RESUMEN
A high event period (HEP) occurs when beef processing facilities experience an elevated rate of STEC positive trim samples. In order to avoid contaminated vacuum-packaged beef entering into commerce, primals and subprimals associated to positive trim must be treated with antimicrobials, repackaged, and retested for STEC to ensure product wholesomeness. In this study, we evaluated the efficacy of Bacteriophages (P), Peroxiacetic Acid (PAA), Acidified Sodium Chlorite (ASC), and Ultraviolet light (UV) to reduce the O157:H7 and the Big Six STEC in beef after a simulated HEP scenario. In vacuum conditions and under aerobic conditions, phage applications and a combination of P + UV led to the greatest STEC reduction, respectively (P < 0.001). Overall, treatments including bacteriophage provided best reductions when compared to non-phage treatments (P < 0.001, for both vacuum and aerobic conditions). Bacteriophage solutions provided improved control of STEC O157:H7 and the Big Six serotypes when reworking beef after a simulated HEP scenario.
Asunto(s)
Bacteriófagos , Escherichia coli O157 , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Microbiología de Alimentos , Serogrupo , Rayos UltravioletaRESUMEN
Exploring alternative supplementation sources capable of maximizing feed and water efficiency in nursing Holstein calves is often ignored. The goals herein involve investigating the effects of two isoenergetic supplements on a nonmedicated milk replacer diet on total water intake, milk water intake, fresh water intake, feed intake parameters, and performance of Holstein nursing bull calves. Twenty-three animals (body weight [BW] = 94.67 ± 12.07 kg, age = 67 days old) were randomly assigned to one of three treatments for 68 days: control (CON; ad libitum milk replacer, n = 7), carbohydrate supplement (CHO; corn starch on top of ad libitum milk replacer-based diet, n = 8), or lipid supplement (FAT; menhaden fish oil on top of ad libitum milk replacer-based diet, n = 8). The isoenergetic supplementation consisted of 3% menhaden fish oil addition on DM basis for FAT. This was matched energetically with corn starch for the CHO group resulting in a 7% composition in DM basis. All animals were provided free access to mineral mix and 120 g daily dried microbrewer's spent grains (BG). Data were analyzed with the GLMMIX procedure of SAS in a completely randomized design with the diets as a fixed effect. Dry matter intake (DMI) adjusted by average daily gain (ADG; DMI/ADG) resulted in significantly lower values for supplemented groups with CON = 2.48, CHO = 2.38, and FAT = 2.27 kg/kg (ADG) (P = 0.033). Energy intake values were lower for CON when analyzing metabolizable energy intake (P < 0.0001), net energy intake for maintenance (P < 0.0001), and net energy intake for gain (P < 0.0001), followed by CHO, and then FAT. Total water intake (P < 0.0001), milk water intake (P < 0.0001), and fresh water intake (P < 0.0001) all resulted in CHO consuming 0.5 L or less water than the other two treatments. Energy requirements as digestible energy (P < 0.0001), metabolizable energy (P < 0.0001), net energy for maintenance (P < 0.0001), and net energy for gain (P < 0.0001) were lower for CHO, followed by CON, and then FAT having the highest requirements. Similar results were observed for residual feed (RFI; P = 0.006) and residual water intakes (RTWI; P = 0.902). Ultimately, no performance differences were detected with regards to BW (CON = 146.71, CHO = 146.25, and FAT = 150.48 kg; P > 0.1). These results indicate that lipid-based and starch-based supplementation can potentially increase feed efficiency and decrease voluntary water intake without adversely affecting performance.
