Steak Thickness Research Articles

A South African beef quality survey

In this study a survey of various meat quality characteristics of beef loin cuts was conducted in the City of Tshwane Metropolitan Municipality (Gauteng Province of South Africa) to determine the variation and consistency of beef quality of products purchased over time. Four hundred and twenty beef loin samples were collected on 20 occasions over 308 days from 13 outlets of 2 supplier types (butcher and supermarket). Packaging type, label information and price were considered for the evaluation of meat tenderness, colour, cooking loss, tissue composition and steak thickness. The results demonstrate that large variation in characteristics relevant to consumers' choice and satisfaction among and within different products sold as porterhouse steak in South Africa. In particular, muscle tenderness varied (P < 0.0001) across the 20 products and also showed significant inconsistency over the 20 purchasing events for certain products.

Cooking Surface Temperatures, Steak Thickness, and Quality Grade Effects on Volatile Aroma Compounds

Volatile aroma compounds were evaluated in USDA Top Choice and Select beef top loin steaks cut 1.3 cm (THIN) or 3.8 cm (THICK) and cooked on a commercial flat top grill at 177°C (LOW) or 232°C (HIGH) grill surface temperature. Gas chromatography/mass spectrophotometry was used to evaluate volatile aroma compounds. USDA Select steaks had more 2-octene and less trimethyl pyrazine in (P &amp;lt; 0.05) THIN steaks than THICK steaks, whereas Choice was unaffected by steak thickness (P &amp;gt; 0.05). Benzene acetaldehyde was higher and 4-hydroxybenzoic acid was higher in Select LOW grill temperatures compared with Select HIGH grill temperatures, whereas 5-methyl-2-furan carboxaldehyde was only present in Choice HIGH grill temperatures (P &amp;lt; 0.05). Two acids, 3 alcohols, 1 aldehyde, 1 alkane, and 1 ketone volatile aroma compound were higher (P &amp;lt; 0.05) for LOW compared with HIGH. Conversely, 5 alcohols, 2 aldehydes, 2 alkanes, all 4 furans, 6 ketones, 4 pyrazines, along with 1H-indole, 2 pyrroles, 2 pyridines, and 1 benzene aroma compound were higher (P &amp;lt; 0.05) in HIGH compared with LOW. Additionally, 1 alcohol, 2 aldehydes, 1 ketone, 1 sulfur-containing, and 6 other volatile compounds were lower, whereas 1 acid, 1 alcohol, 1 aldehyde, 2 furans, 1 ketone, 3 pyrazines, 1 sulfur-containing, and 1 other volatile compound were higher in the THIN compared with THICK. Some aroma compounds such as 2-butanone, 4-methyl-2-pentanone, 1-ethyl-1H-pyrrole, 1-methyl-1H-pyrrole, and 2-methyl-pyridine were only present in THICK cooked HIGH (P &amp;lt; 0.05). Steak thickness and grill temperature are important factors to consider in the development of positive Maillard reaction products. Key findings are that high grill temperatures and/or thick steaks with longer grilling times are required for the development of key Maillard reaction products and many Maillard reaction products were only found in the most severe high-temperature, long-time grilling scenarios.

Development and validation of a computational model for steak double-sided pan cooking

The objective of this study was to develop and validate a numerical model to adequately simulate the double-sided pan cooking of beef in a domestic environment. The proposed model takes into account the heat flow from the pan to the meat and the moisture transfer, simultaneously with the meat deformation. The model considers the swelling pressure gradient caused by the shrinkage of the meat fibers and connective tissue due to the denaturation of proteins and the loss of the water holding capacity during cooking. The model results were successfully verified with experimental data of the central temperature and weight loss recorded during cooking for three degrees of doneness. The measured experimental temperatures at the center of the meat were 30 ± 3 °C (very rare), 44 ± 3 °C (rare) and 57 ± 2 °C (done) for a 19 mm steak thickness. Meanwhile, their water losses were 4 ± 2 % , 8 ± 1 % and 11 ± 2 % , respectively. The root mean squared errors of the model predictions were 2.16 °C (very rare), 3.56 °C (rare) and 4.57 °C (done) for the central temperature and 1.48 % , 2.08 % and 2.40 % , respectively for the water loss. The model also correctly predicts cooking times for steaks of different thicknesses, taking weight loss as a reference to set this time. The proposed model is postulated as a useful cooking assistance tool to estimate the optimal cooking time according to consumer preferences.

