks were frozen at –20°C after aging, and allowed to thaw at 4°C for 24 h prior to the consumer panel. Steaks were cooked as previously described and four 1.27-cm × 1.27-cm × steak thickness cubes were obtained from each steak. Separate sensory panels were conducted for strip loin and outside round steaks. Consumers (n = 72 panelists per panel) evaluated cooked samples for overall acceptability, tenderness, juiciness, and flavor using a 9-point scale (9 = like extremely, 1 = dislike extremely). Using an incomplete block design, panelists evaluated 5 samples from the 3 maturity groups. Data were analyzed using the Mixed Model procedure of the Statistical Analysis System (SAS Inst. Inc., Cary, NC). Significance was determined at P < 0.05 and data were considered trending at P < 0.10.ResultsHeifer carcass maturity did not significantly affect WBSF or cook loss for either outside round or strip loin steaks (P > 0.23). Likewise, insoluble and total collagen were not different for either steak type from A, B, or C maturity carcasses (P > 0.89). Strip loin steaks from C maturity carcasses tended to have higher overall acceptability (P = 0.08) and juiciness (P = 0.09) than steaks from B maturity carcasses, but steaks from B and C maturity carcasses did not differ from strip loin steaks obtained from A maturity carcasses (P > 0.11.). No differences in tenderness or flavor were observed due to maturity (P > 0.24). Similarly, maturity had no effect on sensory characteristics of outside round steaks (P > 0.30).ConclusionIn conclusion, advanced skeletal maturity does not decrease palatability of carcasses from cattle under 30 mo of age.

National Beef Tenderness Survey—2015: Palatability and Shear Force Assessments of Retail and Foodservice Beef

Beef retail steaks from establishments across 11 US cities and beef foodservice steaks from establishments in 6 US cities were evaluated using Warner-Bratzler shear (WBS) force and consumer sensory panels. The average post-fabrication aging time of steaks at retail establishments was 25.9 d with a range of 6 to 102 d, and those from foodservice establishments averaged 31.5 d with a range of 3 to 91 d. The retail steaks with the lowest WBS value (P &lt; 0.05) was the boneless top loin, compared to the top round steaks, which had the higher (P &lt; 0.05) average WBS value. For the foodservice sector, top loin and ribeye steaks had the lowest (P &lt; 0.05) WBS values, whereas the top sirloin represented the highest (P &lt; 0.05) WBS values. The top blade retail steaks received among the highest consumer ratings (P &lt; 0.05), whereas the top round and bottom round steaks received among the lowest (P &lt; 0.05) consumer ratings for overall liking, tenderness liking, tenderness level, flavor liking, and juiciness liking. For the foodservice sector, the ribeye and top loin steaks were rated higher (P &lt; 0.05) than top sirloin steaks for all consumer rating categories. The WBS values and sensory ratings were comparable to previous surveys, indicating no substantial changes in tenderness. Additional emphasis in improving the tenderness of top and bottom round steaks is necessary to increase consumer acceptability of these cuts.

Relationship between Physiological Maturity and Retail Shelf Life in Heifer Carcasses

