Evaluation of marbling and enhancement's abilities to compensate for reduced beef palatability at elevated degrees of doneness

USA millennial and non-millennial beef consumers perception of beef, pork, and chicken

Millennials have been shown to have distinctly different behaviors; however, factors affecting their liking of beef, pork and chicken has not been fully elucidated. As millennials are current and future animal protein consumers, the question of if they have different drivers of liking for beef, pork, and chicken has not been answered. Top loin steaks cooked to 58.3 or 80 °C; and pork loin chops and chicken breasts cooked to 62.7 or 80 °C were cooked on a flat grill. Beef bottom round roasts cooked to 58.3 or 80°; and pork inside ham roasts and chicken thighs were cooked to 62.7 or 80 °C in a Crock-pot®. A descriptive flavor and texture attribute panel and a consumer central location test in four cities were used to evaluated flavor and texture attributes. Consumers were either millennials or non-millennials, and light or heavy beef-eaters. Meat descriptive flavor and texture attributes differed by cooking method, cut, and internal temperature (P < 0.05). Consumers preferred grilled meat more than meat cooked in the Crock-pot® (P > 0.05). Consumers rated grill flavor, juiciness, and tenderness (P ≥ 0.05) higher in grilled meat. Light beef-eaters, those who ate beef 2 to 4 times per month, rated overall, flavor, and species flavor lower (P < 0.05) than heavy beef-eaters, but consumers liked beef regardless of generational segment or their consumption of beef; however, millennials rated overall, overall flavor, and tenderness liking slightly lower than non-millennials. These results indicate that millennials have similar drivers of liking as non-millennials across beef, pork, and chicken protein sources.

A current review of U.S. beef flavor II: Managing beef flavor

Beef flavor continues to be one of the largest drivers of beef demand and a differentiation point of beef from other competing proteins. Tenderness has long been identified as the most important palatability trait for consumer satisfaction. However, as technological advancements and industry practices evolve and improve in response to tenderness management, flavor has emerged as a key driver of consumer satisfaction. In response, the beef industry has recently invested in research focused on beef flavor development, measurement, and management to better understand the factors impacting flavor and help beef maintain this advantage. The current review paper is the second of two such papers focused on summarizing the present knowledge and identifying knowledge gaps. While the other review focuses on current practices related to beef flavor measurement, this review will cover research findings related to beef flavor management. Numerous production and product management factors influence beef flavor. Pre-harvest factors including marbling level, animal genetics/cattle type, diet, and animal age, can influence beef flavor. Moreover, numerous post-harvest product management factors, including product type, aging length and conditions, cookery methods, product enhancement, muscle-specific factors, packaging, retail display factors, and antimicrobial interventions, have all been evaluated for their impact on beef flavor characteristics. Results from numerous studies evaluating many of these factors will be outlined within this review in order to present management and production chain factors that can influence beef flavor.

Descriptive beef flavor and texture attributes relationships with consumer acceptance of US light beef eaters

Consumer acceptance and overall liking has been shown to be related to beef instrumental and trained sensory attributes related to beef flavor, tenderness, and juiciness. Our objective was to understand the relationships between descriptive beef flavor and texture attributes, Warner-Bratzler shear force (WBSF), and consumer liking attributes for light US beef eaters. It is not known if light beef eaters have different drivers of overall liking. Treatments were created to differ in beef flavor and texture by utilizing different beef cuts (Choice top loin, high pH top loin, Select top sirloin, Choice tenderloin steaks, and Select and Choice bottom rounds roasts) cooked to 58 °C or 80 °C. Cooking methods included either a George Forman grill, food-service grill, or crock-pot. Cooking method, cut, and internal temperature impacted beef descriptive flavor and texture attributes, WBSF and consumer liking ratings (P ≤ 0.05) similarly. Descriptive juiciness and tenderness attributes were highly related to each other and with consumer juiciness and tenderness liking ratings. Consumer overall liking was closely related to descriptive fat-like, overall sweet, sweet and salty attributes. Musty/moldy, liver-like, and sour aromatic attributes were negatively associated with consumer liking. Overall flavor accounted for 85% of the variation in overall liking and tenderness liking contributed an additional 4%. While light beef eaters used different parts of the scale, they rated beef across treatments similarly. When beef flavor and texture descriptive attributes differed, consumer liking was impacted for light beef eaters.