RESUMEN
Research has suggested that the incidence of Salmonella in ground beef may be associated with contaminated lymph nodes that are not removed from trimmings destined for grinding. In this study, we tested the application of bacteriophages and peroxyacetic acid solutions on trimmings and on coarse and fine ground beef to simulate different scenarios of contamination. Overall, peroxyacetic acid applications did not reduce Salmonella loads on ground beef when applied on trimmings or at any stage of grinding. When applied on contaminated trim, bacteriophage solutions at 1 × 108 PFU/g and 1 × 109 PFU/g reduced more than 1 log cfu/g of Salmonella. When applied directly on contaminated coarse or fine ground beef, bacteriophage solutions at 1 × 109 PFU/g reduced approximately 1.6 log cfu/g. Results of this study suggest that bacteriophage applications on contaminated, comminuted beef may be used as an aid to decrease Salmonella loads.
Asunto(s)
Bacteriófagos , Productos de la Carne/microbiología , Ácido Peracético/farmacología , Salmonella/efectos de los fármacos , Animales , Bovinos , Desinfectantes/farmacología , Manipulación de Alimentos/métodos , Microbiología de AlimentosRESUMEN
According to the United States Food and Drug Administration (FDA) agency, bacteriophage solutions targeting the serotype O157:H7 are Generally Recognized as Safe (GRAS) to control STEC during beef processing. However, outbreaks involving the "Big Six" STEC increased the industry concern about those serotypes. The objective of this study was to test the efficacy of MS bacteriophages to reduce the "Big Six" non-O157 STEC in beef. The lysing efficacy of phages isolated for each specific serotype varied from 96.2% to 99.9% in vitro. When applied to contaminated trim, reductions ranging from 0.7 to 1.3 Log of all STEC were observed in ground beef. Bacteriophages may provide an additional barrier against the "Big Six" STEC in ground beef. Results of this research provide support documentation to the FDA to extend GRAS status for bacteriophages as processing aids against all adulterant STEC.
Asunto(s)
Bacteriófagos , Escherichia coli O157/virología , Productos de la Carne/microbiología , Escherichia coli Shiga-Toxigénica/virología , Animales , Agentes de Control Biológico , Bovinos , Microbiología de Alimentos , Inocuidad de los Alimentos/métodos , SerogrupoRESUMEN
After High Event Periods, beef subprimals are usually removed from vacuum and treated with antimicrobials. After re-packaging, subprimals are tested to verify the presence of STEC. In this study, bacteriophage and organic acids were applied on beef contaminated with STEC O157:H7 to evaluate the efficiency of industry practices. Beef samples inoculated with STEC were treated with bacteriophage, lactic acid, and peroxyacetic acid and kept under vacuum or aerobic conditions. STEC loads were evaluated 30 min and 6 h after antimicrobial applications. Under aerobic conditions for 30 min and 6 h, phage reduced STEC in beef by approximately 1.4 log whereas organic acids led to a 0.5 log reduction. Under vacuum for 30 min, bacteriophage significantly reduced STEC by 1 log. No effects were observed when samples were treated with organic acids. Under vacuum after 6 h, bacteriophage reduced STEC loads by 1.4 log, lactic acid reduced by 0.6 log, and no effects were observed when peroxyacetic acid was applied.
Asunto(s)
Antiinfecciosos/farmacología , Caudovirales/fisiología , Escherichia coli O157/efectos de los fármacos , Escherichia coli O157/virología , Carne Roja/microbiología , Animales , Bovinos , Manipulación de Alimentos/métodos , Microbiología de Alimentos , Ácido Láctico/farmacología , Ácido Peracético/farmacología , VacioRESUMEN
This research evaluated the effects of different antioxidants on overall quality of beef patties from steers fed distillers grains. Crossbred steers (nâ¯=â¯24) were fed corn, 40% Dry distillers grains plus solubles, or 40% modified distillers grains plus solubles - Dry Matter basis). Patties were made from ground chuck of individual animals and 4 antioxidant treatments were evaluated (CONTROL - no antioxidant, 0.3% ROSEMARY, 0.25% ACEROLA, and 0.6% CITRUS). Diets minimally affected quality attributes. Patties treated with ROSEMARY were shown significant lighter in color than other treatments on day 6. Patties treated with CITRUS were the reddest on days 5 and 6 of display. ACEROLA and CITRUS provided better lipid stability during display when compared to CONTROL and ROSEMARY. Treatment CITRUS reduced APC growth by 2 log when compared to all other treatments (Pâ¯<â¯0.01). Although patties treated with CITRUS had higher off-flavor intensity, no effect was observed for overall desirability. Patties treated with 0.6% of CITRUS provided optimal overall quality.
