Steak Samples Research Articles

Three liquid phase membrane extraction method based on the electro-migration assisted by high-performance liquid chromatography for the analysis of carcinogenic heterocyclic aromatic amines in steak samples

Three liquid phase membrane extraction method based on the electro-migration assisted by high-performance liquid chromatography for the analysis of carcinogenic heterocyclic aromatic amines in steak samples

The Impact of Storytelling about an Innovative and Sustainable Organic Beef Production System on Product Acceptance, Preference, and Satisfaction.

Food labels and storytelling are marketing tools used by the food industry to highlight and communicate important product characteristics to consumers. By using these tools, food companies can influence consumers' attitudes toward the product and potentially the likelihood of purchase. In the present study, we investigated how storytelling about an innovative and sustainable organic beef production system influenced participants' preference and acceptance of a veal steak product and, further, if some information characteristics were more important than others for consumer satisfaction. Without being aware that the samples were identical, participants (n = 224) tasted two veal steak samples: one steak sample was presented with information about the production system, and the other without information. Results showed that when the steak sample was presented with product information, compared to without information, it received significantly higher hedonic ratings (overall liking, liking of flavor, and liking of texture). This was likewise reflected in a greater preference for the steak sample when presented with product information. Furthermore, product information was found to positively impact the participants' satisfaction with the steak sample regardless of their preference. Overall, our results suggest that the use of storytelling about the innovative and sustainable product system for veal steaks can positively influence consumers' attitudes toward the product.

Assessment of beef sensory attributes and physicochemical characteristics: A comparative study of intermediate versus normal ultimate pH striploin cuts

The quality of beef, defined by key attributes such as the intrinsic sensory qualities texture, flavour, and juiciness, is shaped by various intrinsic and extrinsic factors. This study conducted a detailed examination of Nellore beef, focusing on two categories based on ultimate pH (pHu) levels: intermediate (pHu ≥ 5.8) and normal (pHu < 5.6) beef. A comprehensive approach was taken, involving twenty trained assessors who applied the Optimised Descriptive Profile (ODP) method to evaluate grilled striploin steak samples. In parallel, consumer preferences were measured through a hedonic test and a Check-all-that-apply (CATA) task, involving 135 participants. The ODP results revealed that the intermediate pHu samples were juicier (P < 0.05) compared to the normal pHu group. The CATA analysis highlighted differences in both intermediate and normal pHu beef, especially in juiciness, a crucial factor for consumer satisfaction. Notably, variations in deoxymyoglobin content linked to ageing were observed, with higher levels at the 3rd day compared to the 28th day, especially in the intermediate pHu samples (P < 0.05). Moreover, colour-related aspects such as L*, b*, chroma (C*), and oxymyoglobin were significantly influenced (P < 0.05) by both the pHu category and ageing time. Regarding consumer acceptance, the study found no significant difference in perception between the intermediate and normal pHu groups (P > 0.05). These findings revealed the complex interactions between pHu levels, sensory characteristics, and consumer preferences in beef quality, offering valuable insights for both the industry and research community.

Improving the textural and microstructural quality of cow meat by black chokeberry, grape, and hawthorn vinegar-based marination.

This study was designed to investigate the effects of vinegar-based marinades on pH, technological properties, color, microstructure, texture, and sensory characteristics of 9-year-old Holstein meat which had tough texture. To marinate the Longissimus lumborum steaks, three different marinades were prepared depending on the different additions of vinegar: black chokeberry (BV), grape (GV), and hawthorn vinegars (HV). The group with water (without vinegar) was prepared as a control sample (C). The steak samples were dipped into the vinegar-based marinades and stored at 4°C for 24 h. Vinegar-based marinades decreased the pH and cooking loss of the samples (p < .05). The highest a* values were determined in the BV group, while the samples marinated with vinegar-based marinades had lower L* values than the control group (p < .05). The samples marinated with grape vinegar marinade had the lowest hardness, WBSF, and WBSE values (p < .05). SEM images and sensory analysis results also supported these texture results. The results suggest that grape vinegar-based marinade may be a promising natural tenderizer to improve textural characteristics of tough meats.

Productive and physiological responses of feedlot cattle receiving different sources of Ca salts of fatty acids in the finishing diet.

