Meat and Muscle Biology最新文献

{"title":"Investigation of Smoked Beef Brisket Palatability from Three USDA Quality Grades","authors":"W. T. Fletcher, A. Garmyn, J. Legako, D. Woerner, Mark F. Miller","doi":"10.22175/mmb.10963","DOIUrl":"https://doi.org/10.22175/mmb.10963","url":null,"abstract":"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.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91314437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation of Bioelectrical Impedance With Freshness Quality Attributes of Beef Longissimus Lumborum Steaks","authors":"C. Vahl, D. Vega, E. Boyle, F. Najar-Villarreal, J. Amamcharla, J. Gonzalez, J. Kastner, K. Cox, Q. Kang, T. Houser","doi":"10.22175/MMB.11704","DOIUrl":"https://doi.org/10.22175/MMB.11704","url":null,"abstract":"The quality attributes of beef longissimus lumborum during 15 d of retail display were assessed using surface bioelectrical impedance analysis (S-BIA) and internal bioelectrical impedance analysis (I-BIA). Beef loins (N = 18) were obtained from 3 commercial processors with 3 postmortem (PM) ages (27, 34, and 37 d). Loins were fabricated into twelve 2.54-cm-thick steaks, subdivided into 6 consecutively cut pairs, and randomly assigned to one of 6 display days (DD): 0, 3, 6, 9, 12, or 15. Steaks were assessed for S-BIA and I-BIA. Three locations were analyzed within each steak: top, middle, and bottom. Microbiological analysis, BIA, pH, instrumental color, proximate composition, and lipid oxidation were measured. There was a location × PM day × DD interaction (P < 0.05) for longissimus lumborum steaks for S-BIA. Among all 3 locations, steaks aged 27 d had higher (P < 0.05) S-BIA values on day 9 and 12 than steaks aged 34 and 37 d. There were no location × PM day × DD or two-way interactions (P > 0.05) for I-BIA. Display day affected (P < 0.05) all instrumental color data regardless of PM aging times. Among all PM aging times, steaks aged 27 d were 13% and 7% higher for a* and b* , respectively, compared with 34 and 37 d PM. There was a PM day × DD interaction (P < 0.05) for aerobic plate counts (APC). From day 0 and 9 of display, APC of steaks aged 27 d PM were 1 to 2.0 log colony-forming units/cm 2 lower than steaks aged 34 and 37 d. Quality attributes, including a*, b* , APC, and thiobarbituric acid reactive substances, were correlated (r = 0.70, − 0.64, − 0.56, and 0.69, respectively) with S-BIA. Overall, BIA values increased on aerobically packaged longissimus lumborum steaks and were correlated with various freshness quality parameters.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82133476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Cooking Time of Chicken Patties Prepared Using Woody Broiler Breast Meat","authors":"A. Giampietro-Ganeco, C. Owens, J. Caldas-Cueva","doi":"10.22175/MMB.11690","DOIUrl":"https://doi.org/10.22175/MMB.11690","url":null,"abstract":"This study evaluated the cooking time of chicken patties prepared with broiler breast fillets exhibiting varying degrees of woody breast (WB). Intact breast fillets (n= 90) deboned at 3 h postmortem were collected from broilers processed following commercial-based operations and categorized based on the degree of tactile hardness in 3 WB categories (normal [NOR], mild [MIL], and moderate/severe [SEV]). These tactile scores were validated using the instrumental compression force analysis. Fillet color (L*, a*, and b*) and pH were also measured at 24 h postmortem. Breast fillets were individually ground and formed into patties (patties made with NOR [P-NOR], patties made with MIL [P-MIL], and patties madewith SEV [P-SEV]). Patties were cooked from 2°C to a final center temperature of 75°C on a flat electric griddle (150° C). Internal patty temperatures were measured at 0, 1, 2, 3, and 4 min and then every 30 s until the target core temperature was reached. Cook loss and moisture content were also evaluated in cooked patties. SEV fillets showed higher (P< 0.05) compression force, pH, L*, a*, and b* values than NOR fillets. The cooking time to the terminal point was lower for P-SEV compared with P-NOR (P< 0.05). No differences were observed in cooking time between P-MIL and the other patty samples. Cook loss andmoisture content levels were greater (P< 0.05) in P-SEV in comparisonwith P-NOR and P-MIL. These results suggest that the WB condition can alter the thermal processing of chicken patties by reducing the cooking time. Further research would be needed to confirm potential alterations caused by this myopathy in thermophysical properties of intact WB fillets and further processed poultry products containing WB meat.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"134 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85024010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochemical Factors Affecting East Asian Consumers’ Sensory Preferences of Six Beef Shank Cuts","authors":"W. Wu, A. Welter, E. Rice, B. Olson, T. O’Quinn, E. Boyle, G. Magnin-Bissel, T. Houser, M. Chao","doi":"10.22175/mmb.11626","DOIUrl":"https://doi.org/10.22175/mmb.11626","url":null,"abstract":"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 < 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 < 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 < 0.01), and consumers indicated that there was no visual difference in surface color among the shank cuts (P > 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 < 0.05) and negative correlations with consumer overall liking (P < 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.