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This study was designed to determine whether exposure to low-dose endotoxin (lipopolysaccharide; LPS) during gestation can enhance immunity to a subsequent LPS challenge in piglets after weaning. Pregnant sows (parity: 2.6 ± 1.4) were assigned to prenatal immune stimulation (PIS; n = 7; administered 2.5 µg/kg BW LPS, i.m.) or saline treatment groups (CON; n = 7) administered at day 78 ± 1.8 of gestation. From the two prenatal treatment groups, barrows (n = 17 PIS, 17 CON) were identified at weaning (21 ± 1.3 day of age) to subsequently receive a post-weaning LPS challenge. On day −1, the pigs were fitted with indwelling jugular catheters and subcutaneous temperature loggers. On day 0, the pigs were challenged i.v. with LPS (10 µg/kg BW), and blood samples were collected at −2, 0, 1, 2, 4, 6, 8, 12, and 24 h relative to LPS challenge. There was a treatment × time interaction for subcutaneous temperature (P < 0.01), where the temperature increased more quickly at 1 and 2 h post-challenge in PIS compared to CON pigs. There was a tendency (P = 0.08) for less change in white blood cells, relative to baseline values, in PIS compared to CON pigs. There was a treatment × time interaction (P = 0.01) for lymphocyte concentrations where the concentrations were reduced in PIS compared to CON pigs at 8 h post-challenge. There was also a treatment × time interaction (P = 0.01) for the change in eosinophil concentrations, where there was less change in eosinophil concentrations from 1 to 12 h in PIS compared to CON pigs. There was a tendency (P ≤ 0.06) for a treatment × time interaction for serum interleukin-6 (IL-6) and IL-8. Granulocyte-macrophage colony-stimulating factor tended to be greater, and tumor necrosis factor-α tended to be reduced in PIS compared to CON pigs (P ≤ 0.08). These data suggest that exposure to endotoxin in utero may influence the postnatal innate immune response to endotoxin. More research is necessary to further understand the mechanism behind the differences observed and the potential long-term influence of prenatal immune stimulation on pig offspring.

This study evaluated the effects of dry-aged beef trimmings inclusion on quality and flavor precursors of ground beef patties. Lean and fat trim were collected from beef loins aged for 28 d using 4 different methods: wet aging (WA), dry aging (DA), dry aging in water-permeable bag (DWA), and UV-light dry aging (UDA). Trimmings were ground and incorporated with ground fresh beef top rounds and subcutaneous fat (3 d postmortem) to make patties (80% lean and 20% fat) with different formulations: fresh beef and fat (CON), fresh beef and DA fat only (DA-FAT), and mixtures of 50% fresh lean along with 30% aged lean and 20% aged fat from different aging treatments (WA, DA, DWA, and UDA). Patties were manufactured in 3 independent batches (n = 3) to conduct pH, cooking loss, texture analysis, lipid oxidation, 5 d aerobic display color, trained sensory evaluation, volatile compounds, and metabolomics analyses. The inclusion of aged beef trimmings did not impact the pH and cook loss of the patties (P > 0.05). DWA trimmings lowered chewiness compared to CON (P < 0.05) and induced greater product discoloration compared to all other treatments at the end display (P < 0.05). The addition of DA and UDA trimmings in ground beef reduced bloody flavor and promoted more volatile production compared to other treatments (P < 0.05). Metabolomics profiling revealed different flavor precursor profiles from the inclusion of trimmings aged differently, demonstrating that the addition of the lean trim portion influenced the flavor profile more significantly than the fat trim portion after cooking. Cooking significantly altered the metabolite profile, reducing variations between the different treatments and explaining the observed flavor changes. The results suggested that aged trimmings modify the flavor precursor profile in ground beef products. Further research to identify the impact of different cooking methods on the flavor generation potential of dry-aged trimming inclusion products would be beneficial.

Six muscle-specific ground beef products along with conventional chuck ground beef were evaluated for proximate composition, objective color, descriptive flavor attributes, texture attributes, fatty acid composition, and volatile com- pound profile. Ground products were derived from beef chuck shoulder clods, chuck boneless short ribs, whole briskets, loin tenderloin tips, loin top sirloin caps, round sirloin tip knuckles, and 81:19 chuck-sourced trimmings. Each grind type was formulated to a target fat percent of 15%. Proximate analysis determined actual fat content to range from 12.0% to 19.5%. Percent fat was tested as a covariate and included in model statements when significant. Sirloin caps, brisket, and 81:19 chuck each had greater beefy/brothy ratings compared with shoulder clods and tenderloins (P < 0.05). Tenderloin grinds also had lower browned/grilled, buttery/beef fat attributes compared to all others (P < 0.05). Additionally, tenderloins had greater sour/acidic flavor compared to all others (P < 0.05). Oleic acid (C18:1 cis-9) percent was lower in tenderloin compared to all others (P < 0.05). Percent C18:1 cis-9 of 81:19 chuck was comparable with short rib and sirloin cap grinds (P > 0.05) but lower than shoulder clods, brisket, and knuckles (P < 0.05). Tenderloin grinds had the greatest percent of stearic acid (C18:0) compared to all others (P < 0.05). Tenderloin grinds also expressed the greatest content of 1-hexanol, hexanal, acetic acid, and 3-methylbutanal (P < 0.05). Methional content was greater from 81:19 chuck compared to all others (P < 0.05). Likewise, the knuckle had greater dimethyl sulfide compared to all other grinds (P < 0.05). Interestingly, short rib grinds frequently had the lowest (P < 0.05) or were comparable (P > 0.05) with other grinds low in the quantity of multiple volatile compounds. The results of this study imply that muscle source influences flavor and flavor-related compounds of ground beef. Therefore, processors and retailers may manage muscle sources and thus ground beef flavor through subprimal selection.

The objective of the study was to evaluate the effects of chromium (Cr) and methionine on myogenic gene expression, GLUT4 and insulin receptor (IR) synthesis, and amino acid uptake in differentiated bovine satellite cells. Cells were treated with 0, 1, or 10 μM of chromium acetate (CrAc) and 0, 1, or 10 mg/mL of methionine, with cells utilized for the amino acid assay receiving 0.1 μM instead of 1 μM of CrAc. The addition of 10 μM of Cr tended to downregulate AMPKα mRNA gene expression (P < 0.1). Myogenin was impacted by methionine and CrAc with high doses and low doses upregulating expression (P < 0.01). The ratio and protein levels of AMPKα to pAMPKα, GLUT4, and IR abundance were not affected (P > 0.1). Increase in time decreased concentrations of leucine, isoleucine, threonine, methionine, phenylalanine, glutamine, ornithine, lysine, and cysteine (P < 0.01) in conditioned media. Over time, alanine increased (P < 0.01). Methionine inclusion increased alanine, proline, glutamic acid, ornithine, and tryptophan concentrations, as well as decreased leucine, isoleucine, and cysteine (P < 0.01). CrAc only affected glutamine and tryptophan, which both increased with CrAc dose, whereas alanine decreased (P < 0.01). Methionine decreased over time within the 10 mg/mL group (P < 0.01). Tryptophan was generally unaffected but decreased in the 0 mg/mL group at 48 h. Cysteine decreased with a decreased dosage of CrAc at 24 h (P < 0.01). Lysine was generally unaffected by this interaction (P > 0.1), with the exception of the 0.1 μM treatment group at 24 h being higher (P < 0.01). CrAc affected the uptake of alanine, glutamine, and tryptophan (P < 0.01). Methionine inclusion increased alanine, proline, glutamic acid, ornithine, and tryptophan, as well as decreased leucine, isoleucine, and cystine (P < 0.01). Increased time saw a significant decrease in leucine, isoleucine, threonine, methionine, phenylalanine, glutamine, ornithine, lysine, and cystine (P < 0.01) and an increase in alanine (P < 0.01).