This study evaluated productive and physiological responses in feedlot cattle receiving a finishing diet that included Ca salts of palm oil (CSPALM), or a blend of Ca salts of palm, cottonseed, and soybean oils (CSMIX). Ninety yearling steers were housed in 15 pens equipped with Calan-gate feeders (6 steers/pen). Steers within each pen were stratified by shrunk body weight (BW; 410 ± 3.3 kg across pens) on d 0 and assigned to receive a total-mixed ration (TMR) containing (dry matter basis) 2.2% of CSPALM (n = 30), 2.2% of CSMIX (n = 30), or no supplemental fat (CON; n = 30). Individual TMR intake was evaluated weekly. Blood samples were collected on d 0, 28, 56, 91, 119, and 147. Samples of the Longissimus muscle (LM) were collected on d 84 via biopsy. Upon slaughter on d 148, hot carcass weight (HCW) was recorded to estimate final BW (63% dressing), and one LM steak sample (2.54 cm thickness) was removed from the right side of each carcass. Steer ADG was greater (P = 0.02) for CSMIX compared with CSPALM and tended to be greater (P = 0.09) for CSMIX compared with CON. The gain:feed ratio was greater (P ≤ 0.05) for CSMIX compared with CSPALM and CON, and carcass LM area was less (P = 0.01) for CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.21) for TMR intake, final BW, and other carcass merit traits including marbling. Mean plasma cholesterol concentrations were greater (P < 0.01) in CSMIX and CSPALM compared with CON, and mRNA expression of adipocyte fatty acid binding protein in the LM on d 84 was greater (P ≤ 0.04) in CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.15) for plasma concentrations of glucose, insulin, insulin-like growth factor I, and leptin, nor for other LM genes associated with marbling and muscle growth. Concentrations of total fatty acids (FA) in plasma and LM steak samples were greater (P < 0.01) in CSMIX compared with CSPALM and CON, and greater (P < 0.01) in the LM samples of CSPALM compared with CON. Steers receiving CSMIX had greater (P < 0.01) concentrations of polyunsaturated and ω-6 FA in plasma and LM steak samples compared with CSPALM and CON. Supplementing CSMIX improved gain efficiency and FA profile in the LM of feedlot steers compared with the CON diet, but the same responses were not observed when CSPALM was offered. Perhaps the advantages from CSMIX supplementation resulted from increasing the supply of polyunsaturated and ω-6 FA to the finishing diet.

Investigation of Microbial Contamination of Rare, Medium, and Well-Done Beef Steak Samples

Investigation of Microbial Contamination of Rare, Medium, and Well-Done Beef Steak Samples

Improvement of the shelf life of grey mullet (Mugil cephalus) fish steaks using edible coatings containing chitosan, nanochitosan, and clove oil during refrigerated storage

The effects of edible coatings made of chitosan, or chitosan nanoparticles, and their combinations with clove oil on the physical, chemical, microbiological, and sensory properties of grey mullet (Mugil cephalus) steaks during refrigerated storage (4 °C) for 24 days were evaluated. The data indicated that metrics for all of these characteristics were improved significantly (P ≤ 0.05) in coated fish steak samples compared to the control sample. The coated steaks texture values were higher than those of control sample through storage time with nanochitosan coating containing clove oil having best value 2.51 kg/cm2 among tested samples at the end of storage period. However, pH values of coated samples were lower, a good indicator, than corresponding one of the control (6.46) with nanochitosan coatings with or without clove oil showed low mean values (6.11–6.13). Similar trend regarding chemical indices, i.e. total volatile basic-nitrogen, trimethylamine, peroxide, and thiobarbituric acid reactive substances values for samples coated with nanochitosan with or without clove oil giving better lower values than control or other treatments. Also, the coating delayed microbial (aerobic plate count, psychrotrophic bacteria, yeasts and molds, and total coliform bacteria) growth during the refrigeration storage period, and coated samples produced better results compared to the control sample. Sensory evaluations showed that the treatment enhanced the scores of fish steak samples compared to the control. The results showed that a nanochitosan coating with clove oil was the best treatment prolonged the shelf life of mullet steaks and efficiently maintained the quality attributes to an acceptable level during refrigerated storage for 24 days. Thus, these findings can be bases for producer to provide consumers with fresh fish steaks with good shelf life at refrigerated temperature for up to 24 days.Graphical

Physical properties during a 28-day ageing period of blesbok (Damaliscus pygargus phillipsi) Longissimus thoracis et lumborum and Biceps femoris muscles

The study aimed to determine the effect of sex, muscle-type, and ageing on the physical properties of blesbok (Damaliscus pygargus phillipsi) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscles. Randomly assigned steak samples from twenty mature blesbok (10 of each sex) antelope were vacuum-packed and stored at 4.4 ± 1 °C for 2, 4, 7, 10, 17 and 28 ageing days. Cumulative purge loss, pH, colour (L*, a*, b), cooking loss, and Warner Braztler shear force were determined. Males had meat with higher (P = 0.032) pH values than females, while all other attributes were similar (P > 0.05). The LTL had greater (P < 0.05) purge losses, L* and a* values than the BF muscle, while other quality attributes were greater (P < 0.05) for the BF muscle. Despite fluctuations, there was an overall decrease in shear force with ageing time. According to all quality parameters measured, the optimum ageing period for blesbok would seem to be 10 days.