ObjectivesOur objective was to determine the relationship between carcass maturity and retail fluid loss, color stability, and lipid oxidation of strip loin and bottom (outside) round steaks.Materials and MethodsRight sides of A (n = 24), B (n = 23), and C (n = 24) maturity heifer carcasses were used. Carcasses under 30 mo of age based on dentition, and with a “small” (Sm) to “moderate” degree of marbling were selected. Beef strip loins (IMPS 180) and outside rounds (IMPS 171B) obtained from these carcasses were purchased from AB Foods (Toppenish, WA) and transported to the University of Idaho Meat Science Laboratory. Following a 14-d aging period, wholesale cuts were removed from vacuum packaging and ischiatic heads were removed from outside rounds to produce trimmed flats. Two 2.54 cm-thick steaks were cut from the trimmed flats and anterior ends of strip loins. One steak was used to measure retail fluid loss and color stability and the other was used to measure lipid oxidation. Steaks were placed in white Styrofoam trays with the freshly cut surface exposed and overwrapped with an oxygen permeable PVC film. Steaks used to determine retail color stability were weighed prior to packaging and displayed in a glass-fronted retail display case at 2.6°C for 6 d. Steaks were allowed to bloom for at least 60 min and then two objective color measurements per steak were taken using a Hunter MiniScan EZ. This represented d 0 of retail display, and subsequent color measurements were taken on d 1, 2, 3, 4, 5, and 6. The instrument was set to illuminant A and Commission International de l’Eclairage (CIE) L*, a*, and b* values were recorded. Three evaluators measured oxygenated lean color, surface discoloration, % discoloration, amount of browning, and color uniformity on each day of retail display. Following 6 d of retail display, steaks were removed from packaging and reweighed to determine retail fluid loss. Thiobarbituric acid reactive substances (TBARS) were quantified in samples obtained from steaks on d 0, 2, 4, and 6 of retail display. Data were analyzed using the Mixed Model procedure of the Statistical Analysis System (SAS Inst. Inc., Cary, NC) and significance was determined at P < 0.05.ResultsMarbling scores of the carcasses were not different across maturity groups (P = 0.79). Average marbling scores were Sm93, Sm99, and Sm98 for A, B, and C maturities, respectively. Heifer carcass maturity did not affect retail fluid loss in either strip loin or bottom round steaks, or color stability of strip loin steaks (P > 0.20). However, the amount of browning in B maturity bottom round steaks was less (P < 0.05) than C maturity steaks. Furthermore, a maturity by day of retail display interaction was observed for bottom round oxygenated lean color (P < 0.001). Lean color of A, B, and C maturity steaks was similar until d 3 of retail display, after which C maturity steaks darkened at a faster rate than A or B maturity steaks. For bottom round steaks, a maturity by day of retail display interaction was observed for TBARS values. Interestingly, lipid oxidation in A versus B and C maturity steaks occurred faster from d 4 to 6 of retail display.ConclusionIn conclusion, advanced skeletal maturity in heifer carcasses under 30 mo of age has little or no negative effect on retail product characteristics.

Composition of free and peptide-bound amino acids in beef chuck, loin, and round cuts1,2

Meat is a food for humans. However, beef consumption in the United States has steadily declined by >14% over the past decade due to a variety of factors, including insufficient knowledge of animal protein. This study quantified all proteinogenic AA as well as nutritionally and physiologically significant nonproteinogenic AA and small peptides in beef cuts from 3 subprimals (chuck, round, and loin). Beef carcasses ( = 10) were selected at 3 commercial packing plants in the United States. Retail-cut samples were analyzed for the nitrogenous substances after acid, alkaline, or enzymatic hydrolysis and after deproteinization. In these chuck, round, and loin cuts, total amounts of glutamate (free plus peptide bound) were the highest (69-75 mg/g dry weight) followed by lysine, leucine, arginine, and glutamine in descending order. This is the first study to determine aspartate, asparagine, glutamate, and glutamine in meat proteins of any animal species. In all the beef samples evaluated, glutamine was the most abundant free AA (4.0-5.7 mg/g dry weight) followed by taurine, alanine, glutamate, and β-alanine. Additionally, samples from all beef cuts had high concentrations of anserine, carnosine, and glutathione, which were 2.8 to 3.7, 15.2 to 24.2, and 0.68 to 0.79 mg/g dry weight, respectively. Beef top loin steaks appear to provide higher protein nutrition values than top round steaks and under blade roasts, but all are excellent sources of proteinogenic AA as well as antioxidant AA and peptides to improve human growth, development, and health. Our findings may help guide future decisions regarding human and animal nutrition.