Forty castrated Holstein calves underwent an adrenocorticotropic hormone (ACTH) challenge to assess the effects of premortem stress on the longissimus lumborum (LL) following harvest. LL biopsies were collected before the challenge, at different harvest times (2, 12, 24, and 48 h; n = 10), and after 14 d aging. The expression of small heat shock proteins (SHSPs), deglycase 1 (DJ-1), and troponin were analyzed. Blood was analyzed throughout the ACTH challenge and at harvest for cortisol, oxidative stress, and complete blood count (CBC). Color and myofibrillar fragmentation index (MFI) were measured in aged samples. Unexpectedly, calves from different harvest times differed (p = 0.05) in cortisol response. Calves were divided into two different cortisol response groups (high or low; n = 20). Statistical analysis assessed the effects of cortisol response (n = 20), harvest time (n = 10), and their interaction. Harvest time altered SHSPs (p = 0.03), DJ-1 (p = 0.002), and troponin (p = 0.02) expression. Harvest time and cortisol response impacted steak color (p < 0.05), and harvest time altered steak pH (p < 0.0001). Additionally, various CBCs were changed (p < 0.05) by harvest time. Harvest time changed (p = 0.02) MFI. These data demonstrate that the protein expression, color, and MFI of the LL may be influenced by premortem stress.

The objective of this study was to understand the influence of USDA quality grade, muscle, and aging duration on ground beef flavor development. Prime (PR), Low Choice, and Standard quality grade beef subprimals were collected and aged for either 21 or 42 d. Following aging, subprimals were fabricated into gluteus medius (GM), biceps femoris (BF),and serratus ventralis (SV) then ground and formed into patties. Raw patties were designated for proximate composition, fractionated fatty acids, and thiobarbituric acid reactive substances (TBARS). Cooked patties were designated for consumer sensory analysis, volatile compound analysis, and TBARS. Patties were cooked on a preheated griddle to 72°C. All data were analyzed as split-split plot where quality grade served as the whole plot factor, muscle as the subplot factor, and aging duration as the sub-subplot factor. Significance was determined at P0.05). Individually, the BF and 42 d aged subprimals had the greatest cooked malondialdehyde concentration (P0.05). The SV produced less Maillard reaction products (P

Beef retail steaks from establishments across 11 US cities and beef foodservice steaks from establishments in 6 US cities were evaluated by consumer sensory evaluations and Warner-Bratzler shear (WBS) force analyses. The retail tenderloin had the lowest (P0.05) differences in WBS force values among USDA quality grade groups for foodservice steaks. Retail tenderloin steaks received the highest (P0.05)differences among the 4 foodservice cuts for consumer sensory ratings of overall like/dislike, tenderness like/dislike, tenderness level, flavor like/dislike, and juiciness like/dislike. There were no (P>0.05) USDA quality grade differences for ribeye, top loin, top sirloin, and tenderloin foodservice steaks for overall like/dislike, tenderness like/dislike, tenderness level, flavor like/dislike, and juiciness like/dislike. Regardless of source (foodservice or retail), USDA grade group, or beef cut, measures of tenderness in this survey reveal ratings and values that should meet most consumer expectations in the marketplace.

The objective of the study was to determine the effect of extended aging on the flavor development of various muscles, individually stored in vacuum rollstock packaging. Strip loins, paired tenderloins, and top sirloin butts (n=48) from USDA Low Choice carcasses (Small00 to Small100 marbling score, n=16). Subprimals were wet-aged in the absence of light for 28 d postmortem before fabrication into 2.54 cm steaks representing the longissimus lumborum (LL), psoas major (PM), and gluteus medius (GM). Steaks were individually packaged in vacuum rollstock packaging and assigned to an additional aging time of 28, 35, 42, 49, or 56 d. Cut steaks (n=240/test) were designated to trained descriptive panel analysis or volatile compound analysis. No interactions occurred for trained sensory analysis, but a main effect of days of age (P≤0.033) showed the greatest effect on negatively associated attributes, including liver-like, oxidized, fishy, bitter, and sour, after 42 d of aging. A main effect of muscle type also occurred (P≤0.040) for flavor attributes, in which GM and PM samples scored higher in off-flavor attributes compared with LL samples, including flavors such as liver-like, oxidized, and sour. An interaction between muscle type and days of age occurred for 2-pentyl-furan (P=0.021). One compound—3 hydroxy-2 butanone—was affected by muscle type (P=0.009). However, most compounds were affected by days of age (P≤0.046), in which compounds related to off-flavors increased in concentrations the most after 49 d. Additionally, discriminant function analyses were performed, suggesting the most effective aging time for individual steaks to be under 49 d when considering loadings for volatile compounds and flavor attributes corresponding with days of age. Overall, these data suggest individual packaging of GM, LL, and PM muscles is most optimal for up to 42 or49 d of age without a large impact from the presence of off-flavors, thus providing food service establishments the opportunity to individually package beef steaks for an extended period while maintaining consumer satisfaction through optimal flavor.

The objective of this study was to evaluate the viability and performance of nitric oxide modified-atmosphere packaging (MAP) as a novel alternative to high oxygen and carbon monoxide MAP for ground beef. Packages of ground beef under high oxygen (HI-OX), carbon monoxide (CO), and nitric oxide (NO) atmospheres were evaluated for descriptive and instrumental color every 12 h during a 120 h display period. Surface myoglobin percentages, internal cooked color, thiobarbituric acid reactive substances (TBARS), and residual nitrite and nitrate were also evaluated. There were gas × time interactions for descriptive color, discoloration, a* values, b* values, deoxymyoglobin percentages, and metmyoglobin percentages (p < 0.05). There were also gas-type main effects for cooked color and TBARS (p < 0.05). Carbon monoxide maintained the most redness and least discoloration throughout the display period, while HI-OX started with a bright red color but rapidly browned (p < 0.05). Nitric oxide started as dark red to tannish-red but transitioned to a dull red (p < 0.05). However, NO had increased redness and a* values for internal cooked color (p < 0.05). Although CO outperformed NO packages, NO exhibited a unique color cycle warranting further research to optimize its use.

The objective of this study was to investigate the influence of beef wet-aging temperature and duration on beef palatability. Paired beef strip loins were obtained from USDA Choice carcasses (n=60) at a commercial processing facility. Paired strip loins were assigned to a storage temperature (−2°C, 0°C, or 4°C). Strip loins were portioned into half loins and further assigned to an aging duration (14, 28, 42, or 56 d). Loins were aged in commercial upright refrigerators.After aging, loins were fabricated into 2.54-cm steaks and assigned to either volatile compound analysis, descriptive sensory analysis, or consumer sensory analysis. Data were analyzed as a split-plot in which carcass served as the whole plot and loin portion served as the subplot. An alpha of P28 d) conducted at colder temperatures did not negatively influence palatability. Aging for 14 d at −2°C was detrimental to consumer liking. It may be concluded that both aging temperature and duration should be considered when seeking to optimize beef palatability.

Beef flavor has been identified as a driver of consumer acceptability; however, little is known about variability of flavor in major United States retail beef cuts. Four beef cuts (chuck roast; top sirloin steaks; top loin steaks; and 80/20 ground beef) were obtained from retail stores (n=30 per cut per city) in Miami, Los Angeles, Portland, New York, and Denver during a 2-mo period in 2018. Production systems or package claims were documented. An expert trained flavor and texture descriptive attribute sensory panel evaluated beef flavors, aromas, and textures (n=10 cuts per city or 50 cuts evaluated). Consumer sensory panels in Fort Collins, CO (n=10 per cut/city), and Lubbock, TX (n=10 per cut/city), evaluated beef for overall liking, overall flavor, beef flavor, grilled flavor, juiciness, and texture liking. Ground beef patties (GB) were more intense (P

The objective of this study was to evaluate palatability of strip loin steaks from grass- and grain-fed beef across5 United States Department of Agriculture (USDA) quality grades and 3 wet-aging periods. Beef strip loins (N=200; 20/USDA quality grade×fed cattle type) representing 5 USDA quality grades (USDA Prime, Top Choice [Average and High Choice], Low Choice, Select, and Standard) and 2 fed cattle types (New Zealand grass-finished and U.S. grain-finished)were used in the study. Each strip loin was equally portioned into thirds and randomly assigned to one of 3 wet-aging periods (7 d, 21 d, or 42 d). Consumer panelists (N=600; 120/location: Texas, California, Florida, Kansas, and Pennsylvania) evaluated 8 grilled beef steak samples for palatability traits, acceptability, and eating quality. All palatability traits were impacted by the interaction of diet×quality grade (P0.05) to grass-fed Prime steaks for juiciness, tenderness, and overall liking, grain-fed Prime steaks rated higher (P0.05) to grass-finished Standard steaks for flavor liking. Our results indicate that beef strip loin steaks of similar quality grades from grass-finished New Zealand cattle produce similar eating experiences when compared with those from U.S. grain-finished beef, even following extended postmortem aging. This indicates improved palatability for consumers based on marbling without respect to grass- or grain-finishing diets.