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81026866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship Between Meat Quality, Carcass Characteristics, and Protein Abundance of HSPβ1, HSPA, and DJ1 in Beef Longissimus thoracis Pre-Rigor or After 14 Days’ Aging","authors":"J. Legako, Kara J Thornton-Kurth, M. MacNeil, Rachael C Christensen, R. C. Raymond, R. Briggs, S. Quarnberg","doi":"10.22175/mmb.11685","DOIUrl":"https://doi.org/10.22175/mmb.11685","url":null,"abstract":"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.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77076935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Woody Breast Myopathy on Sarcomere Length and Tensile Strength in Commercial Broiler Pectoralis major Muscle","authors":"Crisitina Costandache, E. Puolanne, P. Ertbjerg","doi":"10.22175/mmb.11564","DOIUrl":"https://doi.org/10.22175/mmb.11564","url":null,"abstract":"Woody breast syndrome is characterized by degenerative changes at the muscle fiber level and accumulation of connective tissue between the fibers. This study explored effects of the syndrome on muscle properties by focusing on a comparison of the sarcomere lengths between normal and woody breast muscles, including cranial and middle parts, surface and deeper layers, electrically stimulated and nonstimulated muscles, and their combinations. Tensile strengths longitudinally and transversally to the muscle fiber direction in the cranial and middle parts of the muscles were determined. The overall sarcomere lengths of woody breasts were longer than normal muscles (1.93 μ m vs. 1.88 μm; P < 0.05). The surface layer had overall longer sarcomere lengths than the deeper layer (cranial surface vs. cranial deeper layer: 1.97 vs. 1.89 μ m; middle surface vs. middle deeper layer: 1.93 vs.1.84 μ m; P < 0.05). Compared with normal breast muscles, woody breast muscles had longer sarcomeres in the surface layer; however, sarcomere length did not differ in the deeper layer. Electrically stimulated chicken breasts generally had longer sarcomere lengths (2.00 vs. 1.82 μm; P < 0.001). There was no significant difference in tensile strength between normal and focal woody breast (mild local lesion, usually in the cranial end) samples when fiber direction or sample location was studied (P > 0.05), but there was a clear difference between normal and focal versus diffuse (severe woody breast lesion throughout the muscle) samples (P < 0.001). Tensile strength was much greater in diffuse woody breast muscles when extended longitudinally or transversely to the fiber direction. In conclusion, although this study did not show sarcomere lengths in living muscle, it suggests an imbalance in sarcomere lengths in different parts of the breast muscle, which may induce a reduction in the functionality and strength of the muscle.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89958470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical Characterization and Sensory Relationships of Beef M. longissimus lumborum and M. gluteus medius Steaks After Retail Display in Various Packaging Environments","authors":"J. Ponce, J. Brooks, J. Legako","doi":"10.22175/mmb.10481","DOIUrl":"https://doi.org/10.22175/mmb.10481","url":null,"abstract":"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.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85767704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bone and Subcutaneous Fat Influence on Yield, Physicochemical Traits, and Color Stability of Dry-Aged Loin From Grass-Fed Nellore Bulls","authors":"A. Bernardo, C. Calkins, F. Ribeiro, S. B. Pflanzer","doi":"10.22175/MMB.11141","DOIUrl":"https://doi.org/10.22175/MMB.11141","url":null,"abstract":"The objective of the current study was to evaluate the influence of bone and subcutaneous fat on yield, physicochemical traits, and color stability of dry-aged beef from grass-fed Nellore bulls. Paired bone-in loins (from the 10th thoracic vertebra to 6th lumbar vertebra) from 8 carcasses were collected and cut in half, and the sections from each carcass were assigned to 4 treatments (n = 8): bone-in with subcutaneous fat, bone-in without subcutaneous fat, boneless with subcutaneous fat, and boneless without subcutaneous fat. Loin sections were dry-aged for 21 d, at 2°C and 70% relative humidity. After dry aging, the half-loins were weighed, trimmed, and weighed again to determine the evaporation loss, trimming loss, and yield. Additionally, water activity, pH, thiobarbituric acid-reactive substances, moisture content, cooking loss, pressed juice percentage, Warner-Bratzler shear force, and color stability (during 9 d of display) were analyzed. No interactions (P > 0.05) between bone and subcutaneous fat were found for evaporation and trimming loss, yield, and physicochemical traits. The treatments did not affect Warner-Bratzler shear force, pressed juice percentage, thiobarbituric acid-reactive sub-stances, and pH values (P > 0.05). Regarding color stability, there was a bone-by-time interaction (P < 0.05) for a* and b* parameters. Boneless treatments showed higher a* and b* values (P < 0.05) than bone-in treatments, after 6 and 7 d of display, respectively. Bone-in treatments and treatments with subcutaneous fat had lower evaporation and trimming loss and higher yield compared to boneless treatments and treatments without subcutaneous fat, respectively (P < 0.05). Therefore, although bone-in treatments showed lower color stability, bone and subcutaneous fat were considered important factors to the dry-aging process, as both resulted in a greater yield over dry-aged product that had bone and/or fat removed, without compromising other physicochemical traits of dry-aged beef from grass-fed Nellore bulls.