Thermophysical Properties of Beef Steaks of Varying Thicknesses Cooked With Low and High Grill Surface Temperatures

The objective of this study was to determine the thermodynamic and physical properties of beef strip loin steaks of varying thicknesses and USDA quality grades cooked with high and low grill surface temperatures. Thermal characteristics described by changes in the denaturation temperature (between 55°C – 60°C) and enthalpies of protein denaturation (70°C – 75°C) both differed (P = 0.031 and P = 0.001, respectively) among thick steaks, with thick steaks cooked on a high grill surface temperature having a lower denaturation temperature and enthalpy compared with thick steaks cooked on a low grill surface temperature. No differences (P &amp;gt; 0.05) were observed among thin steaks for denaturation temperature or enthalpy. The elastic behaviors of the surface and center of the steaks were analyzed to determine how the microstructure of the beef responded to applied stress. The elastic behavior of steak centers was influenced in a three-way interaction (P = 0.029) between quality grade, steak thickness, and grill surface temperature. The elastic behavior of the surface of steaks was influenced by the interaction of quality grade and steak thickness (P = 0.031). These interactions, along with the differences in the thermal characteristic of proteins, suggest that the microstructure of steaks was affected by each cooking treatment group. Hardness, resilience, and chewiness were each influenced by a three-way interaction (P = 0.023; 0.014; and 0.030; respectively). Thin steaks possessed greater cohesiveness (P = 0.038) and shear force ( P = 0.007) values. Meanwhile, thin steaks exhibited lower springiness (P = 0.002). The measured alterations in thermal and physical proper- ties in the beef steaks suggest that the composition, thickness, and cooking regiments impact the microstructure of beef, and this was ultimately confirmed through textural measurements. The results of this research can be used in the design of cooking processes that match beef characteristics.

High-intensity ultrasound applied on cured pork: Sensory and physicochemical characteristics.

This research aimed to evaluate the physicochemical characteristics and their relationship with sensory properties of cured porcine m. longissimus lumborum assisted by high‐intensity ultrasound (HIU, 37 kHz, 22 Wcm−2). An experiment was designed with three factors at two levels each: type of curing (immersion or ultrasound‐assisted ‐UA‐), immersion time (30 or 90 min), and steak thickness (1.27 or 2.54 cm). After treatment and 7 days of storage at 4°C, the percentage of salt, pH, CIE L* a* b* color, water holding capacity (WHC), and shear force were determined in the samples. A quantitative descriptive analysis was performed using eight trained panelists. The HIU significantly increased the percentage of NaCl (p < .0005) and decreased the color saturation of the meat (p < .05), but did not affect the luminosity, redness (a*), yellowness (b*), pH, WHC, or shear force (all p > .05). The thickness of the steak had significant effects on almost all of the evaluated variables. Samples with 1.27 cm thickness had lower shear force, higher WHC and salt percentage (p < .0001). In agreement with this, the sensory profiles showed that the 1.27 cm samples treated with HIU for 30 min were perceived as less tough (more tender) and juicier.

Effects of Dry Heat Cookery Method and Quality Grade on the Palatability of Beef Strip Loin Steaks