Phenotypic expression of dairy influence often carries negative implications in beef production; thus, considerable variation in expression of beef- versus dairy-type might adversely affect value of crossbred beef × dairy cattle. This study evaluated effects of phenotype in crossbred beef × dairy cattle, specifically that associated with beef- versus dairy-type, on meat quality. Effects were blocked within commercial feedlot pens because cattle within a pen were contemporaries for sex, age, management, and source. On their harvest date, 592 Angus or [Simmental × Angus] × Holstein cattle from 9 pens were assessed by 3 expert evaluators. Scores for muscling and frame size were used to categorize and subset cattle in a pen into 4 phenotype groups: (1) fully dairy-type, (2) partially dairy-type, (3) partially beef-type, and (4) fully beef-type. Strip loin steaks were obtained from selected cattle (n = 82 to 84 per group) and evaluated for descriptive sensory attributes, shear force, pH, color at retail display, steak dimensions, muscle fiber type, and fatty acid composition. Data were tested for fixed effects of phenotype group with random effects of pen. Despite distinct expression of visual beef- versus dairy-type among cattle sampled, phenotype groups were largely not different (P > 0.05) in shape, sensory attributes, color, or biochemical properties of strip loin steaks. Other body regions, separate from the loin, were likely responsible for differences in live animal muscling. Additional research is needed on effects of sire breed, individual sire, and management strategies on meat quality in beef × dairy crossbreds. Complementarity of beef breeds and sires to produce more profitable beef-type cattle from the beef × dairy mating system should not be expected to negatively influence meat quality. Marketing programs rooted in production of consistent and premium products may benefit from including beef from beef × dairy crossbreds.

The objective of this study was to determine the influence of lighting type and display duration on flavor development in multiple beef muscles. Paired beef top sirloin butts, strip loins, and tenderloins were collected from USDA Low Choice carcasses (Small00 to Small100 marbling score, n=16). Subprimals were wet aged in the absence of light for 7 d postmortem at 0°C to 4°C before being fabricated into 2.5-cm steaks representing the Gluteus medius, Longissimus lumborum (LL), and Psoas major. Steaks were packaged individually in vacuum rollstock packaging and assigned to either light-emitting diode (LED) or fluorescent (FLUR) display cases for a display period of 0, 2, 6, or 10 d. All steaks were assigned to either trained descriptive panel analysis (n=384) or volatile compound analysis (n=384) and cooked to a medium degree of doneness (71°C). Two-way interactions occurred between lighting type and display duration, showing increased tenderness sooner during display for LED steaks, and lower umami intensity in FLUR steaks after 10 d (P

The objective was to evaluate the influence of vacuum-packaged aging temperature, duration, and their inter-action on spoilage organism growth, proteolytic activity, and resulting beef tenderness. Paired strip loins were collected from 60 USDA Low Choice beef carcasses (n=60), then assigned a storage temperature (−2°C, 0°C, or 4°C). Loins were portioned into half loins and assigned to an aging duration (14, 28, 42, or 56 d) and vacuum packaged. Loins were aged in commercial upright refrigerators. Half-loin packages, at their respective aging duration, were aseptically opened and cut surface swabbed for microbial analysis before fabrication into 2.54 cm strip steaks (n=5). Steaks assigned to slice shear force (SSF) were cooked to 71°C. A raw steak was used for microbial, proteolytic, and volatile analyses. Two-way interactions were observed for all spoilage organisms (P < 0.001). Aging for 42 and 56 d at−2°C produced lower microbial counts compared to individual aging durations at 4°C (P < 0.05). Loins aged for 14 d at 4°C had increased desmin and troponin-T degradation compared to aging for 14 at−2°C and 0°C (P < 0.05). Loins aged at 4°C produced more tender steaks compared to−2°C and 0°C (P = 0.001). Steaks aged for 42 and 56 d possessed the lowest SSF values (P < 0.05). Aging for 56 d at 4°C produced the greatest amount of total free amino acids (P < 0.001). Two-way interactions were observed for 7 compounds (alcohols, aldehydes, carboxylic acids, ketones, and sulfur-containing compounds; P < 0.05). Aging for 56 d at 4°C had the greatest ethanol concentration (P < 0.05). These data indicate aging at 4°C increases the rate of proteolysis and subsequent tenderness development and flavor precursor accumulation. However,extended aging at 4°C resulted in increased microbial counts. Many traits peaked at 42 d of aging.

The objectives of this study were to determine the influence of quality grade and internal temperature on the thermophysical properties of beef strip steaks. Beef strip loins (n=24) were collected from USDA Prime (PR), Low Choice(LC), and Standard (ST) carcasses. Strip loins were fabricated into 2.54 cm steaks at 21 d postmortem and randomly assigned to an internal temperature (4°C, 25°C, 55°C, 60°C, 71°C, 77°C). Steaks were subjected to various thermal and physical property measurements. No quality grade × internal temperature interaction was observed for diffusivity and conductivity (P > 0.05). Steaks tempered to 25°C had the greatest conductivity compared with all other internal temperature treatments (P = 0.021). A quality grade×internal temperature interaction was observed for center myosin and sarcoplasmic protein enthalpy values (P < 0.001). Raw (4°C and 25°C) ST steaks had lower enthalpy values compared with raw PR and LC steaks (P < 0.05). Raw steaks had greater surface myosin and both center and surface actin enthalpy values (P < 0.05). A quality grade × internal temperature was observed for surface and center viscoelasticity (P < 0.05). Raw steaks possessed less elastic behavior compared with cooked steaks, regardless of quality grade (P

The objective of this study was to determine the effect of various dry-aging methods on meat quality and palatability attributes of cull cow beef loins. Paired bone-in loins (m. longissimus lumborum) from 13 cull cow carcasses (Holstein, 42þ mo) were obtained at 5 d postmortem, divided into 4 equal sections, and randomly assigned into 4 aging methods (wet-aging [WA], conventional dry-aging [DA], dry-aging in water-permeable bag [DWA], and ultraviolet light dry-aging [UDA]). The beef sections were aged for 28 d at 2°C, 65% relative humidity, and 0.8 m/s airflow. Following aging, surface crusts and bones were removed, and loin samples were collected for the meat quality, microbiological, and sensory analyses. Results indicated that all dry-aged loins had greater moisture and trimming loss compared with WA (P < 0.05), while DWA had lower loss than DA and UDA (P < 0.05). No differences in shear force, cook loss, or both lipid and protein oxidation across all treatments were observed (P > 0.05). Among all treatments, DWA exhibited the least color stability indicated by rapid discoloration observed in the sample, while UDA had color attributes comparable with WA throughout the whole display. Microbial analysis indicated that UDA had lower microbial concentration on the surface than the other samples (P < 0.05). The consumer panel analysis found that all loins were acceptable, and the trained panel analysis indicated that DA loins decreased sourness and animal fat flavor (P < 0.05) and had a trend of decreasing oxidized flavor (P = 0.07). The results indicate that dry-aging can potentially be utilized as an effective natural process by nullifying some of well-known off-flavor attributes associated with cull cow beef while not compromising other meat quality attrib- utes or microbiological shelf life.

A consumer study was conducted to determine whether consumers scored beef palatability traits differently on paper versus digital ballots. Beef subprimals representing 4 treatments with inherent variation in eating quality were collected: USDA Select eye of round aged 7 d postmortem, USDA Select strip loin aged 7 d postmortem, USDA Choice tenderloin aged 21 d postmortem, and USDA Prime strip loin aged 21 d postmortem. Accessory muscles, external fat, and connective tissue were removed from subprimals. Muscles were fabricated into 2.5-cm steaks and further divided into 2 equal halves for consumer testing. Consumers (n = 360) evaluated 8 samples divided into 2 blocks representing the 2 ballot types. Within each ballot block, Select longissimus lumborum samples were always served in the first and fifth position, followed by the remaining 3 treatments served in a randomized order among the latter 3 positions. Consumers rated each steak sample for tenderness, juiciness, flavor liking, and overall liking from 0 to 100 on either a paper or a digital ballot and then rated the paired steak halves on the opposite ballot during the second block of sample testing. Ballot type influenced (P < 0.02) all traits, as consumers scored traits greater (P < 0.05) on paper compared with digital ballots, regardless of treatment. The magnitude of differences between ballot types was much smaller than the magnitude of differences between cut treatments, which also differed (P < 0.01). The smallest margin between ballot type was observed for tenderness (1.8 points); juiciness, flavor liking, and overall liking all differed by 3.4 points. Independent studies could and have utilized digital ballots without concern, as consumers sorted samples by treatment in the current study similarly, regardless of ballot type. However, researchers should consider ballot type for their sensory studies, especially if data will be added to a collective data set.