Portable vibrational spectroscopic methods can discriminate between grass-fed and grain-fed beef

The present study analysed the ability for portable near infrared reflectance (NIR) and Raman spectroscopy sensors to differentiate between grass-fed and grain-fed beef. Scans were made on lean and fat surfaces of 108 beef steak samples labelled as grass-fed ( n = 54) and grain-fed ( n = 54), with partial least squares discriminant analysis (PLS-DA) and linear discriminant analysis (LDA) used to develop discrimination models which were tested on independent datasets. Furthermore, PLS-DA was used to predict visual marbling score and days on feed (DOF). The NIR spectra accurately discriminated between grass- and grain-fed beef on both fat (91.7%, n = 92) and lean (88.5%, n = 96), as did Raman (fat 95.2%, n = 82; lean 69.6%, n = 68). Fat scanning using NIR spectroscopy moderately predicted DOF (r2val = 0.53), though Raman and NIR spectroscopy lean prediction models for DOF and marbling were less precise (r2val &lt; 0.50). It can be concluded that portable NIR and Raman spectrometers can be used successfully to differentiate grass-fed from grain-fed beef and therefore aid retail and consumer confidence.

Cyclic strand displacement polymerase reaction to turn-on molecular beacons for rapid detection of Staphylococcus aureus

Staphylococcus aureus (S. aureus) is one of the most common food-borne pathogens, and its rapid detection is important for food safety. In this paper, a method for rapid detection of S. aureus by using cyclic strand displacement polymerase reaction (CSDPR) for turn-on molecular beacons (MBs) was proposed. The highly conserved 16S rDNA fragment sequence of S. aureus was screened as the target nucleic acid, and was detected by CSDPR amplification. Under the optimized condition, the linear range of the method was 2.0 × 105–2.5 × 106 CFU/mL, and the detection limit was 9.5 × 104 CFU/mL. The reaction time of CSDPR was 15 min. This method has been applied to the rapid detection of S. aureus in spiked milk and steak samples and the detection results are consistent with those of plate counting method.

Detection of Volatiles from Raw Beef Meat from Different Packaging Systems Using Solid-Phase Microextraction GC-Accurate Mass Spectrometry.

The volatile profile of raw beef contains vital information related to meat quality and freshness. This qualitative study examines the effect of packaging system on the formation and release of volatile organic compounds (VOCs) from raw beef over time, relative to the packaging best before date (BBD). The three packaging systems investigated were modified atmospheric packaging, vacuum packaging, and cling-wrapped packaging. Porterhouse steak samples with the same BBD were analysed from 3 days before to 3 days after the BBD. VOCs were detected via preconcentration using solid-phase microextraction combined with gas chromatography–accurate mass quadrupole time-of-flight mass spectrometry. In total, 35 different VOCs were tentatively identified. Interestingly, there was no clear relationship of the VOCs detected between the three packaging systems, with only carbon disulphide and acetoin, both known volatiles of beef, detected in all three. This is the first study to investigate the effects of commercial packaging systems on VOC formation; it provides an understanding of the relationship of VOCs to the BBD that is essential for the development of on-pack freshness and quality sensors.

Palatability of high-quality New Zealand grass-finished and American grain-finished beef strip steaks