ObjectivesCooking meat using a clamshell grill has become common in university research settings due to speed, relative low cost, and acceptable repeatability. However, other cooking methods such as charbroiling and salamander grills have also become a popular method in the hotel and restaurant industry. The objective of this experiment was to evaluate the effect of different dry heat cooking methods on beef palatability across a range of USDA quality grades.Materials and MethodsA consumer panel (n = 288) was conducted at Texas Tech University. Strip loin steaks from four different USDA quality grades (Prime, upper 2/3 Choice, lower 1/3 Choice, and Select) were cooked using one of four cooking methods: electric clamshell grill (CLAM), flat top gas grill (FLAT), Charbroiler gas grill (CHAR), or Salamander gas broiler (SAL). After cooking to medium degree of doneness (70–72°C), steaks were cut into cubes (1.3-cm × 1.3-cm × steak thickness), and two cubes were served immediately to 6 predetermined consumers from each steak. Each consumer evaluated 8 samples, representing half of the 16 possible quality grades × cooking method treatment combinations. Consumers scored juiciness, tenderness, flavor liking, and overall liking using electronic ballots with the zero-point anchors labeled as extremely dry, extremely tough, dislike flavor extremely, and dislike overall extremely and the 100-point anchors labeled as extremely juicy, extremely tender, like flavor extremely, and like overall extremely. Also, consumers rated each sample as either acceptable or unacceptable for each palatability trait.ResultsThere were no interactions between the cooking method and quality grade for any of the palatability traits (P &gt; 0.05). Steaks cooked on CHAR had greater (P &lt; 0.05) flavor and overall liking scores, as well as a greater percentage of samples (P &lt; 0.05) that were considered acceptable overall compared to the other cooking methods. Steaks cooked on FLAT were scored lower (P &lt; 0.05) for tenderness and juiciness compared with all other cooking methods. Steaks cooked on CLAM, SAL, and CHAR were scored similarly for tenderness and juiciness (P &gt; 0.05). Steaks cooked on FLAT were scored lower (P &gt; 0.05) than CHAR and SAL for overall liking. Steaks cooked on CLAM had lower (P &lt; 0.05) flavor liking scores than CHAR and SAL. Prime samples had greater scores (P &lt; 0.05) than Low Choice and Select, which were similar (P &gt; 0.05), for tenderness, juiciness, flavor liking, and overall liking, but Prime did not differ from Top Choice (P &gt; 0.05) for any palatability traits.ConclusionThese results indicate cooking method had a significant impact on consumer palatability ratings, and those results were consistent across a range of quality grades. Even though these cooking methods are all classified as dry heat cookery methods, consumers in this study were able to detect differences in tenderness, juiciness, flavor liking, and overall liking. This may be due to increased cooking times or differing types of heat transfer possessed by the various cooking methods. These data suggest cooking steaks by CHAR resulted in the most desirable eating experience, and cooking steaks on FLAT and CLAM were less desirable. However, the low eating satisfaction of FLAT can be linked to low tenderness and juiciness, whereas CLAM liked less due to low flavor liking.

Sorting Beef Subprimals by Ribeye Size at the Packer Level to Maximize Utility and Product Uniformity in Foodservice and Retail Sectors

ObjectivesTo determine the impact of sorting beef carcasses at the packer level by ribeye area, instead of sorting subprimals by weight, to provide more consistent products for the end user via foodservice and retail channelsMaterials and MethodsInstrument grading technology was used to select 100 USDA Choice, yield grade 2 or 3 sides, and 100 USDA Select, yield grade 2 or 3 sides. Carcass sides were sorted into one of five ribeye area (REA) categories, as outlined in Tabsle 6.USDA Choice carcass sides were fabricated to remove beef rib, ribeye, lip-on (IMPS 112A) and beef loin, strip loin, boneless (IMPS 180) from each USDA Choice. Beef loin, tenderloin, full, side muscle on, partially defatted (IMPS 189B) subprimals were procured from each USDA Select side. Subprimals were weighed, trimmed to specification, and passed through a 3-D visual analysis portioning machine and to obtain scan data for a variety of portioning outcomes generated by simulation software.ResultsBased on input from our foodservice collaborators, 1.25 inches (3.18 cm) was identified, for ribeye and strip loin steaks, as the targeted optimal thickness to meet consumer expectations. After evaluation of multiple portioning outcomes, it was determined that a 14.00-ounce (396.89 g) portion, for each REA category, most consistently delivered the preferred steak thickness identified previously. REA categories 1 and 2 most frequently produced desirable thickness and portion weight outcomes in ribeye and strip loin steaks. Statistical analysis of number of portions per subprimal stratified by portion weight and portion thickness revealed differences (P &lt; 0.05) across all REA area categories in both ribeyes and strip loins. As portion weight and thickness increased, steak portion number tended to decrease. In tenderloins, an optimal steak thickness of 1.75 to 2.00 in (4.45 to 5.08 cm) was identified as optimal. Most frequently, 8, 9, and 10-ounce (226.80, 255.15, and 283.50 g) portions met the targets for optimal portion weight and thickness parameters. For tenderloins, number of portions by portion weight showed significant differences (P &lt; 0.05) in all ribeye area categories with the exception of 7-ounces (198.45 g) and showed no differences when stratified by portion thickness. In this investigation, USDA Choice carcasses (r = 0.76) and USDA Select carcasses (r = 0.56) expressed moderate correlation between REA area and hot carcass weight.ConclusionResults of the present study suggest strip loin, ribeye, and tenderloin subprimals from carcasses possessing a ribeye area ranging from 74.8 cm2 to 87.1 cm2 offered the greatest level of utility when portioned for use in foodservice and retail sectors. Further research is warranted to continue examining the merit of sorting carcasses by ribeye area at the packer level, but results of this study suggest that there is potential for improved consistency and utility of subprimals in the foodservice and retail sectors.Table 6.Ribeye area (REA) categories and associated acceptable REA ranges.