Asunto(s)
Alimentación Animal/análisis , Antioxidantes , Conservación de Alimentos/métodos , Productos de la Carne/análisis , Adulto , Animales , Bovinos , Citrus/química , Dieta/veterinaria , Grano Comestible , Femenino , Humanos , Masculino , Malpighiaceae/química , Productos de la Carne/microbiología , Persona de Mediana Edad , Extractos Vegetales/química , Rosmarinus/química , GustoRESUMEN
Inclusion of legume in grass pastures optimizes protein values of the forage and promotes improved digestibility. Therefore, we hypothesized that finishing steers on a novel combination of legumes and grass pasture would produce carcasses with acceptable traits when compared to carcasses from steers finished in feedlot systems. In this study, we evaluated the effects of finishing steers on three systems including: grazing legume-grass pasture containing oats, ryegrass, white and red clover (PAST), grazing PAST plus supplementation with whole corn grain (14 g/kg BW (SUPP)), and on a feedlot-confined system with concentrate only (28 g/kg BW, consisting of 850 g/kg of whole corn grain and 150 g/kg of protein-mineral-vitamin supplement (GRAIN)) on growth performance of steers, carcass traits and digestive disorders. Eighteen steers were randomly assigned to one of three dietary treatments and finished for 91 days. Data regarding pasture and growth performance were collected during three different periods (0 to 28, 29 to 56 and 57 to 91 days). Subsequently, steers were harvested to evaluate carcass traits, presence of rumenitis, abomasitis and liver abscesses. The legume-grass pasture provided more than 19% dry matter of protein. In addition, pasture of paddocks where steers were assigned to SUPP and PAST treatments showed similar nutritional quality. When compared to PAST, finishing on SUPP increased total weight gain per hectare, stocking rate, daily and total weight gains. The increase of weight gain was high to GRAIN than SUPP and PAST. Steers finished on GRAIN had high hot carcass weight, fat thickness and marbling score when compared to PAST. However, these attributes did not differ between GRAIN and SUPP. Abomasum lesions were more prevalent in steers finished on GRAIN when compared to PAST. Results of this research showed that it is possible to produce carcasses with desirable market weight and fat thickness by finishing steers on legume-grass pasture containing oats, ryegrass, white and red clover. Moreover, supplementing steers with corn when grazing on legume-grass pasture produced similar carcass traits when compared to beef fed corn only.
Asunto(s)
Crianza de Animales Domésticos/métodos , Bovinos/fisiología , Dieta/veterinaria , Fabaceae/química , Carne/análisis , Poaceae/química , Animales , Brasil/epidemiología , Bovinos/crecimiento & desarrollo , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/etiología , Femenino , Enfermedades Gastrointestinales/epidemiología , Enfermedades Gastrointestinales/etiología , Enfermedades Gastrointestinales/veterinariaRESUMEN
The objective of this study was to evaluate the effects of three finishing systems based on concentrate and legume-grass pasture on beef. Steers were finished for 91â¯days with an exclusively whole corn grain-based (GRAIN) diet, grazed on legume-grass pasture plus 1.4% of body weight of whole corn grain supplementation (SUPP), or grazed on legume-grass pasture (PAST) only. Lipid and myoglobin oxidation, pH, objective color, and α-tocopherol concentrations were evaluated on M. longissimus thoracis steaks. Dietary treatments did not affect pH and minimally affected protein carbonylation. Steaks from steers fed GRAIN were less red, showed higher lipid oxidation during retail display, and higher metmyoglobin formation from day 7 to 13 when compared to PAST. Levels of α-tocopherol were higher in steaks from steers fed diets containing legume and grass. Inclusion of roughage in finishing diets is essential to maintain retail color and prevent lipid and myoglobin oxidation.