The objective of this study was to evaluate palatability of strip loin steaks from grass- and grain-fed beef across five United States Department of Agriculture (USDA) quality grades and three wet aging periods. Beef strip loins (N = 200; 20 per USDA quality grade/fed cattle type) representing five USDA quality grades [USDA Prime, Top Choice (Average and High Choice), Low Choice, Select and Standard] and two fed cattle types [New Zealand grass-finished and United States (U.S.) grain-finished] were used in the study. Each strip loin was equally portioned into thirds and randomly assigned to one of three wet aging periods (7 d, 21 d or 42 d). Consumer panelists (N = 600; 120/location: Texas, California, Florida, Kansas, and Pennsylvania) evaluated eight grilled beef steak samples for palatability traits, acceptability, and eating quality. All palatability traits were impacted by the interaction of diet × quality grade (P &amp;lt; 0.05). Although similar (P &amp;gt; 0.05) to grass-fed Prime steaks for juiciness, tenderness and overall liking, grain-fed Prime steaks rated greater (P &amp;lt; 0.05) than all other grass- and grain-finished treatments for all palatability attributes. Grass-finished Top Choice, Low Choice, and Standard steaks were rated greater (P &amp;lt; 0.05) than the respective grain-finished quality grades for juiciness and tenderness. Grain-finished Standard steaks rated lower (P &amp;lt; 0.05) than all other grass- and grain-finished treatments for juiciness, tenderness, and overall liking; but were similar (P &amp;gt; 0.05) to grass-finished Standard steaks for flavor liking. Our results indicate beef strip loin steaks of similar quality grades from grass-finished New Zealand cattle produce similar eating experiences when compared to those from U.S. grain-finished beef, even following extended post-mortem aging. This indicates improved palatability for consumers based on marbling without respect to grass- or grain-finishing diets.&amp;nbsp;

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

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

250 Evaluation of Green Grass as a feed ingredient in beef finishing rations and impact on cattle performance, carcass characteristics, and fatty acid profiles in meat

Abstract A finishing study used 240 crossbred steers (initial BW=340 ±24 kg) to evaluate performance, carcass characteristics, and fatty acid profiles of beef from finishing steers. Four inclusions (0, 10, 20, 30 % DM basis) of Green Grass displaced dry rolled corn in the finishing diet. Green Grass is a blend of herbs and plants imported from Korea that are high in omega-3 fatty acids with 13.9 % fat,32.0 % CP, and 27.0 % Acid detergent fiber. The remaining diet consisted of 15 % WDGS, 20 % corn silage, and 6 % liquid supplement (DM basis). There were no differences in final BW, gain or carcass traits (P³0.14). Cattle were harvested over three slaughter days and were fed for 190, 199, or 203 days. Dry matter intake linearly increased (P = 0.04)as Green Grass inclusion increased in the diet. A linear response (P£0.01) to feeding Green Grass was observed for G:F, with steers fed Green Grass having lower feed efficiency than control cattle. The G:F of cattle fed Green Grass was 5.4, 3.4, and 6.8 % lower in G:F as inclusion increased suggesting Green Grass has 68.6 % the energy of corn it replaced. Steers fed 30 % Green Grass had a lower marbling score. Linear increases in alpha linolenic acid, trans-unsaturated fatty acids, and omega-3 fatty acids (P£0.01) were observed in steak samples from steers fed increasing inclusion of Green Grass. Including up to 30 % inclusion of Green Grass on a DM basis in finishing diets decreased G:F; however, it appeared to have no other effects on performance or carcass characteristics. Feeding Green Grass linearly improved omega-3 fatty acid concentration in beef.

Statistical Analysis of GC/MS Data from Beef Steaks Cooked with Different Grill Temperatures and Steak Thicknesses Containing Missing Values, Lacking Normal Distributions, or Unequal Variance