Using untargeted metabolomics and volatile aroma compounds to predict expert sensory descriptors and consumer liking of beef loin steaks varying in quality grade, aging time, and degree of doneness

Precursors to flavor are important to its development, yet little is known about the intrinsic products of metabolism that influence flavor. Our objective was to use untargeted metabolomics and volatile aroma compounds to predict expert and consumer sensory traits. USDA Select and upper 2/3 Choice beef strip loins were wet aged for 10 or 20 d and then cut into steaks, vacuum-packaged, and frozen. Steaks were cooked to 63 °C, 71 °C, or 80 °C end-point internal steak temperature. USDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors compared to USDA Select 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. Steaks cooked to either 63 °C or 71 °C had more intense bloody, metallic, and sour flavors and were juicier, more tender, and had less connective tissue than steaks cooked to a higher degree of doneness. Volatile aroma compounds increased (P < 0.05) in Choice steaks aged for 20 d, while cooking steaks to 80 increased aldehydes, ketones, and pyrazines. Raw steaks had 69 small-molecule metabolomic compounds shared across all four quality grade x aging combinations, and discriminant analysis correctly categorized (P < 0.05) these metabolites. Metabolites and volatiles can be used to predict (r2 > 0.85) expert and consumer sensory panel descriptors and liking.

Small genetic variation affecting mRNA isoforms associated with marbling and meat color in beef cattle

The aim of this study was to identify mRNA isoforms and small genetic variants that may be affecting marbling and beef color in Nellore cattle. Longissimus thoracis muscle samples from 20 bulls with different phenotypes (out of 80 bulls set) for marbling (moderate (n = 10) and low (n = 10) groups) and beef color (desirable (n = 10) and undesirable (n = 9) group) traits were used to perform transcriptomic analysis using RNA sequencing. Fourteen and 15 mRNA isoforms were detected as differentially expressed (DE) (P-value ≤ 0.001) between divergent groups for marbling and meat color traits, respectively. Some of those DE mRNA isoforms have shown sites of splicing modified by small structural variants as single nucleotide variant (SNV), insertion, and/or deletion. Enrichment analysis identified metabolic pathways, such as O2/CO2 exchange in erythrocytes, tyrosine biosynthesis, and phenylalanine degradation. The results obtained suggest potential key regulatory genes associated with these economically important traits for the beef industry and for the consumer.

Thermophysical properties of beef steaks varying in USDA quality grade and internal temperature

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, 25, 55, 60, 71, 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 &gt; 0.05). Steaks tempered to 25°C had the greatest conductivity compared to 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 &lt; 0.001). Raw (4 and 25°C) ST steaks had lower enthalpy values compared to raw PR and LC steaks (P &lt; 0.05). Raw steaks had greater surface myosin and both center and surface actin enthalpy values (P &lt; 0.05). A quality grade × internal temperature was observed for surface and center viscoelasticity (P &lt; 0.05). Raw steaks were less viscoelastic compared to cooked steaks, regardless of quality grade (P &lt; 0.05). Quality grade and internal temperature impacted expressible moisture and water holding capacity (P ≤ 0.001). ST steaks possessed increased expressible moisture and water holding capacity compared to LC and PR steaks (P &lt; 0.05). A quality grade × internal temperature was observed for Warner-Bratzler shear force and springiness (P ≤ 0.008). DOD impacted all texture profile analysis attributes (P &lt; 0.05). PR steaks were more cohesive than ST steaks (P = 0.011). These data show that final internal temperature and intramuscular fat content impact thermophysical properties of beef steaks.

Quality of Plant-Based Ground Beef Alternatives in Comparison with Ground Beef of Various Fat Levels

The objective of this study was to compare the quality characteristics of current plant-based protein ground beef alternatives (GBA) to ground beef (GB) patties of varying fat percentages. Fifteen different production lots (n = 15/fat level) of 1.36 kg GB chubs of 3 different fat levels (10%, 20%, and 27%) were collected from retail markets in the Manhattan, KS area. Additionally, GBA products including a foodservice GBA (FGBA), a retail GBA (RGBA), and a traditional soy protein–based GBA (TGBA) currently available through commercial channels were collected. Consumers (n = 120) evaluated sample appearance, juiciness, tenderness, overall flavor liking, beef flavor liking, texture liking, and overall liking. Additionally, samples were evaluated for color, texture profile, shear force, pressed juiciness percentage (PJP), pH, and fat and moisture percentage. All 3 GB samples rated higher (P &lt; 0.05) than the 3 GBA samples for appearance liking, overall flavor liking, beef flavor liking, and overall liking by consumers. Similar results were found with trained sensory panelists, which rated the GBA as less (P &lt; 0.05) juicy, softer (P &lt; 0.05), and lower (P &lt; 0.05) for beef flavor and odor intensity and higher (P &lt; 0.05) for off-flavor intensity than the GB. Moreover, the GBA had less (P &lt; 0.05) change in shape through cooking and a lower (P &lt; 0.05) percentage of cooking loss and cooking time than the GB. Also, the GBA all had lower (P &lt; 0.05) shear force and PJP values than the GB. The color of the GBA differed (P &lt; 0.05) from the GB, with the GB samples being more (P &lt; 0.05) red in the raw state. These results indicate that the GBA provide different eating and quality experiences than GB and should thus be considered as different products by consumers and retailers.