Asunto(s)
Dieta/veterinaria , Fabaceae , Peroxidación de Lípido , Metamioglobina/metabolismo , Poaceae , Carne Roja/análisis , alfa-Tocoferol/metabolismo , Alimentación Animal , Crianza de Animales Domésticos/métodos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Bovinos , Color , Fibras de la Dieta , Suplementos Dietéticos , Grano Comestible , Humanos , Concentración de Iones de Hidrógeno , Masculino , Músculo Esquelético/metabolismo , Mioglobina/metabolismo , Carbonilación Proteica , Zea maysRESUMEN
Pasture-finished beef is becoming more popular among consumers due to concerns related to fatty acid content and sustainable practices. The effects of finishing crossbred steers on legume-grass pasture comprised of oats, ryegrass, and clover (PAST), legume-grass pasture plus whole corn grain (WCG) supplementation (SUPP), and only with WCG (GRAIN) on fatty acids profile, volatile compounds, sensory, and texture attributes were studied. Pasture diets (PAST and SUPP) led to lower n-6/n-3 ratio (Pâ¯<â¯0.001), and highest deposition of C18:2 cis-9 trans-11 (Pâ¯<â¯0.001) in the lean. Beef from steers fed GRAIN had the highest values of volatile compounds associated with lipid oxidation. Off-flavor intensity was significantly greater on beef from steers fed GRAIN when compared to PAST. Overall, muscles from steers finished on PAST and SUPP showed similar attributes but differ when compared to GRAIN. The presence of forage is essential to improve fatty acid profile, decrease volatile compounds associated with lipid oxidation, and minimize off-flavor.
Asunto(s)
Alimentación Animal/análisis , Ácidos Grasos/análisis , Carne Roja/análisis , Adolescente , Adulto , Avena , Dieta/veterinaria , Grano Comestible , Humanos , Lolium , Músculo Esquelético/química , Carne Roja/normas , Gusto , Trifolium , Compuestos Orgánicos Volátiles/análisis , Zea maysRESUMEN
This study investigated individual and combined effects of organic acids, bacteriophages, and ultraviolet light interventions on Salmonella populations in ground beef. Beef trim was inoculated with four Salmonella strains to result in a contamination level of 3.5 log CFU/g after grinding. Lactic (LA) and peroxyacetic (PAA) acids, bacteriophages (S16 and FO1a) (BA), and ultraviolet light (UV) were applied on fresh trim prior to grinding. Applications of individual or combined organic acids did not significantly decrease Salmonella populations in ground beef. Individual applications of BA and UV light decreased approximately 1 log CFU/g (P<0.05). Combined applications of BA and UV provided an optimal decrease of 2 log CFU/g (P<0.05). Organic acid applications do not reduce Salmonella populations in ground beef when applied on trim prior to grinding. Combined applications of UV and BA may be used in industry settings to improve Salmonella control in ground beef.
Asunto(s)
Bacteriófagos , Desinfectantes/farmacología , Productos de la Carne/microbiología , Salmonella/crecimiento & desarrollo , Rayos Ultravioleta , Animales , Bovinos , Recuento de Colonia Microbiana , Manipulación de Alimentos/métodos , Microbiología de Alimentos , Ácido Láctico/farmacología , Ácido Peracético/farmacologíaRESUMEN
The objective of this study was to evaluate the effects of feeding wet distillers grains plus solubles (WDGS) on quality attributes of three beef muscles (longissimus lumborum, psoas major, and infraspinatus). Ninety-six, yearlings crossbred steers were randomly assigned to one of three dietary treatments (Corn, 15%, or 30% WDGS - DM basis) and fed for 133 d. No significant differences were observed in marbling score (P=0.89), marbling texture (P=0.70), and marbling distribution (P=0.36). Greater concentrations of PUFA and lower levels of 18:1(n-7) were observed in beef from steers fed 30% WDGS when compared to other treatments. Lipid oxidation was also greater in beef from steers fed 30% WDGS (P≤0.05). No significant differences were observed in sensorial attributes and Warner-Bratzler shear force (WBSF) for all muscles (P>0.05). Feeding WDGS increased PUFA and lipid oxidation, which may lead to shorter shelf life.
