85 research outputs found

    A Survey of Microbial Communities on Dry-Aged Beef in Commercial Meat Processing Facilities

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    Many artisanal meat professionals believe that the microbial populations on the outer crust of dry-aged beef contribute to variation in sensory profiles; however, to date there is minimal information about the microbes themselves that grow on commercially produced dry-aged beef. The microbiome of dry-aged beef bone-in strip loins (Institutional Meat Purchase Specifications #175) from 5 commercial dry aging facilities, including one utilizing ultraviolet light treatment, were surveyed to assess the microbial populations residing on and within each subprimal. Each strip loin was sampled at multiple spatial locations and depths, and the microbial sequences present in the samples were identified using a nextgeneration sequencing approach. Insufficient microbial DNA was isolated from ultraviolet-light-treated strip loins, indicating that this treatment eliminates all or most microbial growth on the meat. Sequencing results indicated that each establishment was producing meat with different microbial communities, based on Permutational Multivariate Analysis of Variance (P < 0.01) and clustering in the Principal Coordinates Analysis plot of Jaccard distances. The position on strip loins from which samples were taken had negligible influence on microbial community structure. Aging facility, and the relative unique environmental conditions within, was determined to be the only observed driver of community structure. Notable operational taxonomic units (OTUs) detected included the spoilage-associated bacterium Pseudomonas fragi and the fungal species Debaryomyces udenii and Penicillium polonicum. An OTU identified as Mucor sp. PG272 was found to be present in over 75% of all samples. This OTU may represent a species similar to Thamnidium, a mold that has been associated with product quality. This study established a general core microbiome for dry-aged beef observed in commercial facilities, variations of which may—as future research could indicate—contribute to distinct sensory properties

    Distribution of Marbling Throughout the M. Longissimus Thoracis et Lumborum of Beef Carcasses Using an Instrument-Grading System

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    Beef Loin, Strip Loins (IMPS #180; n = 20) with marbling scores between Modest00 and Modest30 at the 12th and 13th rib interface of the M. longissimus thoracis et lumborum (LL) were collected. Each strip loin was fabricated into 6 samples taken perpendicular to the long axis of the LL from the 13th thoracic vertebra to the fifth lumbar vertebra with the cut made on the anterior side of the respective vertebra. A Computer Vision System Cold Camera measured the LL cross-section of each sample location for USDA marbling score, marbling distribution, average marbling fleck size, LL area, LL length (distance medial to lateral), and LL width (distance dorsal to ventral). In the present study, mean LL marbling score decreased (P < 0.05) from the second lumbar vertebrae location to the fifth lumbar vertebrae location. Marbling size and marbling distance were the smallest (P < 0.05) in samples from the 13th thoracic vertebrae location. The LL area and width was largest (P < 0.05) for the samples from the most anterior location and thus decreased (P < 0.05) as the samples became more posterior. Samples from the most posterior end of the strip loin were the longest (P < 0.05) in length. It was observed that marbling score, distribution, and size, as well as, LL area, length, and width vary from anterior to posterior in the strip loin which can have potential marketing implications for food service distributors and retailers

    Assessment of dry-aged beef from commercial aging locations across the United States

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    Modern dry-aging is a culinary-inspired practice that involves storing meat at refrigerated temperatures without protective packaging. The dry-aging process has been observed to create unique flavors. The objective of the current study was to survey commercial dry-aging facility environments and observe palatability differences related to consumer acceptance. Seventy-two bone-in beef strip loins (Institutional Meat Purchase Specification #175) were acquired. Strip loins were randomly assigned to each of ten commercial dry-aging facilities. Additionally, a set of strip loins were wet-aged at the University of Idaho meat laboratory. Strip loins were shipped overnight to respective aging locations and dry-aged for 45-days then returned overnight to the University of Idaho meat laboratory. Strip loins were fabricated into steaks, vacuum packaged, and then frozen until further analyzed. Commercial dry-aging facility cooler conditions were observed to be different (P 0.05) among treatment-locations. Consumer taste panels indicated a difference (P < 0.01) in acceptability (6.27–7.24), tenderness (6.65–7.54), and flavor (5.58–6.79) based on aging treatment-location. Overall, the findings indicate that conditions within individual dry-aging facilities aid in producing unique dry-aged beef flavors.Funded by the Idaho Beef Council. We gratefully acknowledge Idaho Beef Council’s financial support (AG3963