The objective of this study was to characterize descriptive sensory attributes and volatile compounds among ground beef (GB) and plant-based meat alternatives (PBMA). The Beyond Burger, Impossible Burger, a third brand of PBMA, regular GB, and lean GB were collected from local and national chain grocery stores. Patties were formed and cooked on an enamel-lined cast iron skillet to an internal temperature of 71 °C. A trained descriptive sensory panel evaluated patties for 17 flavor attributes and 4 texture attributes. Volatile compounds were extracted using solid phase microextraction and analyzed via gas chromatography-mass spectrometry. Distinct differences in sensory and volatile profiles were elucidated (p < 0.05). PBMA possessed decreased beef flavor intensity and increased umami, nutty, smokey-charcoal, and musty/earthy flavor compared to GB. Sensory differences corresponded with pyrazine, furan, ketone, alcohol, and aldehyde concentration differences between products. These data support the conclusion that ground beef and PBMA possess different flavor and texture characteristics. Furthermore, the flavor of PBMA varied among available retail brands.

The objective of this study was to evaluate the food safety efficacy of common antimicrobial interventions at and above required uptake levels for processing aids on the reduction of Shiga-toxin producing E. coli (STEC) and Salmonella spp. through spray and dip applications. Beef trim was inoculated with specific isolates of STEC or Salmonella strains. Trim was intervened with peracetic or lactic acid through spray or dip application. Meat rinses were serially diluted and plated following the drop dilution method; an enumerable range of 2–30 colonies was used to report results before log transformation. The combination of all treatments exhibits an average reduction rate of 0.16 LogCFU/g for STEC and Salmonella spp., suggesting that for every 1% increase in uptake there is an increase of 0.16 LogCFU/g of reduction rate. There is a statistical significance in the reduction rate of Shiga-toxin producing Escherichia coli in relation to the uptake percentage (p < 0.01). The addition of explanatory variables increases the R2 of the regression for STEC, where all the additional explanatory variables are statistically significant for reduction (p < 0.01). The addition of explanatory variables increases the R2 of the regression for Salmonella spp., but only trim type is statistically significant for reduction rate (p < 0.01). An increase in uptake percentages showed a significant increase in reduction rate of pathogens on beef trimmings.

The objective of this study was to determine the influence of dry-heat cookery method on beef flavor develop- ment in strip loin steaks from 2 USDA quality grades following sous vide preparation. Beef strip loins were selected from 2 USDA quality grades: upper 2/3 Choice (Modest00–Moderate100) and Select (Slight00–Slight100 marbling, n = 20/grade). Following 21 d of wet aging, strip loins were fabricated into 2.54-cm thick-steaks and randomly assigned to one of 4 dry- heat cookery methods: charbroiler grill (CHAR), clamshell grill (CLAM), convection oven (OVEN), and salamander broiler (SALA). Prior to untrained consumer panel and volatile compound analysis via gas chromatography-mass spectrometry, steaks were cooked under sous vide conditions for 1.5 h, then finished on the assigned cookery method. There were no cooking method ×quality grade interactions (P ≥ 0.076) for all consumer traits evaluated. Overall, SALA steaks received higher (P < 0.05) ratings by consumers than CLAM steaks for all palatability traits. OVEN steaks had greater scores (P < 0.05) than CLAM steaks for juiciness, tenderness, and overall liking but were similar to CLAM steaks (P > 0.05) for flavor. CHAR steaks were similar (P > 0.05) to CLAM steaks for flavor but were rated higher (P < 0.05) for tenderness, juiciness, and overall liking. Steaks cooked using the OVEN method produced a greater concentration of lipid-derived volatiles, such as alcohols, aldehydes, and carboxylic acids. In direct contrast, CHAR steaks produced a higher concentration of pyrazines and Strecker aldehydes, which are derived from the Maillard reaction. These data indicate that cookery method, and therefore heat transfer method, has a substantially stronger influence on consumer ratings and flavor development than USDA quality grade in this study when steaks are prepared using sous vide methods.

Beef volatile flavor compound (VFC) development at the center, mid, and surface layers of cooked steaks was evaluated through 18 cookery treatment combinations consisting of oven cooking temperature (OT; 177°C, 246°C, and 343°C) and final internal steak temperature (IT; 57°C, 63°C, 68°C, 74°C, 79°C, and 85°C). In total, 72 VFC were measured representing the Maillard reaction and lipid degradation. Five VFC were impacted by a three-way interaction of OT × IT × layer (P ≤ 0.030). Two VFC were impacted by a two-way interaction of OT × IT (P ≤ 0.010). Sixteen VFC were impacted by a two-way interaction of OT × layer (P ≤ 0.050). Sixteen VFC were impacted by a two-way interaction of IT × layer (P ≤ 0.050). Twenty VFC were impacted by the main effect of layer (P ≤ 0.010). Eight VFC were impacted by the main effect of IT (P ≤ 0.050). Maillard compounds were formed primarily at steak surfaces, with a general increase in content with greater final IT, and OT to a lesser extent. Lipid-derived compounds were diverse. Methyl esters and aldehydes had lower contents at steak surfaces and were primarily found within the inner portions of steaks. Conversely, certain alcohols and ketones were more prominent at steak surfaces. Development of compounds among layers was also consistently influenced by IT and OT. It may be concluded that flavor-contributing compounds vary among cooked beef steaks at different depths and cookery temperatures. As a result, OT and final IT may be utilized to mediate the final volatile compound composition.

To date, meat microbiology research has relied on culture-dependent methods. Amplicon sequencing technology provides a deeper look into the microbial community. This study set out to evaluate the bacterial community of fresh beef longissimus lumborum steaks exposed to retail packaging and display conditions. Four packaging treatments were assigned after fabrication 7 d postmortem: high-oxygen modified atmosphere packaging, overwrapped packages within a carbon monoxide tri-gas flushed motherbag, vacuum rollstock pouches, and traditional overwrap. After a 14-d dark storage, carbon monoxide motherbag overwrapped packages were removed from the motherbag, and packages were distributed to a retail lighting condition for 72 h of retail display: fluorescent, light emitting diode, or darkness. Aerobic plate count and psychrotrophic bacteria were enumerated, in addition to 16S ribosomal RNA sequencing of DNA for microbial profile investigation. Sampling occurred at fabrication (7 d), end of dark storage (20 d), and end of retail display (23 d). The V3–V4 regions of the 16S bacterial ribosomal RNA gene were sequenced using the Illumina MiSeq platform (Illumina, San Diego, CA). Counts for aerobic plate count bacteria differed by packaging (P = 0.039) but not lighting (P > 0.05). Firmicutes and Proteobacteria were the dominate phyla identified but were not affected by packaging or lighting (P > 0.05). Traditional overwrapped packages displayed in darkness and fluorescence had a higher abundance of Carnobacterium compared with those displayed under light emitting diode (P = 0.05). Dark-stored samples had more Pseudomonas compared with fluorescent display, regardless of packaging type (P = 0.03). While packaging and lighting conditions had a minimal impact on the community composition, these data positively contribute to a baseline establishing bacterial community profiles of fresh beef steaks subjected to retail display. This foundation suggests that further work is needed to understand whether shifts are more likely to occur during extended shelf life or in other retail beef display conditions.