Freezing Strip Loin and Top Round Steaks Improves Warner-Bratzler Shear Force

Postmortem aging of steaks is a common practice used to improve tenderness of beef steaks. The impact of proteolysis and improvement in tenderness due to aging varies among muscles. When designing research protocols, samples for Warner-Bratzler shear force (WBSF) are often frozen for later analysis because of convenience and time limitations. Freezing stops postmortem aging and allows for storage until meat can be cooked for WBSF and/or sensory analysis. However freezing meat may cause damage to cell membranes resulting in lower Warner-Bratzler shear force (improved mechanical tenderness), lower water holding capacity, and greater moisture loss during cooking. Several researchers have indicated that freezing strip loin (Longissimus muscle) steaks may lower Warner-Bratzler shear force (improve tenderness) compared with those not previously frozen and sheared fresh. However, these results have been inconclusive for steaks from other muscles. Therefore, the objective of this study was to determine the effects of postmortem aging time and freezing on Warner-Bratzler shear force of six muscles from the beef hindquarter.

가열 한우육 및 호주산우육 스테이크에서 심부온도에 따른 glucose, lactate 및 핵산 분해 물질 함량 비교

본 연구는 가열 한우육 및 호주산우육 스테이크에서 심부온도에 따른 glucose, lactate 및 핵산 분해 물질 함량을 비교하고자 실시하였다. 시료로 한우육(거세우, 1등급) 및 호주산우육(Bos indicus, 100일 곡류 비육)의 등심(M. longissimus dorsi)과 우둔(M. semimembranosus)를 약 2 cm 두께로 절단하여 각각 세 그룹으로 나누고, <TEX>$180^{\circ}C$</TEX> 오븐에서 심부온도가 각각 50, 70 및 <TEX>$90^{\circ}C$</TEX>가 되도록 가열하였다. Glucose 함량은 심부온도에 관계없이 한우육 스테이크가 호주산우육 스테이크에 비해 현저하게 높았다(P<0.05). 이와 반대로 lactate 함량은 한우육 스테이크가 호주산우육 스테이크보다 낮았다(P<0.05). 핵산 분해 물질 중 Hx 함량은 모든 심부온도에서 한우육 스테이크가 호주산우육 스테이크보다 낮았던 반면(P<0.05), GMP, IMP 및 inosine 함량은 한우육 스테이크가 높았다(P<0.05). 심부온도가 증가함에 따라 쇠고기 스테이크의 glucose 함량은 감소하는 경향을 보였으나, lactate 함량은 일정한 경향을 보이지 않았다. 또한 핵산 분해 물질 함량은 심부온도의 증가에 따라 유의적인 변화를 보이지 않았다. 따라서 가열 한우육 스테이크의 단맛 및 감칠맛 관련 풍미 전구물질 함량이 호주산우육 스테이크보다 높았다. This study was conducted to compare the glucose, lactate, and nucleotide degradation products content of cooked beef steaks from Korean Hanwoo (quality grade: 1) and Australian cattle (Bos indicus, grain-fed for 100 d) by internal temperature. The loins (M. longissimus dorsi) and top rounds (M. semimembranosus) from two cattle breeds were cut into about 2 cm thickness and then cooked in a <TEX>$180^{\circ}C$</TEX> electronic oven until internal temperature attained to 50, 70, or <TEX>$90^{\circ}C$</TEX>. Regardless of internal temperature, glucose content was higher (P<0.05) in cooked loin and top round steaks from Hanwoo compared to those from Australian cattle. Lactate content was shown to be lower (P<0.05) in cooked steaks from Hanwoo than in those from Australian cattle. Lower (P<0.05) hypoxanthine and higher (P<0.05) guanosine 5'-monophosphate, inosine 5'-monophosphate, inosine contents were observed in cooked steaks from Hanwoo. Furthermore, glucose content tended to be decreased by internal temperature but nucleotide degradation products content was not changed by internal temperature. Therefore, these findings suggest that cooked Hanwoo beef steaks had higher flavor precursors related to sweet and umami tastes than cooked Australian beef steaks