    Muscle Profiling of the Biceps Femoris, Gluteus Accessorius, and Gluteus Medius Comprising the Beef Top Sirloin Butt

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    Muscle profiling improves value and optimization of beef carcasses by expanding knowledge of physical, com-positional, and marketable attributes of single-muscle cuts. Extensive profiling for individual muscle portions of the NAMI #184 beef top sirloin butt remains understudied. The objective was to compare fluid loss, objective color (L*, a*, b*), pH,and objective tenderness of the biceps femoris (BF), gluteus accessorius (GA), gluteus medius, dorsal (GMD), and gluteus medius, ventral (GMV). Beef top sirloin butts (N=70) were collected from carcasses ranging in quality grade (USDA Select and Top Choice), hot carcass weight (light≤362 kg, medium=363 to 453 kg, heavy≥454 kg), and ribeye area (REA; small≤27.8 cm2, medium=27.9 to 40.6 cm2, large≥40.7 cm2). Warner-Bratzler shear force values were the low-est for the BF and GA (P&lt;0.001) and were significantly different than the GMD and GMV. The GA reported the lowest percentage of fluid loss in raw and cooked forms (P&lt;0.001, P&lt;0.001) and the highest pH (P&lt;0.001). The GMD exhibited the highest percentage of raw purge (P&lt;0.001), highest L* value (P&lt;0.001), and highest shear force (P&lt;0.001). The GMV had the highest percentage of cook loss (P&lt;0.001). USDA Top Choice muscles were more tender than Select (P&lt;0.001) with higher L* value (P&lt;0.001). All 4 top sirloin muscles and muscle subunits had average peak shear force values below 3.9 kg, and thus, all were within the threshold for USDA “very tender.” These muscle profiling data will aid in identifying new beef value cuts from the top sirloin butt and assess acceptability of sirloin cuts for further retail and foodservice merchandising opportunities

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

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    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 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

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    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) 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

    Extending the Shelf Life of Beef Steaks Using Acerola Cherry Powder and Rosemary Extract

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    Improvements in retail shelf life of exported beef will help with merchandising and increase competitiveness in the worldwide market for United States beef products. The objective of this study was to determine the effect of topically applying acerola cherry powder or rosemary extract from various suppliers on beef bone-in short rib steak and chuck roll steak shelf life. USDA Choice beef bone-in short ribs (IMPS 123A) and chuck rolls (IMPS 116A) were aged (0°C) for 28 d postfabrication. Following aging, 1.02-cm-thick steaks were cut (N = 126) and systematically assigned to a treatment based on steak location within the subprimal. Treatments included untreated control (C), topically sprayed (2 mL) with an acerola cherry powder solution (0.05%) from 1 of 3 suppliers (C1, C2, C3), or topically sprayed (2 mL) with a rosemary extract solution (0.10%) from 1 of 3 suppliers (R1, R2, R3). Half of the steaks were assigned to day 0 lipid oxidation, metmyoglobin-reducing activity (MRA), and oxygen consumption; the remaining steaks were assigned to color evaluation over 4 d of retail display followed by day 4 lipid oxidation and MRA. Short rib steaks treated with antioxidants had a brighter oxygenated lean color than control steaks (P &lt; 0.001). There was an interaction (P = 0.028) between time of retail display and MRA. Short rib steaks treated with C3 and R2 did not change in MRA between day 0 and 4 (P = 0.620, P = 0.428, respectively). Chuck roll steaks treated with C1, C2, C3, R2, and R3 all had a higher, or more desirable, MRA than the control steaks on day 0 (P &lt; 0.001). Applying topical antioxidants improves the shelf-life stability of steaks from beef bone-in short ribs and chuck rolls aged for an extended period
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