This study evaluated associations of heat shock proteins (HSP) and an oxidative stress protein, protein deglycase (DJ1), with beef quality and tenderness. Samples from the longissimus thoracis (N = 99) were collected pre-rigor (day 0) and after 14-d aging. Warner-Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), and a trained sensory panel were used to determine meat quality. Protein abundance of DJ1 and 2 HSP—HSPβ1 and HSPA—were assessed. Regression analyses demonstrated that DJ1 abundance after 14 d of aging is a predictor of WBSF (P < 0.001), MFI (P = 0.02), and sensory panel tenderness (P < 0.001). Abundance of HSPβ1 after 14 d of aging is also a predictor of MFI (P = 0.03). Additionally, abundance of both HSPβ1 and DJ1 pre-rigor are predictors of juiciness (P < 0.05). Abundance of HSPβ1 pre-rigor was correlated with WBSF (R = 0.67), sensory panel tenderness (R = −0.44), juiciness (R = −0.30), and umami (R = −0.20). Abundance of DJ1 pre-rigor was also correlated with WBSF (R = 0.72), sensory panel tenderness (R = −0.44), juiciness (R = − 0.24), and umami (R = −0.31). After 14-d aging, HSP β 1 abundance was cor- related with WBSF (R = 0.66), sensory panel tenderness (R = −0.34), juiciness (R = −0.34), umami (R = −0.33), and brown/ roasted (R = −0.30). Abundance of DJ1 after 14-d aging was also correlated with WBSF (R = 0.68), sensory panel tenderness (R = −0.41), juiciness (R = −0.21), and umami (R = −0.28). These results demonstrate that abundance of HSPβ1 and DJ1 both pre-rigor and after 14 d of aging are correlated with meat tenderness and end-product quality as assessed by a trained sensory panel. Regression analyses further reveal that abundance of DJ1 and HSPβ1 after 14 d of aging is causative in development of beef tenderness and juiciness, respectively. Taken together, these results suggest that abundance of DJ1 is a predictor of tenderness, whereas abundance of HSPβ1 is related to meat quality but cannot be used to predict tenderness.

The objective of this study was to determine the influence of dry-heat cookery on beef flavor development of multiple beef muscles. Beef strip loins, top sirloin butts, paired tenderloins, paired shoulder clods, and chuck rolls were collected from USDA Low Choice carcasses (Small00–Small100 marbling; N = 20). Subprimals were wet aged in the absence of light for 21 d at 0°C to 4°C. Subprimals were fabricated into 2.54-cm-thick steaks representative of the following muscles: Gluteus medius, Infraspinatus, Longissimus lumborum, Psoas major, Serratus ventralis, and Triceps brachii and randomly assigned to one of 4 dry-heat cookery methods: charbroiler grill (CHAR), clamshell grill (CLAM), convection oven (OVEN), and salamander broiler (SALA). Steaks were cooked to a medium degree of doneness (71°C) on the randomly assigned cooking method. Untrained consumer panelists (N = 300) evaluated each sample for flavor, tenderness, juiciness, and overall liking. No interactions were observed between cooking method and muscle (P ≥ 0.344) for any palatability traits evaluated. Consumers preferred CHAR steaks (P < 0.05) over CLAM steaks for flavor, tenderness, juiciness, and overall liking. Additionally, CLAM steaks were rated lower (P < 0.05) than all other methods for tenderness and juiciness. OVEN and SALA steaks were rated higher (P < 0.05) than CLAM steaks by consumers for tenderness and juiciness but were similar (P > 0.05) to CLAM steaks for overall liking. CHAR steaks produced a greater concentration of Maillard compounds compared with the other cooking methods. Steaks cooked using OVEN and SALA (P < 0.05) produced more lipid oxidation products. Additionally, CHAR steaks produced the greatest (P < 0.05) total volatile production compared with all other treatments, which may be a result of the combination of Maillard reaction products and the lipid degradation products.

This research analyzed how maternal plane of nutrition during mid-gestation impacts growth, blood metabolites, expression of microRNA and messenger RNA in skeletal muscle, feedlot performance, and carcass characteristics of progeny. Thirty-two cows were bred to the same Angus sire and fed to either maintain a body condition score (BCS) of 5.0 to 5.5 (maintenance [MAIN]; n = 15) or to lose 1 BCS (restriction [REST]; n = 17) over an 84-d period of mid-gestation. Following the second trimester, all cows were co-mingled and fed at maintenance for the remainder of gestation. Following the 84-d treatment period, REST cows had a lower (P < 0.01) BCS than MAIN cows. At the end of the third trimester, there was no difference (P = 0.78) in BCS between the treatment groups. There was no difference (P > 0.10) between offspring in birthweight, weaning weight, average daily gain, feed efficiency, dry matter intake, carcass yield, steak quality, or in circulating levels of glucose, cortisol, insulin, or insulin-like growth factor-1. REST offspring expressed more (P < 0.05) miR-133a, miR-133b, miR-181d, miR-214, miR-424 and miR-486 at weaning than MAIN offspring. At harvest, REST offspring expressed more (P < 0.05) miR-133a and less (P < 0.01) miR-486 than MAIN offspring. REST steaks were perceived as more tender (P = 0.05) by a trained sensory panel. These results indicate that maternal nutrient restriction during mid-gestation resulting in a loss of 1 BCS has an effect on microRNA expression in the skeletal muscle but does not alter postnatal growth potential, carcass quality, or end product quality of the offspring. This suggests that moderate restriction in maternal nutrition during the second trimester, which results in a drop in BCS that can be recovered during the third trimester, should not cause alarm for producers when considering future offspring performance.

The objective of this study was to investigate differences in smoked beef brisket palatability from 3 USDA quality grades (USDA Prime, average [middle 1/3] Choice, and Select). Briskets (n = 54; 18 per quality grade) were seasoned with a blend of 1:1 coarse salt/black pepper, and then cooked in a smoker to a final internal temperature of 93°C for approximately 6 to 7 h. For sensory analysis, briskets were separated into point (pectoralis superficialis) and flat (pectoralis profundus) portions and then sliced perpendicular to the muscle fibers. Consumer panelists (N = 360) evaluated palatability traits, acceptability of each trait, and willingness to pay (WTP). An interaction between quality grade and muscle was observed (P ≤ 0.03) for all palatability traits, proportion of acceptable samples, and WTP. Consumers could not distinguish among quality grades of the point portions for tenderness, juiciness, flavor liking, and overall liking (P > 0.05). Point samples, regardless of quality grade, were scored greater (P < 0.05) than Prime flat samples for all palatability traits. Choice and Select flat samples were scored lesser (P < 0.05) than all other treatment combinations for tenderness, flavor liking, and overall liking. In alignment with palatability traits, consumers’ WTP was greatest for point portions, regardless of quality grade (P < 0.05), followed by Prime flat portions. Choice and Select flat portions had the lowest WTP (P < 0.05). Consumer acceptability of cooked beef brisket generally followed similar trends as palatability scores. Quality grade had no effect on the eating quality of the point portions of smoked briskets, and point portions received superior palatability scores to flat portions. Prime flat portions had greater eating quality compared to that of Choice and Select flat portions, and consumers had greater WTP for what they perceived as superior eating quality.

The objective of this study was to characterize and compare the dry-aging flavor precursors and their liberation mechanisms in beef aged with different methods. Thirteen paired loins were collected at 5 days postmortem, divided into four sections, and randomly assigned into four aging methods (wet-aging (WA), conventional dry-aging (DA), dry-aging in a water-permeable bag (DWA), and UV-light dry-aging (UDA)). All sections were aged for 28 days at 2 °C, 65% RH, and a 0.8 m/s airflow before trimming and sample collection for chemical, metabolomics, and microbiome analyses. Higher concentrations of free amino acids and reducing sugars were observed in all dry-aging samples (p < 0.05). Similarly, metabolomics revealed greater short-chain peptides in the dry-aged beef (p < 0.05). The DWA samples had an increase in polyunsaturated free fatty acids (C18:2trans, C18:3n3, C20:2, and C20:5; p < 0.05) along with higher volatile compound concentrations compared to other aging methods (aldehyde, nonanal, octanal, octanol, and carbon disulfide; p < 0.05). Microbiome profiling identified a clear separation in beta diversity between dry and wet aging methods. The Pseudomonas spp. are the most prominent bacterial species in dry-aged meat, potentially contributing to the greater accumulation of flavor precursor concentrations in addition to the dehydration process during the dry-aging. Minor microbial species involvement, such as Bacillus spp., could potentially liberate unique and potent flavor precursors.

