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 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 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 P<0.05 was used. For descriptive sensory analysis, an interaction was observed for beef identity, bloody/serumy, fat-like, liver-like, bitter, sour, and musty/earthy (P<0.05). Loins aged for 56 d at 4°C were the most intense for liver-like, sour, and musty/earthy notes compared with all other treatments (P<0.05). An interaction was observed for consumer juiciness, tenderness, and overall liking (P<0.05). Steaks from loins aged for 14 d at −2°C were rated the least for juiciness, tenderness, and overall liking (P<0.05). Ethanol, acetic acid,1-penten-3-ol, and 2-methylbutanal were each greatest in loins aged for 56 d (P<0.05). Aging at 4°C yielded the greatest concentrations of ethanol and heptanoic acid (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.

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<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 with LC and PR steaks (P<0.05). A quality grade×internal temperature was observed for Warner-Bratzler shear force and springiness (P ≤ 0.008). Internal temperature impacted all texture profile analysis attributes (P < 0.05). PR steaks were more cohesive than ST steaks (P = 0.011). These data show that final internal temperature and USDA quality grade impact thermophysical properties of beef steaks.

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.