Metabolomic Predictors for Flavor Potential of Beef Steaks Differing in Quality Grade, Aging Time, and Degree of Donenesss

ObjectivesThe objective of this project was to explore metabolomic predictors that could determine the potential of beef strip loin steaks differing in quality grade, aging time, and degree of doneness to develop positive flavors.Materials and MethodsUSDA Select (n = 18) and USDA Upper 2/3 Choice (n = 18) beef strip loins (IMPS 180) were collected from a processing plant. Loins were halved, and each half was wet aged for either 10 or 20 d in a cooler kept at 2°C. After aging, loins were cut into 2.54 cm steaks, individually vacuum packaged and stored in a freezer at –40°C. Prior to cooking steaks were thawed in a 4°C cooler for 12 to 24 h. Steaks were cooked on a flat top griddle set to 204.4°C (± 11.1°C) to one of three degrees of doneness: 63°C (medium rare), 71°C (medium) or 80°C (medium well). A six-member expert trained descriptive attribute panel was trained on 16 major attributes, 4 other attributes, and 3 texture attributes from the beef lexicon for 6 d prior to testing. Panelists were trained to scale each attribute on a sixteen-point intensity scale (0 = none, 15 = extremely intense). Panelists were served two random, representative cubes (1.3 cm × 1.3 cm × steak thickness) from each steak in a plastic souffle cup labeled with a random three-digit code. Panelists were seated in a breadbox-style booth under red lighting to eliminate degree of doneness bias. Portions from one raw steak from Quality Grade (QG) × aging combination from each loin was used for high performance liquid chromatography (HPLC) analysis. Samples were homogenized and extracted with a water/acetonitrile solution before being filtered. The lipid fraction was removed via solid phase extraction. Samples were then centrifuged and injected into the HPLC. Data was analyzed as a factorial arrangement of a completely randomized design.ResultsUSDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors and were juicier and more tender compared to USDA Select steaks, which were more intense in metallic and bitter flavors (P &lt; 0.05). Steaks aged for 20 d were juicer and more tender than 10-d aged steaks (P &lt; 0.05). However, 20-d aged steaks also had more intense sour, liver-like, and musty earthy/humus flavors and a less intense brown flavor compared to 10 d aged steaks (P &lt; 0.05). Steaks cooked to 80°C had more intense beef identity, brown, roasted, and umami flavors than steaks cooked to a lower degree of doneness (P &lt; 0.05). Steaks cooked to either 63°C or 71°C had more intense bloody, metallic, and sour flavors and are juicier and more tender than steaks cooked to the higher degree of doneness (P &lt; 0.05). The HPLC analysis of raw steak samples indicated a total of 54 compounds appeared in at least 80% of one treatment. Additionally, there were 2 peptides and 1 sugar that were significantly (P &lt; 0.05) upregulated in the Choice, 20-d-aged strip loins. Additionally, 14 compounds were identified that were shared across all four QG × aging combinations. This included 11 peptides, 2 phospholipids, and 1 heterocyclic aromatic hydrocarbon.ConclusionThese compounds could be indications of the potential for steaks to form positive flavor attributes found in USDA Choice steaks and 20-d aged steaks as described by trained panel analysis.