Volatile compounds, carbonyls, non-heme iron, and thiobarbituric acid reactive substances (TBARS) were measured in both raw and cooked beef samples to determine the effects of muscle and packaging type on beef flavor development. All paired strip loins and top sirloin butts were packaged under vacuum and aged for 14 d postmortem. After initial aging, all subprimals were fabricated to produce M. gluteus medius (GM) or M. longissimus lumborum (LL) steaks. At 14 d postmortem, steaks were randomly assigned to 1 of 5 package types: high-oxygen modified atmosphere lidded trays (80% O2/20% CO2 [“HIOX”]), carbon monoxide modified atmosphere lidded trays (0.4% CO/30% CO2/69.6% N2 [“CO”]), rollstock (forming and non-forming films [“ROLL”]), vacuum packaging without retail display (“VAC”), and traditional overwrap (“OW”) remained under vacuum prior to retail display. Steaks were stored in darkness an additional 7 d prior to display. At 21 d postmortem, HIOX, OW, CO, and ROLL packages were displayed for 48 h under continuous fluorescent lighting, while VAC steaks remained in dark storage. Packaging and muscle type impacted (P < 0.05) quantities of multiple volatile flavor compounds, including alcohols, n-aldehydes, esters, furans, hydrocarbons, sulfur-containing compounds,and ketones in both raw and cooked samples. Volatile compounds related to lipid oxidation were more (P < 0.05) prominent in HIOX packaging. Package type (P < 0.05) and muscle (P < 0.05) had an impact on raw-steak TBARS, although package type did not influence (P > 0.05) cooked-steak TBARS. The GM possessed greater (P < 0.05) TBARS values than the LL in both raw and cooked samples. Package type had no effect (P > 0.05) on carbonyl and non-heme iron content although these analyses differed among muscles (P < 0.05), with the GM being greater (P < 0.05) than the LL. These results indicate that the development of lipid oxidation that occurs during storage and display was muscle and packaging specific. Therefore, to maintain flavor, quality packaging systems should be selected on a muscle-specific basis.

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 > 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.

Varying aging times and methods were evaluated for their effect on flavor, tenderness, and related changes involatile compounds and flavor precursors. Strip loin sections from USDA Choice beef carcasses (n = 38) were randomly assigned to treatments: (1) 3 d wet-aged, (2) 14 d wet-aged, (3) 28 d wet-aged, (4) 35 d wet-aged, (5) 49 d wet-aged, (6) 63 d wet-aged, (7) 21 d dry-aged, and (8) 14 d wet-aged followed by 21 d dry-aged. Samples were analyzed for trained sensory attributes, shear force, volatile compounds, and flavor precursors (fatty acids, free amino acids, and sugars). Discriminant function analysis was used to identify sensory attributes contributing the greatest to treatment differences. Flavor notes were not differentiated in beef aged up to 35 d, regardless of aging method. A shift in flavor occurred between 35 d and 49 d of wet-aging time that was characterized by more intense sour and musty/earthy notes. Both shear force assessment and trained panelists agreed that tenderness was not affected (P > 0.05) by additional aging beyond 28 d. Volatile compound production and liberation of amino acids and sugars increased (P < 0.01) during the progression of aging time, with no change (P > 0.05) in fatty acid composition, which may be a result of metabolic processes like microbial metabolism. Chemical properties shared strong positive relationships (r > 0.50, P < 0.001) with sour, musty/earthy, and overall tenderness. These results substantiate the deteriorative effect of extended aging times of 49 d or greater on flavor of beef strip loins without tenderness improvement.

The objectives of this study were to determine the influence of package and muscle type on postmortem proteolysis and subsequent release of flavor-contributing free amino acids during storage. Beef strip loins and top sirloin butts (n = 20/subprimal) from USDA Low Choice carcasses were fabricated into 2.54-cm steaks (M. longissimus lumborum and M. gluteus medius) at 7 d postmortem. Steaks were randomly assigned to packaging treatments (carbon monoxide mother-bag [CO], high-oxygen modified atmosphere packaging [HIOX], polyvinyl overwrap [OW], or rollstock [ROLL]) and aged for an additional 14 d in dark storage. Steaks intended for OW were initially vacuum packaged during dark storage,then overwrapped just prior to display. Steaks were placed in coffin-style retail cases for 48 h under fluorescent lighting to simulate retail display. HIOX steaks exhibited the highest Warner-Bratzler shear force values (P < 0.05); the lowest desmin degradation rate (P < 0.05); the highest ratings for fishy, bitter, sour, and oxidized flavors; and the lowest overall tenderness scores (P < 0.05) and, in general, produced the lowest amount of free amino acids (P < 0.05) compared with all other treatments. Contrastingly, ROLL packaging produced the highest ratings for beef flavor identity, brown/roasted, bloody/serumy, and umami flavors (P < 0.05). Additionally, ROLL packaging exhibited (P < 0.05) greater desmin degradation in comparison with HIOX steaks. These data indicate that the optimum package for storage and aging is an anaerobic environment to maintain optimum flavor, tenderness, and postmortem proteolysis.

The study objective was to evaluate the effects of extended postmortem wet aging of Australian beef, cattle diet, and their interaction on objective and subjective measures of beef flavor of the longissimus lumborum. Beef strip loins were collected from grass- and grain-fed cattle (n = 50 total) at a commercial abattoir near Brisbane, Australia. Beef longissimus lumborum were portioned and assigned randomly to one of 3 postmortem aging periods (45, 70, or 135 d). As each section reached its respective postmortem aging designation, that section was fabricated into 2.5-cm steaks, individually vacuum packaged, and frozen (−21°C). Trained panelists evaluated cooked steaks for numerous flavor attributes, tenderness, and juiciness; volatile compounds were also evaluated. Sensory scores differed (P < 0.05) due to diet, whereby grain-fed samples were rated more intense (P < 0.05) for beef flavor identity, fat-like, liver-like, and sweet but grass-fed samples were more intense (P < 0.05) for green-hay and bitter. Juiciness, tenderness, and 4 flavor attributes (bloody/serumy, metallic, umami, and rancid) were similar (P > 0.05) between diets. Extending postmortem aging from 45 to 135 d resulted in decreased beef and umami flavors (P < 0.05), along with concurrent increased detection of off-flavors, such as liver-like, rancid, bitter, and sour (P < 0.05). Volatile flavor compounds were more influenced by postmortem aging than diet. Increased postmortem aging time increased concentration for both lipid oxidation and Maillard-reaction–derived volatiles, resulting in the concentration of negative flavor volatile compounds rather than the absence of positive flavor compounds. Based on these results, differences existed in the flavor profile of longissimus lumborum from grass- and grain-fed beef, regardless of postmortem aging. However, aging beef strip loins 135 d is not recommended based on reduced beef flavor and increased off-flavor detection compared to samples aged 45 or 70 d postmortem.

Our objective was to investigate the effects of extended aging on the flavor characteristics of Australian grass- and grain-fed beef longissimus thoracis. Ribeye rolls from Australian grass- and grain-fed beef carcasses were collected, randomly assigned to one of 4 postmortem aging days (35, 45, 55, and 65), vacuum packaged, and shipped under refrigeration (0°C–2°C) to Texas Tech University (Lubbock, TX). Aged longissimus thoracis were fabricated on their respective aging day into 2.54-cm steaks, vacuum packaged individually, and frozen (−24°C) until further analyses. According to trained flavor panelists, beef flavor identity, fat-like, metallic, umami, bitter, and sweet flavors were not influenced by diet or postmortem aging (P > 0.05). Diet influenced (P < 0.05) liver-like, rancid, grassy, and sour flavors, as well as juiciness. For all flavors except liver-like, grass-fed samples had stronger flavors than grain-fed samples. Postmortem aging influenced (P < 0.05) bloody/serumy, liver-like, rancid, and grassy flavors, along with tenderness and juiciness. Flavor detection typically became stronger for those flavors as postmortem aging increased; however, bloody/serumy, juiciness, and tenderness generally did not follow a linear trend as postmortem aging increased. Content of acetic acid and hexanal were each greater (P < 0.05) in grain-fed beef. The majority of lipid oxidation compounds were most prominent (P < 0.05) in samples aged 45 and 55 d, while content in 35 and 65 d were lower and did not differ (P > 0.05). Aging also influenced content of acetic acid and ethanol (P ≤ 0.04), which increased with aging duration. For 1-octen-3-ol, grain-fed samples aged 65 d had the greatest (P < 0.05) content compared with all other diet and aging combinations. Results indicate that aging up to 65 d had no impact on beef flavor identity and umami, but it led to stronger generation of certain off-flavors such as rancid, grassy, and liver-like.