Biochemical Factors Affecting East Asian Consumers’ Sensory Preferences of Six Beef Shank Cuts

The objective of this study was to evaluate biochemical factors affecting Warner-Bratzler shear force (WBSF) and East Asian consumers’ eating preferences of 6 different beef shank cuts cooked by moist heat. Six different beef shank muscles were collected from 12 USDA Choice beef carcasses (N = 72). Shank cuts from the left sides were cooked with moist heat and used for East Asian consumer sensory evaluation and WBSF, and shank cuts from the right sides were left uncooked and used for biochemical analysis and visual panels utilizing the same group of consumers. A correlation analysis was conducted to determine the driving factors that contributed to WBSF and East Asian consumers’ overall liking for beef shanks. Biceps brachii and flexor digitorum superficialis-pelvic received the greatest sensory overall liking, with deep digital flexor from the foreshank having the lowest scores (P &lt; 0.01). Deep digital flexor from the foreshank had the greatest WBSF value, most cooked collagen content, and greatest insoluble collagen percentage as well as the greatest raw and cooked pyridinoline (PYD) densities among all the beef shank cuts (P &lt; 0.05). For visual overall liking, shank cuts at approximately 700–750 g such as biceps brachii and extensor carpi radialis received the highest ratings (P &lt; 0.01), and consumers indicated that there was no visual difference in surface color among the shank cuts (P &gt; 0.10). Correlation analysis showed that cooked collagen content and insoluble collagen percentage as well as raw PYD densities had positive correlations with WBSF (P &lt; 0.05) and negative correlations with consumer overall liking (P &lt; 0.01). Surprisingly, collagen content from uncooked shank cuts did not have a direct relationship with consumers’ overall liking nor with WBSF. The results demonstrated that raw PYD density may be a great indicator for cooked beef tenderness in beef cuts with a high concentration of connective tissue prepared with moist heat cookery.

Do Published Cooking Temperatures Correspond with Consumer and Chef Perceptions of Steak Degrees of Doneness?

The objective of this study was to assess consumer and chef perceptions and knowledge of beef degrees of doneness (DOD) as well as to measure the changes in cooked color over time related to DOD. Steaks from strip loins (M. longissimus lumborum) from each of 5 quality treatments were used for this study. Steaks were cooked to an endpoint temperature of either very-rare (54°C), rare (60°C), medium-rare (63°C), medium (71°C), well-done (77°C), or very well-done (82°C). L*, a*, and b* were evaluated at 0, 1, 2, 3, 6, 9, and 12 min post-cutting and digital pictures were taken immediately on an internal surface of the steak. Digital surveys for the evaluation of the images of the cooked steaks were created for consumers and chefs. There were time × DOD interactions (P < 0.05) for L*, a*, and b* values. For very-rare, rare, medium-rare, and medium, a* values increased (P < 0.05) over time. For L*, well-done and very well-done steaks became darker (P < 0.05) and very-rare, rare, and medium-rare steaks became lighter (P < 0.05) over time. Surveys indicated consumers determine DOD when cooking beef in their home primarily by using color, whereas chefs primarily use touch to determine DOD. There were no quality grade effects (P > 0.05) for DOD responses for steak pictures evaluated by consumers or chefs. Consumers identified the DOD of cooked steaks as the DOD that corresponds to published end-point temperatures 27 to 35% of the time. Chefs typically identified the DOD as 1 DOD higher than which the steaks were cooked for steaks cooked to medium or less and 1 DOD lower for steaks cooked to well-done and higher. This indicates differences exist in the perceptions of DOD between culinary professionals and consumers, and may contribute to decreased consumer satisfaction when ordering steaks in a restaurant.

Visual Degree of Doneness Impacts Beef Palatability for Consumers with Different Degree of Doneness Preferences

The objective of this study was to determine the impact on beef palatability perceptions when consumers with varying degree of doneness (DOD) preferences are served steaks cooked to multiple DOD. Paired Low Choice strip loin steaks were randomly assigned to a DOD of either rare (60°C), medium-rare (63°C), medium (71°C), medium-well (74°C), or well-done (77°C). Consumer panelists were prescreened for DOD preference (rare, medium, or well-done) prior to sensory panels and were assigned to panels based on their DOD preference. In the first round of testing, consumers were served 1 sample from each of the 5 DOD under low-intensity red incandescent light to mask any DOD differences among samples. In round 2 of testing, consumers were fed the paired samples cooked to the same DOD under white incandescent lights. There were no (P > 0.05) consumer DOD preference × steak DOD interactions or consumer DOD preference effects for tenderness, juiciness, and flavor ratings when steaks were evaluated under both lighting types. Within the white-lighting testing, there was a consumer DOD preference × steak DOD interaction (P < 0.05) for overall acceptability. Consumers who preferred steaks cooked to well-done reported no differences (P > 0.05) in overall palatability among DOD under white-lighting, whereas consumers who preferred steaks cooked to rare and medium rated steaks lower (P < 0.05) for overall palatability as DOD increased. Regardless of DOD preference, consumer sensory ratings decreased (P < 0.05) when steaks were cooked above the consumer’s preferred DOD; whereas sensory ratings improved (P < 0.05) when steaks were served below the consumers’ preferences. These results indicate that overcooking steaks has the greatest negative impact on beef palatability perception and thus, foodservice should err on the side of undercooking steaks to preserve, and potentially improve, eating satisfaction.