Time and Temperature Kinetics for the Development of Volatile and Non-Volatile Flavor Compounds in Steaks

ObjectivesThe objective of this study was to utilize mass spectrometry (MS) instrumentation to define flavor differences in beef strip loin steaks cooked on five different surface temperatures.Materials and MethodsUSDA Select strip loins (n = 30) were selected from carcasses at a commercial major packing plant in Texas. After aging 14d, the loins were cut into 2.54 cm thick steaks, randomly assigned a grill surface temperature of 149, 177, 204, 232, or 260°C, individually vacuum-packaged and frozen at –10°C until analysis. Steaks were cooked on an electric flat top grill pre-heated to the corresponding temperature treatment. Steaks were turned at an internal temperature of 35°C and removed at 71°C (medium degree of doneness). Cubes (1.3cm × 1.3cm × steak thickness) representative of those served to a trained sensory panel were frozen and held at –80°C until further analysis. For GC/MS analysis, the samples were weighed and placed in a 473 mL glass jar with a Teflon lid held in a water bath at 60°C for 2h. The collection of volatiles from the headspace was done with a solid phase micro-extraction (SPME) sampler and a multi-dimensional GC/MS. For HPLC/MS-QTOF analysis, frozen samples were homogenized in a blender and 2 g were mixed with 8 mL acidified acetonitrile (0.1% formic acid). The supernatant was exposed to dSPE Enhanced Matrix Removal and dried with 3.5 g MgSO4. Samples were analyzed at a 1:5 dilution using reverse-phase chromatography on an Agilent 6545 LC/MS-QTOF with a gradient mobile phase in both positive and negative ion modes. Data were analyzed as linear and/or quadratic effects (P &lt; 0.05) with grill surface temperature as the independent variable. Least squares means, discriminant analyses, and partial least squares regression analyses for compounds were calculated.ResultsBoth octane (gasoline aroma) and undecane (allspice aroma) increased (P &lt; 0.02) linearly with grill temperature. With the exception of pentanal (fermented wine aroma), which decreased (P = 0.027) as grill temperature increased, all other aldehyde compounds increased (P &lt; 0.05) linearly as the grill temperature increased. Pyrazines (roasted, coffee, and nutty aromas) and ketones (fruity, fatty aromas) generally increased (P &lt; 0.03) as grill temperature increased. 2,3,5-trimethyl-6-ethyl pyrazine, 2,3-diethyl-5-methyl pyrazine, 2,5-dimethyl pyrazine and 3,5,-diethyl-2-methyl-pyrazine were only present when the grill temperature reached 260°C. Nonvolatile compounds (n = 247 positive ion and 140 negative ions) were identified. Significant (P &lt; 0.05) patterns of increasing intensity with increased grill temperature were observed in sugar-amino derivatives such as betaine, 2-dimethylamino-5,6-dimethylpyrimidin-4-ol, and (S)-N-(4,5-dihydro-1-methyl-4-oxo-1H-imidazol-2-yl) alanine. A point of inflection was observed at a grill temperature of 232°C across a majority of increasing compounds, suggesting a critical temperature for the regulation of flavorful products from the Maillard reaction.ConclusionVolatile and nonvolatile compounds known to contribute to positive flavor attributes associated with the Maillard reaction are considerably influenced by grill surface temperature. It appears that a grill temperature from 204 to 232°C is optimal for generation of volatile and nonvolatile flavor compounds.

Steak Thickness, Cook Surface Temperature and Quality Grade Affected Top Loin Steak Consumer and Descriptive Sensory Attributes

Beef flavor attributes of USDA Top Choice and Select beef top loin steaks were evaluated that differed in thickness (1.3 or 3.8 cm) and grill surface temperature (177 or 232°C) when cooked on a commercial flat top grill. A trained descriptive attribute panel and consumer sensory panels were used to evaluate steak flavor and texture. As thickness and temperature increased, beef identity and brown/roasted flavor aromatics increased (P &lt; 0.05). Steaks cooked at 232°C and cut 3.8-cm thick had the highest (P &lt; 0.05) levels of burnt flavor and bitter basic tastes. Thicker steaks cooked at 177°C had more intense umami basic taste and beef identity (P &lt; 0.05). Steaks cut 1.3 cm had lower levels of beef identity and brown/roasted flavor aromatics and the thin cut steaks cooked at 177°C had more sour basic taste (P &lt; 0.05). Consumers rated 232°C, 3.8 cm steaks lowest (P &lt; 0.05) for overall, beef flavor, overall flavor, and grilled flavor liking; whereas, the 177°C, 3.8 cm steaks were highest (P &lt; 0.05) in beef flavor liking. Beef identity, brown/roasted, bloody/serumy, fat-like, umami, sweet, salty, overall sweet, overall tenderness, and muscle fiber tenderness were positive attributes, and metallic, bitter, and burnt were negative attributes in predicting consumer overall liking. Thick steaks cooked at low temperatures or thin steaks cooked at high temperatures resulted in more positive sensory panel traits and consumer liking scores.