ObjectivesOur objectives were to determine the degree of normality in selected volatile compound samples, the improvement to normality transformations may make, and the changes in interpretation transformations could induce.Materials and MethodsBeef strip loins (n = 32) were sliced 3.81 or 1.27 cm thick. Steaks were cooked on an electric flat grill set at either 176°C or 232°C to an internal cook temperature of 71°C. Cubes (1.27 square) were transferred to a 470 mL glass jar and the static headspace was collected with SPME for 2 h. The SPME was injected into a multi-dimensional GC/MS identification of volatile aroma compounds. Volatiles were selected with a MS quality score above 75 and occurred in a minimum of 10% of the total steak samples. Absence of an observation for a volatile compound may be due to treatment effect, instrumentation limits, or simply missing from the sample. To analyze the normality of volatiles, representative volatiles selected were benzaldehyde, methyl-pyrazine, nonenal, and 2-octanone, as they were present in 95, 63, 42, or 20% of the total steak samples, respectively. These selected volatiles were then subjected to square root, log10, or Box-Cox transformations. If a volatile was absent in a steak sample, that cell was designated as either a missing value (MV) or as a zero (0). Shapiro-Wilk, box-plot, and normality distribution plots were used to measure normality for each of the volatiles across all conditions. Brown-Forsythe and Bartlett’s tests were used to determine homogeneity of variance.ResultsVolatiles designated as a zero when no GC total ion counts (TIC) were present had residuals within treatment cells that were not normally distributed (P &lt; 0.05). Volatile compounds nonenal and 2-octanone were normally distributed (P &gt; 0.05) when empty cells were designated as MV, but benzaldehyde and methyl-pyrazine were not (P &lt; 0.05). Square-root transformation of the data resulted in all the data designated with MV to be normally distributed (P &gt; 0.05) while data with empty cells designated with 0 were unchanged and not normal (P &lt; 0.05). Furthermore, Box-Cox transformations of MV data had lambda values of 0.23, 0.11, 0.18, and 0.10 for benzaldehyde, methyl pyrazine, nonenal, and 2-octanone, respectively. Brown-Forsythe and Bartlett’s test indicated that as the percentage of volatiles present decreased, the treatment mean responses became less homogeneous in their variance (P &lt; 0.05) as indicated by the fact that only benzaldehyde upheld the assumption of homoscedastic behavior (P &gt; 0.05).ConclusionAnalysis of volatile aroma compounds from cooked beef results in numerous missing values in the data, and by nature the data are not normally distributed, nor do they have homogenous variance as a result. Analyzing data with missing values rather than zeroes improves normality and additionally, transformation of the data using square root or Box-Cox significantly improved normality but had only minor impact on homogeneity of variance. ANOVA F-ratios were consistently highest on data that were entered with missing values rather than zeroes and were not transformed. Care should be taken analyzing volatile GC data to take into account the basic assumptions regarding the data and steps can be taken to conform to those assumptions.

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.

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.

Evaluating the Relationship of Animal Temperament to Carcass Characteristics and Meat Quality

The purpose of this study was to compare meat quality and sensory characteristics of steaks from longissimus dorsi of steers with different temperaments. Calves (n = 49; 314kg) were processed and scored for temperament according to Beef Improvement Federation Guidelines and divided into three groups: Docile (D), Restless (R) and Nervous-Flighty (NF). Steers were housed with access to pasture then transferred to a research feedlot until harvest and processed with carcass data recorded. Striploins were wet-aged for 14 d before, frozen and were then cut into 2.54 cm steaks, and individually vacuum packed. Instrumental color was measured on thawed and tray overwrapped steaks on d 0, 1, 2, 3, 5, and 7 of simulated retail display. The CIE L*, a*, and b* color values were collected and oxymyoglobin, hue angle and saturation index values were calculated. A 7-member trained sensory panel evaluated steak samples for myofibrillar tenderness, connective tissue amount, overall tenderness, juiciness, and beef flavor intensity. The NF group had reduced (P &lt; 0.05) hot carcass weight compared to the other groups. The D and R groups were lighter (L*; P &lt; 0.05), and R group yellower (b*; P &lt; 0.05) and greater (P &lt; 0.05) in hue angle than the other groups. No difference (P &gt; 0.05) between groups for redness (a*), saturation index, and oxymyoglobin ratio were observed. Display time affected color with d 0 being redder (a*; P &lt; 0.05), yellower (b*; P &lt; 0.05), greater (P &lt; 0.05) saturation index, and greater (P &lt; 0.05) oxymyoglobin ratio than d 7. Steaks from D and R groups were more tender (P &lt; 0.05) in myofibrillar tenderness, had less (P &lt; 0.05) perceived connective tissue, were overall more tender (P &lt; 0.05), and more (P &lt; 0.05) juicy than steaks from the NF group. There was no difference (P &gt; 0.05) in off-flavor between the temperament groups. Temperament had minimal effect on carcass characteristics except hot carcass weight. Sensory panelists detected differences between temperament groups.

Lipid Oxidation of American Grain-Fed and New Zealand Grass-Fed Strip Loins Varying in Aging Time and Marbling Level