Asunto(s)
Alimentación Animal/análisis , Dieta/veterinaria , Ácidos Grasos/análisis , Carne Roja/análisis , Animales , Bovinos , Metabolismo de los Lípidos , Masculino , Músculo Esquelético , Carne Roja/normas , Zea maysRESUMEN
The aim of this study was to evaluate the muscle profile of novel added-value beef cuts including the caudal tip of the M. infraspinatus (Bonanza Cut; TIP) and M. subscapularis (SUB) and two traditional sirloin steak cuts, M. gluteus medius (top sirloin; GLM) and M. rectus femoris (sirloin tip; REC). Samples were subjected to Warner-Braztler Shear Force (WBSF), sensory, cooking loss, and proximate analysis. The muscle TIP had superior values of subjective tenderness, juiciness, and slight off-flavor intensity when compared to all other muscles. The TIP and SUB were similar in WBSF. Cooking loss and moisture values of raw samples were lowest for TIP. Results suggest that TIP can provide enhanced eating experience for consumers and improved marketability for the meat industry.
Asunto(s)
Carne Roja/normas , Gusto , Animales , Bovinos , Culinaria , Humanos , Músculo Esquelético , Carne Roja/clasificaciónRESUMEN
Water Pocket (WP) is a defect on beef that may lead to significant economic losses. Our hypothesis is that longer spray-chilling time increases WP incidence on ribeyes (M. longissimus thoracis). Ribeyes (28,801) were visually evaluated for the presence of WP after 24 or 72h of spray chilling. Additionally, 252 beef sides were evaluated prior to chilling to predict WP development after 24h of spray chilling. Also, the 12th rib fat thickness was measured on 313 sides and the sides were assigned to two categories of WP or no WP to evaluate fat thickness as an indicator for WP. Subcutaneous fat softness is not related to WP development, longer spray-chilling does not increase the incidence of WP in ribeyes, and thinner subcutaneous fat is an indicator for WP development.
Asunto(s)
Frío , Manipulación de Alimentos/métodos , Tecnología de Alimentos , Carne Roja/análisis , Animales , Bovinos , Músculo Esquelético , Carne Roja/normas , Factores de Tiempo , AguaRESUMEN
This research was conducted to study the effects of bacteriophage application during tumbling on Salmonella populations in ground meat and poultry. Red meat trim and poultry were inoculated with a Salmonella cocktail to result in a contamination level of 7logCFU/g in ground products. A commercial preparation containing bacteriophages S16 and Felix-O1a (FO1a) was applied during tumbling at 107 and 108PFU/ml. Samples were held at 4°C for 6h and 18h (red meat) and 30min and 6h (poultry). Overall, bacteriophage application on trim reduced 1 and 0.8logCFU/g of Salmonella in ground beef and ground pork, respectively. For ground chicken and ground turkey, Salmonella was reduced by 1.1 and 0.9logCFU/g, respectively. This study shows that bacteriophage application during tumbling of red meat trim and poultry can provide additional Salmonella control in ground products.
Asunto(s)
Bacteriófagos , Manipulación de Alimentos/métodos , Microbiología de Alimentos , Inocuidad de los Alimentos/métodos , Carne/microbiología , Salmonella/crecimiento & desarrollo , Animales , Bovinos , Recuento de Colonia Microbiana , Humanos , Productos de la Carne/microbiología , PavosRESUMEN
A simple and inexpensive biosensor based on lyophilized mushroom tissue (Agaricus bisporus) was developed for amperometric determination of phenol. This fungi tissue contains tyrosinase (EC 1.14.18.1) enzyme that catalysis two sequential oxidation reactions with phenolic substrates. Both reactions involve molecular oxygen; therefore, the commercial Clark-type oxygen electrode was selected as a transducer. The lyophilized biocomponent was tested in two different forms: cubes (at two positions in the biosensor system) or powder. In characterization studies of the biosensor, some parameters such as time reaction, linear range and repeatability were investigated. For the best biosensor configuration, a linear response was observed from 0.1 to 10.0mg L(-1) phenol; variation coefficient and standard deviation were calculated as 0.02% and +/- 0.11mg L(-1), respectively.