Evaluation of Beef Top Sirloin Steaks of Four Quality Grades Cooked to Three Degrees of Doneness

The objective of this study was to evaluate the impact of USDA quality grade on beef eating quality of top sirloin steaks when cooked to multiple degrees of doneness (DOD). Beef top sirloin butts (N = 60; 15/quality grade) were collected to equally represent 4 quality grades [Prime, Top Choice (modest00 to moderate100), Low Choice, and Select]. Steaks were assigned to 1 of 3 DOD: rare (60°C), medium (71°C), and well-done (77°C). Steaks were allocated to either consumer sensory analysis, trained sensory analysis, fat and moisture analysis, or Warner-Bratzler shear force (WBSF). There were no interactions (P > 0.05) for all consumer ratings of palatability traits, indicating increases in DOD had the same impact across all quality grades. Prime steaks had greater (P < 0.05) juiciness ratings than all other quality grades, except for Top Choice. As DOD increased, consumer ratings and the percentage of steaks rated acceptable for each palatability trait decreased (P < 0.05; rare > medium > well-done). There was a quality grade × DOD interaction (P < 0.05) for trained sensory panel juiciness scores. When cooked to medium, Prime and Top Choice steaks were rated higher (P < 0.05) for juiciness than Low Choice and Select steaks, while there were no differences at all other DOD. Similar to consumer ratings, trained panel ratings of tenderness decreased (P < 0.05) as DOD increased (rare > medium > well-done). Lastly, there was no quality grade by DOD interaction (P > 0.05) for Warner-Bratzler shear force. These results indicate that regardless of the DOD top sirloin steaks are cooked to, quality grade had minimal impact on palatability. Therefore, it is unnecessary for consumers, retailers, and foodservice to pay premium prices for higher quality top sirloin steaks, as the same eating experience will be provided.

The effects of the LIPEX finishing diet regimen on pork quality, fatty acid profile, palatability, and color stability

The objective of this study was to determine the effects of the LIPEX finishing diet regimen on pork chop n-3 polyunsaturated fatty acid (PUFA) content and fresh meat quality. Twenty-eight finishing pigs (PIC 359 × F1 Hermitage/NGT; initial BW 81.5 ± 2.55 kg) were subjected to a 49-d feeding trial. Treatments consisted of a 2 × 2 factorial design with Sex (n = 14 barrows and gilts each) and Diet as main effects. Dietary treatments consisted of a 2-phase standard finishing diet regimen or a 2-phase LIPEX finishing diet regimen (EXL Milling, Lloydminster, SK, Canada). The LIPEX diet regimen added the EXL LIPEX.FA369 additive during phase 1 and the EXL LIPEX.FA369 and XFE Omega-3 Finishing Touch during phase 2. Five-days postmortem, whole boneless pork loins were transported to the Kansas State University Meats Laboratory, aged 14 d, and halved immediately behind the spinalis dorsi. After blooming for 30 min, chops were evaluated for Japanese color score and National Pork Producers Council (NPPC) color and marbling scores. A 2.54-cm chop was taken immediately anterior to the loin cut and was used for fatty acid and proximate composition analyses. Four 2.54-cm chops were cut from the posterior portion of the loin and were utilized for a 7-d simulated retail display analyses, Warner-Bratzler shear force (WBSF), and trained sensory panel. There were no Sex × Diet interactions for all variables measured in the study (P > 0.10). The LIPEX finishing regimen increased chop C18:3n-3, C20:5, and C22:5, which decreased the n-6:n-3 ratio (P < 0.01). There were no Diet effects on pH, Japanese and NPPC color and marbling scores, and proximate composition (P > 0.23). Diet did not affect cook loss, WBSF, and trained sensory panel scores (P > 0.012). There were no 2- or 3-way interactions between Diet, Sex, and Day, or Diet and Sex main effects for L*a* values, surface oxy- and metmyoglobin percentages, or visual panel chop redness and surface discoloration scores (P > 0.14). Feeding the LIPEX finishing diet regimen increased chop n-3 PUFA content without negatively impacting fresh chop palatability or color stability.