This study aimed to evaluate the sensory and physical characteristics of zingibain-injected meat combined with sous vide cooking. M. biceps femoris (BF; n = 12) acquired from 6–7 year old Angus cows were cooked using the sous vide method at 65 °C, for 8 h or 12 h, either with ginger powder (GP) injected in a 2 g/L solution in water (treatment) or un-injected (control). The sensory attributes included flavour, juiciness, tenderness, and physicochemical characteristics were Warner-Bratzler shear (WBSF), hardness, total water content (TWC), cooking loss (CL) and collagen content. A significant improvement in tenderness with injection treatment and cooking time was observed, as evaluated through trained sensory panellists, and reduced WBSF and hardness (p < 0.05 for all). The flavour of the meat was not affected by injection treatment or cooking time (p > 0.05), but juiciness and TWC were reduced with longer cooking times (p < 0.01 for both). Soluble collagen increased with injection treatment and cooking time (both p < 0.05). Moderate to high correlations were found between sensory and physical measurements for tenderness and juiciness. The longer cooking time (12 h) with GP injection treatment caused over tenderization of the meat. The soft texture associated with over-tenderization may be suitable for some specialised consumer markets, for instance, the elderly population with chewing difficulties. Improving the eating quality of low-quality meat from old animals through sous vide cooking and the use of ginger proteases may increase the acceptability of lower value beef, potentially enhancing the commercial value of carcasses typically produced in the beef industry.

The objective of this research was to investigate the influence of maternal prepartum dietary carbohydrate source on growth performance, carcass characteristics, and meat quality of offspring. Angus-based cows were assigned to either a concentrate-based diet or forage-based diet during mid- and late-gestation. A subset of calves was selected for evaluation of progeny performance. Dry matter intake (DMI), body weight (BW), average daily gain (ADG), gain to feed (G:F), and ultrasound measurements (muscle depth, back fat thickness, and intramuscular fat) were assessed during the feeding period. Carcass measurements were recorded, and striploins were collected for Warner-Bratzler shear force (WBSF), trained sensory panel, crude fat determination and fatty acid profile. Maternal dietary treatment did not influence (p > 0.05) offspring BW, DMI, ultrasound measurements, percent moisture, crude fat, WBSF, or consumer sensory responses. The forage treatment tended to have decreased (p = 0.06) 12th rib backfat compared to the concentrate treatment and tended to have lower (p = 0.08) yield grades. The concentrate treatment had increased (p < 0.05) a* and b* values compared to the forage treatment. These data suggest variation in maternal diets applied in this study during mid- and late-gestation has limited influence on progeny performance.

Consumer sensory analysis (n = 288) was conducted, along with cooking loss, slice shear force (SSF), pressed juice percentage (PJP), and volatile compound analyses, to evaluate the effects of different dry heat cooking methods. Specifically, an electric clamshell grill (CLAM), flat top gas grill (FLAT), charbroiler gas grill (CHAR), and salamander gas broiler (SAL) were used to cook beef strip loin steaks from 4 USDA quality grades [Prime, Top (upper 2/3) Choice, Low (lower 1/3) Choice, and Select)] to determine the palatability. Cooking method and quality grade influenced (P < 0.01) consumer tenderness, juiciness, flavor liking, and overall liking. Steaks cooked on CHAR had greater (P < 0.05) flavor liking and subsequently greater overall liking than any other cooking method. Steaks cooked on FLAT were scored lower for tenderness and juiciness than any other cooking method (P < 0.05), whereas steaks cooked on CLAM had lower (P < 0.05) flavor liking scores than any other cooking method, excluding FLAT. Overall acceptance was greater (P < 0.05) for steaks cooked on CHAR compared to all other cooking methods, regardless of quality grade. Prime samples had greater scores than Low Choice and Select for tenderness, juiciness, flavor liking, and overall liking (P < 0.05), but Prime did not differ from Top Choice for all traits. No main effects or interactions influenced (P > 0.05) SSF or PJP. Both cooking method and quality grade impacted (P < 0.05) the headspace concentration of some volatile compounds in the alcohol, n-aldehyde, Strecker aldehyde, and furan groups. Cooking method also affected all pyrazines, and quality grade had an effect on 1 ketone (P < 0.05). These results indicate cooking method had a significant impact on consumer palatability ratings and objective measures of beef flavor, and those results were consistent across a range of quality grades.

The objective of this study was to determine the impact of enhancement, degree of doneness (DOD), and USDA quality grade on beef volatile flavor compounds from cooked strip loin steaks. This study also aimed to evaluate relationships between volatile compounds and consumer sensory responses. Beef strip loins (n = 72; 24/grade) of 3 quality grades (USDA Prime, Low Choice, and Low Select) were enhanced (8% of green weight with brine containing 0.35% salt and 0.4% sodium phosphate) or not enhanced, and cooked to 3 DOD (Rare: 60°C; Medium: 71°C; Very Well Done: 83°C) before volatile analysis. Volatile compounds were evaluated through a split-plot design where enhancement level and quality grade were used as the whole plot factors and DOD served as the subplot factor. Principal component analysis (PCA) was utilized to explore relationships between volatile compounds, consumer response, and treatments. The majority of compounds (n = 32) were impacted (P < 0.05) by the interaction between DOD × enhancement × quality grade. Four compounds- methanethiol, dimethyl-disulfide, methyl-benzene, and acetic acid were affected (P < 0.05) by enhancement × DOD. Two compounds- dimethyl sulfone and d-limonene, were impacted (P < 0.05) by quality grade × enhancement. Phenylacetaldehyde and hexanoic acid, methyl ester was affected (P < 0.05) by the interaction of USDA quality grade × DOD. The DOD main effect was only implicated in Maillard products (P < 0.05), including 2-methylbutanal, a Strecker aldehyde, and 2 pyrazines (methyl-pyrazine and trimethylpyrazine). Nonanal was the only compound impacted (P < 0.05) by a quality grade effect. No enhancement main effects were observed for any compounds (P > 0.05). In agreement, PCA indicated volatile compound production was primarily driven by degree of doneness and quality grade. There was no strong link between enhancement and beef volatile flavor compound development, despite the dramatically improved flavor liking scores from consumers.

Sensory evaluation was conducted to investigate the impact of packaging system and muscle type on beef flavor. Beef M. Longissimus lumborum (LL) and M. Gluteus medius (GM) steaks were produced from vacuum packaged subprimals at 14 d postmortem. Steaks were placed in various packaging types and held for 7 d prior to 48 h of retail display under continuous fluorescent lighting. Packaging types included: high-oxygen modified atmosphere lidded trays (80% O2/20% CO2, HIOX), carbon monoxide modified atmosphere lidded trays (0.4% CO/30% CO2/69.6%N2, CO), rollstock (forming/non-forming films, ROLL), vacuum packaging (stored in darkness, VAC), and traditional overwrap (foam trays wrapped with polyvinyl chloride film immediately before display, OW). Steaks were evaluated after cooking by consumer panelists and a trained descriptive attribute panel. For consumer evaluation, a muscle × package type interaction (P = 0.040) occurred for juiciness. Overall liking, tenderness, and liking of flavor were influenced (P ≤ 0.003) by package type. Overall liking, liking of flavor, and tenderness of HIOX was lower (P < 0.05) than all other package types. Additionally, package type impacted (P ≤ 0.030) overall, flavor, and tenderness acceptability. Overall and flavor acceptability was the lowest (P < 0.05) for the HIOX treatment. From trained panel attribute evaluation, muscle × package type interactions were detected (P ≤ 0.021) for brown/roasted, bloody/serumy, and juiciness. Juiciness was the least (P < 0.05) desirable for GM HIOX compared to all other muscle and package type combinations. Steaks from HIOX packages had the highest (P < 0.05) ratings for oxidized and cardboardy, and were rated lowest (P < 0.05) in beef flavor ID and umami compared with all other package types. The LL had greater (P < 0.05) beef flavor ID, fat-like, umami, sweet, and overall tenderness ratings than the GM. The GM was more (P < 0.05) liver-like and oxidized compared with the LL. These data indicate a high oxygen packaging environment has the potential to accentuate negative descriptive sensory attributes and lower consumer sensory scores, while diminishing palatability in both muscles.