Metabolomic Predictors for Flavor Potential of Beef Steaks Differing in Quality Grade, Aging Time, and Degree of Donenesss

ObjectivesThe objective of this project was to explore metabolomic predictors that could determine the potential of beef strip loin steaks differing in quality grade, aging time, and degree of doneness to develop positive flavors.Materials and MethodsUSDA Select (n = 18) and USDA Upper 2/3 Choice (n = 18) beef strip loins (IMPS 180) were collected from a processing plant. Loins were halved, and each half was wet aged for either 10 or 20 d in a cooler kept at 2°C. After aging, loins were cut into 2.54 cm steaks, individually vacuum packaged and stored in a freezer at –40°C. Prior to cooking steaks were thawed in a 4°C cooler for 12 to 24 h. Steaks were cooked on a flat top griddle set to 204.4°C (± 11.1°C) to one of three degrees of doneness: 63°C (medium rare), 71°C (medium) or 80°C (medium well). A six-member expert trained descriptive attribute panel was trained on 16 major attributes, 4 other attributes, and 3 texture attributes from the beef lexicon for 6 d prior to testing. Panelists were trained to scale each attribute on a sixteen-point intensity scale (0 = none, 15 = extremely intense). Panelists were served two random, representative cubes (1.3 cm × 1.3 cm × steak thickness) from each steak in a plastic souffle cup labeled with a random three-digit code. Panelists were seated in a breadbox-style booth under red lighting to eliminate degree of doneness bias. Portions from one raw steak from Quality Grade (QG) × aging combination from each loin was used for high performance liquid chromatography (HPLC) analysis. Samples were homogenized and extracted with a water/acetonitrile solution before being filtered. The lipid fraction was removed via solid phase extraction. Samples were then centrifuged and injected into the HPLC. Data was analyzed as a factorial arrangement of a completely randomized design.ResultsUSDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors and were juicier and more tender compared to USDA Select steaks, which were more intense in metallic and bitter flavors (P < 0.05). Steaks aged for 20 d were juicer and more tender than 10-d aged steaks (P < 0.05). However, 20-d aged steaks also had more intense sour, liver-like, and musty earthy/humus flavors and a less intense brown flavor compared to 10 d aged steaks (P < 0.05). Steaks cooked to 80°C had more intense beef identity, brown, roasted, and umami flavors than steaks cooked to a lower degree of doneness (P < 0.05). Steaks cooked to either 63°C or 71°C had more intense bloody, metallic, and sour flavors and are juicier and more tender than steaks cooked to the higher degree of doneness (P < 0.05). The HPLC analysis of raw steak samples indicated a total of 54 compounds appeared in at least 80% of one treatment. Additionally, there were 2 peptides and 1 sugar that were significantly (P < 0.05) upregulated in the Choice, 20-d-aged strip loins. Additionally, 14 compounds were identified that were shared across all four QG × aging combinations. This included 11 peptides, 2 phospholipids, and 1 heterocyclic aromatic hydrocarbon.ConclusionThese compounds could be indications of the potential for steaks to form positive flavor attributes found in USDA Choice steaks and 20-d aged steaks as described by trained panel analysis.

The Thermophysical Properties of Beef Steaks of Varying Quality Grade and Thickness Cooked on Low and High Grill Surface Temperatures