Asunto(s)
Agaricus/química , Técnicas Biosensibles , Fenol/química , Agaricales , Calibración , Colorimetría , Electroquímica/métodos , Electrodos , Enzimas Inmovilizadas/química , Diseño de Equipo , Liofilización , Monofenol Monooxigenasa/química , Oxígeno/química , Polvos/química , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: The present study considers the production of knowledge and the interactions in the environment of research and their relationships in the system of caring in nursing and health. AIM: To elaborate a theoretical model of the organization of the practices used for caring, based on the experiences made by the research groups of administration and management in nursing, in Brazil. METHODS: The study is based on grounded theory. Twelve leaders of research groups, working as professors in public universities in the south and the south-east of Brazil, distributed in sample groups, were interviewed. FINDINGS: The core phenomenon 'research groups of administration and management in nursing: arrangements and interactions in the system of caring in nursing' was derived from the categories: conceptual bases and contexts of the research groups; experiencing interactions in the research groups; functionality of the research groups; and outputs of the research groups. The research groups are integrated in the system of caring in nursing. CONCLUSIONS: The activities of the Brazilian administration and management in nursing research groups are process oriented and in a process of constant renovation, socially relevant, operate in a complex scenario and contribute to the advancement of the organizations of the system of caring in nursing through strengthening the connection among academia, service and community.
Asunto(s)
Empatía , Investigación en Administración de Enfermería/organización & administración , Investigación Biomédica Traslacional , Brasil , Humanos , Investigación en Administración de Enfermería/métodosRESUMEN
BACKGROUND: The Epstein-Barr virus (EBV) was used as an agent of B lymphocyte proliferation for subsequent diagnosis of lysosomal storage disease. Due to the constant handling of long-preserved samples in our cell bank, we decided to observe the behavior and then compare cultured and frozen samples for at least one year's cryopreservation. METHODS: Twenty-five samples from healthy individuals were used to assess the possible changes in activity of enzymes ß-galactosidase, ß-glucosidase, α-iduronidase, α-galactosidase, and α-glucosidase. Transmission electron microscopy was used to confirm cell transformation of B lymphocytes into EBV-infected cells, generating lymphoblastoid cell lines. RESULTS: Transmission electron microscopy findings confirmed previous reports in the literature that is, significant and evident morphological changes in the nucleus occur after day 12 and the consequent cell transformation into EBV-infected cells. After thawing and subsequent treatment with the five enzymes utilized, we observed no significant changes in samples cryopreserved for more than one year, as compared to samples cultured for 12 days.
Asunto(s)
Linfocitos B/enzimología , Linfocitos B/virología , Criopreservación , Hidrolasas/metabolismo , Lisosomas/enzimología , Linfocitos B/metabolismo , Línea Celular , Transformación Celular Viral , Herpesvirus Humano 4/metabolismo , Humanos , Iduronidasa/metabolismo , Activación de Linfocitos , alfa-Galactosidasa/metabolismo , alfa-Glucosidasas/metabolismo , beta-Galactosidasa/metabolismo , beta-Glucosidasa/metabolismoRESUMEN
Whole field peas were fed at 0, 10, 20, and 30% of DM to 139 yearling steers (British cross; 409 ± 31 kg of initial BW) for a 119-d finishing period. Carcass data and Choice grade strip loins (n = 98) were collected from a commercial abattoir in Lexington, Nebraska. Consumer sensory and Warner-Bratzler shear force analyses were performed on 2.5-cm strip steaks. No differences (P ≥ 0.17) were observed in final BW, ADG, DMI, and G:F of steers. Likewise, no differences (P ≥ 0.23) were observed for HCW, LM area, fat thickness at the 12th rib, yield grade, and marbling scores. However, KPH responded quadratically to increasing dietary amount of field peas (P = 0.02). Regarding the sensorial analysis, feeding peas linearly increased subjective tenderness (P < 0.01) and led to a quadratic response of overall like ratings (P = 0.01) and flavor like ratings (P = 0.12). Feeding peas did not alter (P ≥ 0.64) juiciness, but decreased shear force values linearly when quantities were increased (P = 0.02). These data suggest that feeding peas does not affect steer performance or carcass characteristics differently from dry-rolled corn, but does improve objective and subjective tenderness, overall desirability, and flavor of beef. Field peas could be fed to cattle and give positive attributes to the quality of the meat up to 30% inclusion in the diet.