Proximate composition, Warner-Bratzler shear force (WBSF), consumer sensory traits, fatty acid composition, and volatile flavor compounds were assessed on steaks from USDA Select strip loins (n = 40; 8/treatment) representing grass-fed beef sourced from New Zealand (NZ) with marbling consistent with USDA Select along with strip loins from four feeding treatments designed to evaluate the effects of early exposure to grain-based diets for 0 d (0D), 40 d (40D), 80 d (80D), or 120 d (120D) prior to pasture-finishing on meat quality and composition. Percent fat, moisture, and protein and WBSF did not differ (P > 0.05), but percent ash was decreased in 120D samples compared to those from NZ, 0D, and 40D (P < 0.05). Consumer scores for all traits differed among samples from the treatments (P < 0.05), with steaks from NZ receiving greater scores for flavor liking than those from 0D, 40D, and 80D (P < 0.05). Consumers also rated NZ and 120D samples greatest for overall liking (P < 0.05). Saturated fatty acids were decreased, and monounsaturated fatty acids were increased in NZ samples compared to samples from all other treatments (P < 0.05), and conjugated linoleic acid was least in samples from NZ (P < 0.05). The ratio of omega-6 to omega-3 fatty acids was greater in 80D and 120D samples than those from all other treatments (P < 0.05). Non-enzymatic browning-derived ketones and 2-pentylfuran were increased in samples from NZ compared to those from all other treatments (P < 0.05), and differences among treatments in lipid-derived compounds were primarily of alcohols and aldehydes. Early exposure to grain-based diets for 120 d prior to pasture-finishing produces beef that is comparable to grass-fed beef from New Zealand in palatability but differs in chemical composition.

The objective of this study was to evaluate the roles that cooking rate and relative humidity has on the sensory development of beef strip steaks. Thirty USDA Choice beef strip loins were collected from a commercial packing facility. Each strip loin was cut into steaks and randomly assigned to 1 of 6 cooking methods utilizing 2 oven temperatures (80°C and 204°C) and 3 levels of relative humidity [zero (ZH), mid (MH), and high (HH)]. Cooked steaks were used to evaluate internal and external color, Warner-Bratzler and slice shear force, total collagen content, protein denaturation, and trained sensory ratings. Relative humidity greatly reduced cooking rate, especially at 80°C. Steaks cooked at 80°C-ZH had the greatest (P < 0.01) cook loss of all treatments, and cook loss was not affected (P > 0.05). Steaks cooked at 80°C-ZH appeared the most (P < 0.01) well-done and had the darkest (P > 0.01) surface color. Total collagen was greatest (P < 0.01) in steaks cooked with ZH, regardless of oven temperature. Myosin denaturation was not affected (P > 0.05) by treatment. Increased (P = 0.02) sarcoplasmic protein denaturation was observed with ZH and MH, while increased (P = 0.02) actin denaturation was observed only with ZH. Oven temperature did not influence (P > 0.05) protein denaturation. Trained panelists rated steaks the most tender (P < 0.01) when cooked at 80°C and with ZH and MH. Humidity did not affect (P > 0.05) juiciness at 204°C; however, MH and HH produced a juicier (P < 0.01) steak when cooked at 80°C. Humidity hindered (P < 0.01) the development of beefy/brothy and brown/grilled flavors but increased (P = 0.01) metallic/bloody intensity. Lower oven temperatures and moderate levels of humidity could be utilized to maximize tenderness, while minimally affecting flavor development.

Descriptive trained sensory attributes, fatty acids, and volatile compounds were determined to characterize the effects of dry-aging on ground beef. Beef shoulder clods were ground to include 100% fresh beef, 100% dry-aged beef, and a 50% fresh and 50% dry-aged ground beef blend. Samples comprised of 100% dry-aged beef were rated greatest (P < 0.001) for browned/grilled, earthy/mushroom, and nutty/roasted-nut flavors; however, panelists also detected greater (P ≤ 0.011) incidences of sour/acidic and bitter flavors. The addition of dry-aged beef increased (P < 0.001) hardness and reduced (P < 0.001) tenderness. Dry-aging also caused a shift in saturated fatty acids, where shorter chain saturated fatty acids (≤ 16:0) were reduced (P ≤ 0.034) compared to stearic acid (18:0). Meanwhile, increases of trans-octadecenoic acid (18:1 trans) and decreases of cis monounsaturated fatty acids were present in dry-aged beef. Concentrations of 18:2 conjugated linoleic isomers were greatest (P < 0.001) in fresh beef and decreased with the incorporation of dry-aged beef. Several lipid-derived volatile compounds were greater (P < 0.05) in dry-aged beef compared with fresh beef, implying a greater degree of lipid degradation among dry-aged beef. Increases (P ≤ 0.031) were determined for 3- and 2-methyl butanal with the addition of dry-aged beef. Intermediates of the Maillard reaction, 2,3-butanedione and acetoin, were determined to be greatest (P ≤ 0.046) from dry-aged beef. Alterations of fatty acids and volatile compounds with dry-aging were determined to be related with intensity of individual flavor attributes. Overall, it may be concluded that inclusion of dry-aged beef impacts flavor profile through altered fatty acid profiles and flavor related compounds. These results support the idea that dry-aging may be utilized to impart an altered ground beef flavor experience.

The effects of experimental finishing diets and enhancement were tested to determine if they could improve Honduran beef palatability. Fifteen enhanced (ENH) and non-enhanced (NE) paired loins from 7 different finishing diets (n = 210 loins) were fed to Honduran consumers (n = 288). Diets consisted of a grass-finished control (CON) or diets with the inclusion of distiller’s dry grain (DDG), palm kernel meal (PKM), PKM replication (PKMR), sorghum (SORG), soybean meal and corn (SBMC), or sugarcane (SC). An interaction (P < 0.01) occurred between diet and enhancement to influence scores for all palatability traits, willingness to pay (WTP), and acceptability of traits. Consumers found enhanced samples were more tender (P < 0.05) than NE counterparts, excluding ENH- and NE-CON (P > 0.05). Without enhancement, CON was rated more tender (P < 0.05) than all other treatments, except PKMR. All ENH samples were juicier (P < 0.05) and had a flavor that was liked more (P < 0.05) than NE counterparts. Diet alone resulted in similar (P > 0.05) juiciness scores between CON, DDG, PKM, and PKMR; however, CON was rated juicier (P < 0.05) than all other treatments. Among NE samples, flavor liking scores were not different (P > 0.05) between CON, DDG, PKM, PKMR, and SBMC, and CON was liked more (P < 0.05) than SORG and SC. All enhanced steaks, except CON, had greater overall liking scores and WTP values (P < 0.05) than NE counterparts. Diet alone resulted in similar (P > 0.05) overall liking and WTP values between CON, DDG, PKM, PKMR, and SBMC, while SORG and SC were liked less overall (P < 0.05) than CON, which reduced (P < 0.05) WTP values. Experimental diets in conjunction with enhancement were able to improve the consumers’ perception of palatability traits, acceptability, and WTP.

Consumer sensory analysis was performed to evaluate the effects of three marbling categories [LOW, Intermediate (MED), and HIGH] and 2 postmortem aging categories (21 d and 42 d) on the palatability of lamb loin chops as determined by U.S. consumers and to determine the relationship between marbling, flank streaking, intramuscular fat percentage (IMF), and palatability traits. Marbling and aging did not interact to affect any of the scores for palatability attributes, their acceptances, or the frequency of their overall eating quality classifications (P < 0.05). Consumers rated HIGH treatments (P < 0.05) as more tender, juicier, and with greater flavor liking and overall liking than MED or LOW, which were similar for all traits (P > 0.05). Aging also influenced (P < 0.05) all traits, as consumers scored 21 d samples greater for all palatability traits than their 42 d counterparts. A greater (P < 0.05) percentage of consumers categorized 42 d samples as ‘unsatisfactory’ and fewer as ‘better than everyday’ or ‘premium quality’ than 21 d samples. A larger proportion of consumers categorized HIGH samples as ‘premium quality’ than MED or LOW and fewer called HIGH ‘good everyday quality’ compared to MED (P < 0.05). Flank streaking, marbling score, and IMF were all influenced (P < 0.01) by marbling category in a linear fashion. Increasing marbling score, more so than flank streaking, was positively linked to increasing eating quality scores. Also, tenderness, juiciness and flavor liking are major drivers for consumer sensory scores for overall liking, with flavor liking having the strongest relationship to overall liking of lamb. Overall, consumers preferred HIGH marbling over LOW and MED marbling loin chops, but had difficulty distinguishing between LOW and MED. Furthermore, extending postmortem aging of lamb loin from 21 to 42 d reduced scores for eating quality traits.