ObjectivesThe ability of an anisotropic (directionally dependent)-multi-component material, such as beef, to conduct heat is highly dependent on protein states, fat content, water content and other variables. It is also widely known that beef composition greatly impacts overall palatability described by juiciness, tenderness, and flavor. Analysis of these properties in beef steaks of varying USDA quality grades and thicknesses cooked on low and high grill surface temperatures will help to elucidate their importance and how they are affected by cooking. Materials and MethodsBeef steaks of USDA Upper 2/3 Choice and Select quality grades were sliced into thick (38.1 mm) and thin (12.7 mm) steaks and cooked until an internal degree of doneness of 71°C was reached on a commercial flat top grill at low (167°C) and high (232°C) surface temperatures. Thermal conductivity and diffusivity were measured simultaneously using a Thermal Constant Analyzer (Hot Disk TPS 500). Viscoelasticity was measured using a rheometer and textural properties were measured using a Textural Profile Analysis instrument. ResultsThe conductivity of Select steaks was found to be greater (P = 0.048) than Upper 2/3 Choice steaks cooked at low heat as compared to there being no difference (P > 0.05) between quality grades when cooked at high heat. Furthermore, enthalpies of sarcoplasmic and actin protein denaturation differed (P = 0.002) between thick and thin steaks cooked at low heat, as compared to no enthalpy change (P > 0.05) between the thicknesses at high heat. These interactions of quality grade with thickness (conductivity) and thickness with surface temperature (sarcoplasmic and actin enthalpy) indicate that surface temperature impacts thermal behavior, dependent on quality grade, while also influencing major protein structures. The viscoelastic behaviors, elasticity (G’) and viscosity (G”), of the surface and centers of the beef steaks were analyzed to determine how the microstructure of the beef responded to applied stress. The elastic behavior of steak surface and center samples differed due to quality grade dependent on thickness (surface; P = 0.012, center; P = 0.023). The viscous behavior of steak center samples was determined to differ between thicknesses and surface temperatures, dependent on quality grade (P = 0.005). These thermal and physical properties may be further explained through instrumental texture profile analysis described by hardness, resilience, adhesion, cohesiveness, springiness and Warner-Bratzler shear force. Hardness, resilience, and chewiness were influenced by grill surface temperature and thickness, dependent on quality grade (P = 0.007; P = 0.033; P = 0.015, respectively). Thin steaks possessed greater cohesiveness (P = 0.038) and shear force (P = 0.007) values. Meanwhile, thin steaks exhibited lower springiness (P = 0.002). Statistical analysis was performed using ANOVA for a split plot design using USDA Quality Grade as the main plot and steak thickness and grill surface temperature factors in the split plot with 5 replications. ConclusionThe measured changes in thermal and physical properties in the beef steaks suggest that the composition, thickness, and cooking parameters impact the microstructure of beef. These findings were confirmed through textural measurements. Future work will explore relationships between these factors and consumer sensory responses.

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.

Determination of volatile aroma compounds in beef using differences in steak thickness and cook surface temperature

Top loin steaks with a United States Department of Agriculture (USDA) grade of Select were cut 1.3cm, 2.5cm, or 3.8cm thick and cooked on a skillet at 177°C, 204°C, or 232°C. Aroma compounds described as fatty, tallow, and oily are highly related to the identity of beef flavor. These compounds are produced in the highest quantity when steaks are cooked either at low temperatures (177°C) or for short periods of time. Whereas, aroma compounds described as roasted, nutty, or fruity are developed from browning the surface of the steak as a result of cooking at high skillet surface temperatures (232°C) or for long periods of time, as would be seen cooking thick steaks (3.8cm). This study shows that the amount of specific aroma compounds can be predicted (r2 values up to 0.62) from measured cooking times and temperatures. It may be possible to develop beef steak flavor by recommending steak thickness and cooking temperatures.

Flavor and tenderness descriptive attributes in steaks with different steak thickness, quality grade and cooking surface temperatures

Flavor and tenderness descriptive attributes in steaks with different steak thickness, quality grade and cooking surface temperatures

Changing beef strip steak volatile aroma chemical production by differing steak thickness and cook surface temperature

Changing beef strip steak volatile aroma chemical production by differing steak thickness and cook surface temperature

Consumer selection of constant-weight ribeye, top loin, and sirloin steaks

Constant-weight ribeye, top loin, and sirloin steaks were collected from beef carcasses (n = 25) representing five weight/loin muscle area (LMA) groups: G1 (226.8–271.7 kg; 70.97–78.96 cm 2), G2 (272.2–317.1 kg; 78.71–85.81 cm 2), G3 (317.5–362.4 kg; 86.45–93.55 cm 2), G4 (362.9–407.8 kg; 800 cwt, 94.19–101.29 cm 2), and G5 (408.2–453.1 kg; 101.94–109.03 cm 2). Consumers (n = 316) selected 3 steaks of each type and ranked selection criteria (color, marbling, thickness, texture). Consumers selected ribeye steaks from G5 most frequently ( P = 0.0002), but there were no differences among HCW/LMA groups for top loin or sirloin steaks. Thickness was the primary criterion for sirloins and top loins, but marbling was the primary criterion for ribeyes. Data indicate that consumers have preferences for steak thickness and appearance, but the preferred characteristics differ among consumers.