Asunto(s)
Composición Corporal , Bovinos/crecimiento & desarrollo , Dieta/veterinaria , Carne/análisis , Pisum sativum , Alimentación Animal/análisis , Animales , Bovinos/metabolismo , Masculino , Distribución AleatoriaRESUMEN
Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71 degrees C). The PT, SR, VI, and VM were grilled (71 degrees C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P < 0.05). In the SO, the tenderness decreased from the middle of the muscle to both ends (P < 0.05). The anterior sides of the long head BF and SO were tougher than their posterior sides (P < 0.05).The first 4 steaks of the SM were more tender than the rest of the muscle (P < 0.05). There was a significant tenderness increment from the middle of the AF and SR to both ends of each muscle (P < 0.05). The medial side of the VI was more tender than its lateral side (P < 0.05). The VM had its smallest shear force value at the most distal end compared with the rest (P < 0.05). Dry or moist heat oven roasting, as compared with grilling, significantly tenderized SO (P = 0.002) and VL (P < 0.0001) muscles. There were no significant WBSF value differences along the PT and between anterior and posterior regions of the GL. Based on WBSF ratings, PT, SR, VM, GL, and VI could be merchandized as single muscle steaks or medallions and the first 2 to 4 steaks of long head BF, SM, and AF could be marketed as premium-quality steaks. This detailed information on intramuscular tenderness and muscle fiber orientation variations of the round muscles could be used in a value added strategy for the beef round.
Asunto(s)
Carne/normas , Músculo Esquelético/anatomía & histología , Animales , Bovinos , Culinaria , Resistencia al CorteRESUMEN
OBJECTIVE: The Epstein-Barr virus (EBV) is utilized as a tool in the study of cellular biology because of its capacity to transform B-lymphocytes. For this reason, EBV is used in conservation of human B-lymphocytes for long periods for subsequent evaluation of lysosomal hydrolase activity. Lymphoblastoid cell lines have several advantages for use over other cell types, such as prompt availability and possibility to develop, characterize and standardize cell banks, to test effects of promising pharmaceutical reagents. The study below presents biochemical data that demonstrate validity of lymphoblastoid cell lines for diagnosis of GM1-gangliosidosis, Gaucher, Fabry and Pompe diseases and mucopolysaccharidosis type I. MATERIALS AND METHODS: Cultures were prepared from peripheral blood, collected from 25 normal subjects and 13 affected individuals. Enzyme activities and immunohistochemistry (IHC) were measured. Activities of enzymes beta-galactosidase, beta-glucosidase, alpha-iduronidase, alpha-galactosidase and alpha-glucosidase were measured before and after cryopreservation for 180 days. Enzymatic activity was measured when transformation was confirmed by IHC. RESULTS: We observed some significant alterations in enzymatic activity of non-cultured cells when compared to others that had been cultured for 12 days and kept frozen for 180 days. CONCLUSIONS: However, these alterations did not invalidate use of the technology of transformation of lymphoblastoid cell lines with EBV, to diagnose the diseases mentioned above, in view of the fact that the cultured cells, before and after freezing, demonstrated similar enzymatic activities.