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77531376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free Calcium Concentration, Calpain-2 Activity, and Final Product Tenderness of Electrically Stimulated Beef","authors":"Brianna J Buseman, T. Weber, J. A. Nasados, P. Bass, J. Buren, J. M. Lancaster, J. H. Smart, M. E. Doumit, G. Murdoch, W. Price, K. Insausti, M. Colle, B. J. Buseman, T. Weber, P. Bass, J. Buren, J. M. Lancaster, J. H. Smart, M. E. Doumit, G. Murdoch, W. Price, K. Insausti, M. Colle","doi":"10.22175/mmb.10635","DOIUrl":"https://doi.org/10.22175/mmb.10635","url":null,"abstract":"The objective of this study was to evaluate the effect of timing of electrical stimulation on free calcium concentration, calpain-2 activity, Warner-Bratzler shear force (WBSF), and consumer sensory analysis. Twenty-three beef steers were harvested and stimulated (S) using extra-low voltage or not stimulated (NS), at exsanguination and/or 1 h postmortem, resulting in 4 different stimulation treatments: NS-NS, NS-S, S-NS, or S-S. Samples were removed from the longissimus lumborum (LL) and semimembranosus (SM) for free calcium and calpain-2 analysis on days 1, 4, and 14 postmortem. WBSF and sensory analysis steaks were removed on day 4 and frozen (4 d) or aged to 14 d postmortem. Data were analyzed using the mixed model or generalized linear mixed model procedure of SAS (SAS Institute, Inc., Cary, NC), with significance determined at P < 0.05. There was a tendency for an aging-period-by-stimulation-treatment interaction for LL free calcium concentration (P = 0.05), and there was a significant difference between aging periods (P < 0.01). No difference was observed in free calcium concentration in the SM between stimulation treatments (P = 0.44); aging, however, significantly increased SM free calcium concentration (P < 0.01). Stimulation did not impact native calpain-2 activity in the LL (P = 0.71) or SM (P = 0.89). Stimulation treatment did not improve tenderness values for WBSF analysis for the LL (P = 0.69) or SM (P = 0.61) or consumer sensory analysis in the LL (P = 0.56) or SM (P = 0.36). A longer aging period tended to increase calpain-2 activity in the SM (P = 0.08), improve WBSF in the LL (P = 0.09), and significantly improve consumer tenderness scores in the SM (P < 0.01). In conclusion, the timing of electrical stimulation utilized in the current study tended to influence free calcium concentration in the LL but did not influence calpain-2 activity or beef tenderness. Aging, however, improved tenderness.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"2012 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86366262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bovine Somatotropin Alters Myosin Heavy Chains and Beta Receptors in Skeletal Muscle of Feedlot Heifers with Little Impact on Live or Carcass Performance","authors":"A. Thompson, B. Johnson, G. Vogel, J. Hergenreder, J. Baggerman, K. Spivey, Rand P Broadway, T. L. Harris, Z. Smith","doi":"10.22175/MMB.11137","DOIUrl":"https://doi.org/10.22175/MMB.11137","url":null,"abstract":"The objective was to determine whether recombinant bovine somatotropin (rbST) enhanced live performance,skeletal muscle biological activity, and beta-adrenergic receptor expression of feedlot heifers during the finishing phase. Heifers (n = 16; initial body weight = 457 ± 3 kg) were randomly assigned to pens (4 pens/treatment; 2 heads/pen) and treatment: (1) no rbST (Control); (2) 500 mg/hd of sometribove zinc at day 0 and 14 (rbST; Posilac®; Elanco AnimalHealth, Greenfield, IN). Longissimus muscle biopsies for muscle chemistry were collected on day 0, 14, 28, 42, and 56. The rbST heifers had increased expression of AMP-activated protein kinase alpha and beta 3 adrenergic receptor (P < 0.05). Day of the study affected the expression of myosin heavy chain-IIA (MHC-IIA), MHC-IIX, beta 2 adrenergic receptor, peroxisome proliferator-activated receptor gamma, and stearoyl-CoA desaturase (P < 0.05). Day had a significant effect on muscle fiber cross-sectional area and proportion (P < 0.05). As days on feed increased, the area of MHC-I fibers decreased whereas MHC-IIA and IIX area increased (P < 0.05). The rbST heifers had decreased proportions of MHC-I fibers and increased proportions of MHC-IIX fibers (P < 0.05). The greatest density of Paired Box 7-positive cells was on day 0, 28, and 42 (P < 0.05), and the greatest density of Myogenic factor 5-positive cells was on day 42 and 56 (P < 0.05). Also, the greatest density of cells positive for Paired Box 7:Myogenic factor 5 was measured on day 28 (P < 0.05). These data indicate that, as days on feed increase, the effects of skeletal muscle biological activity are not dependent on rbST administration but may be more due to physiological changes occurring as the animal reaches physio-logical maturity.","PeriodicalId":18316,"journal":{"name":"Meat and Muscle Biology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78442180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}