ObjectivesGrass-fed beef imported from New Zealand has been known to be lower in fat content and undergo a longer wet-aging period during transport compared to domestically produced beef. The effects of wet-aging time on oxidative metrics in highly marbled grass-fed beef are not fully known at this time. Therefore, the objective of this research was to assess the lipid stability of grass-fed strip loin steaks in comparison to grain-fed strip loin steaks from 5 different United States Department of Agriculture (USDA) quality grades, wet-aged for 7, 21, and 42 d.Materials and MethodsBeef strip loins (n = 200) representing 2 fed cattle types (n = 100/finishing type: grass-finished and grain-finished) and 5 different USDA quality grades (n = 20 per quality grade: USDA Standard, Select, Low Choice, “Top” Choice: High and Average Choice, and Prime) were acquired from beef processing facilities in New Zealand (grass-fed) and Nebraska (grain-fed). Each strip loin was equally portioned into thirds, vacuum packaged, and assigned to 1 of 3 wet aging periods (7, 21, or 42 d). After the appropriate aging period, portions (n = 600) were frozen and stored at the Gordon W. Davis Meat Science Laboratory until further fabrication. Frozen strip loin portions were cut into 2.54 cm steaks using a band saw. Prior to cutting portions into steaks, steak samples for thiobarbituric acid-reactive substances (TBARS) were taken from the anterior and posterior face steaks of each strip loin portion. The steak pieces for TBARS analysis were vacuum packaged and frozen until homogenization. Samples were thawed for 12 to 24 h, trimmed of subcutaneous fat and connective tissue, frozen in liquid nitrogen and homogenized for TBARS analysis. The amount of TBARS was determined to estimate lipid oxidation, and results were reported in mg malondialdehyde/kg sample. Statistical analyses were conducted using the procedures of SAS (Version 9.3; SAS Inst. Inc., Cary, NC). Treatment comparisons were tested for significance using PROC GLIMMIX with ɑ = 0.05.ResultsA diet by age time interaction was found for TBARS values (P < 0.05). No difference was found between grass-fed 7, 21, or 42 d treatments for TBARS (P > 0.05), indicating prolonged aging periods had no detrimental effect on grass-fed strip loins. Whereas, grain-finished strip loins aged 42 d had greater TBARS values than shorter aged product (P < 0.05). All grain-finished strip loins, regardless of age, had higher TBARS values than all grass-finished strip loins (P < 0.05). Finally, no difference was found between quality grades for TBARS (P > 0.05). The TBARS values for all samples were low, ranging from USDA Standard at 0.098 mg/kg to USDA Low Choice at 0.111mg/kg.ConclusionIn conclusion, all steaks had very low levels of lipid oxidation, due to aging in a vacuum package. Although lipid oxidation tended to increase with longer periods of wet-aging time, steaks from grass-fed cattle were less susceptible to lipid oxidation than grain-fed cattle.

Effects of liver abscess severity and quality grade on meat tenderness and sensory attributes in commercially finished beef cattle fed without tylosin phosphate.

Strip loin steaks (n = 119) were used to evaluate the association between liver abscess severity and USDA quality grade and meat tenderness and sensory attributes of steaks from finished feedlot cattle. Steaks were used in a 3 × 2 factorial treatment structure using a completely randomized design and were collected at a commercial abattoir located in northwest Texas. All cattle were sourced from a single feedlot and fed a common diet that did not include tylosin phosphate. Treatments were USDA quality grades of Select (SEL) and Low Choice (LC) and liver abscess scores of normal (NORM; healthy liver, no abscesses), mild (M; 1 abscess less than 2 cm in diameter to 4 abscesses less than 4 cm in diameter), and severe (SV; 1 abscess greater than 4 cm in diameter or greater than 4 small abscesses). All steak samples were collected on the same day, approximately 36-h post-mortem and were cut from the left side of the carcass at the 13th rib by a trained abattoir employee. Steaks were vacuum-packaged, and aged at 3 ± 1°C for 14-d post-mortem. Warner-Bratzler Shear Force (WBSF) and Slice Shear Force (SSF) analyses were conducted and cook-loss percentage was measured. A trained sensory panel analyzed samples for juiciness, tenderness, and flavor attributes. There were no differences among liver abscess scores for WBSF or SSF (P > 0.52). Warner-Bratzler Shear Force was lower for LC-SV than SEL-SV (P = 0.04). Sensory attributes of initial and sustained juiciness, and overall tenderness were all greater for LC than for SEL steaks (P < 0.04) and connective tissue amount was less for LC steaks when compared to SEL (P = 0.03). Liver abscess score had no effect on any sensory attributes (P > 0.70); however, there was an interaction between quality grade and liver score for myofibillar tenderness (P = 0.03). Within LC steaks, liver abscess score had no effect on myofibrillar tenderness (P > 0.05), however, in SEL steaks, M steaks were more tender than SV steaks (P < 0.03). These results indicate that within quality grades, meat tenderness or sensory attributes were not influenced by liver abscess score but that mild liver abscesses may affect the myofibrillar tenderness of SEL steaks.