Factors affecting activity of the calcium-dependent proteases and their participation in the process of meat tenderization

The endogenous calpain system plays a major role in regulating proteolysis of muscle proteins under postmortem conditions. Substrates of calpains, such as desmin, synemin, talin and vinculin, form part of the citoskeletal framework of the muscle cell. The calpain system is composed of several isoforms of calcium-dependent cysteine proteases and their specific competitive inhibitor, calpastatin. The two best-characterized isoforms of calpains are -calpain and m-calpain, which both degrade the same specific set of myofibrillar and cytoskeletal proteins as muscle is converted into meat. Alterations in pH and/or ionic strength may cause conformational changes that allow an increase in the hydrophobicity and aggregation of the enzyme. Likewise, pH/ionic strength may alter conformation of the substrate and make them less susceptible to cleavage by -calpain. The pH optimal of the calpainas is 7.0, although, at lower pH, the enzymes show some catalytic activity. Research on this topic is abundant but results are very controversial. Temperatures of refrigeration also play a key rol in the autolysis of the calpains and calpastatin. Recent experimental evidence shows that proteolysis of key cytoskeletal proteins, such as the intermediate filament protein, desmin, may be related also to drip loss or water holding capacity of the carcass

Variations of early postmortem pH in carcasses of grass-fed steers and its relationship with glycolytic potential and meat quality traits

This study aimed to investigate the multivariate relationship between the glycolytic potential, and meat quality traits from grass-fed steers carcasses with variations in early postmortem pH. From a contemporary group of steers (n=70) from the same production unit and slaughtered under similar conditions, thirty carcasses (10/group) were selected based on pH values measured at 3h (pH3h): Low (< 6.2), Intermediate pH3h (6.2–6.5), and High (> 6.5). Carcasses segregated by pH3h groups were different (p < 0.05) in muscular glycogen (MCG), glucose (G+G6P) content, glycolytic potential (GP) and GPstrict (GP without lactate content). The interaction pH3h groups × sampling time was significant only for lactate content (LC) (p < 0.05). Quality traits, except redness, did not vary (p > 0.05) among pH3h groups. Color variables had a positive and moderate correlation with MGC, G+G6P, LC, and GP. Results does not allow to recommend early carcass segregation by very early pH (3h postmortem); however, important bivariate and multivariate relationships between G+G6P, lactate content and instrumental color parameters in LL muscle from grass-fed cattle were demonstrated

METHODS AND COMPOSITIONS TO ENHANCE TENDERNESS AND VALUE OF MEAT

A method of enhancing the tenderness of meat for animal or human consumption by treatment of pre-rigor muscle with the compositions of the invention. It has been found that other quality meat traits can also be enhanced with the method of the invention

Evaluación del método de aturdimiento y tiempo de reposo corto sobre las características de la canal y la carne de cerdo

The effect of short lairage time (SLT: ≤1h and 3 h) and two stunning methods – SM (electrical and gas) and their interaction on carcass and pork quality was evaluated. The study was carried out with 108 barrow male pigs weighing 95-100 kg. Carcass defects (ecchymosis-petechiae, bruises, bone/muscle separation in the pork chop loins and bone fractures) and meat quality traits: pH45min, pH24h, color, water holding capacity (WHC), and drip loss (DL) were determined. The SLT affected WHC (p<0.05), where the meat from animals with SLT <1h had higher water losses (24.6%) when compared to those from animals with SLT = 3h (21.3%) (p<0.05). The electrical SM caused more carcass defects (bruises, bone separation in the pork chop loins and bone fractures in pork chops) and lower WHC value (p<0.05). The bone fractures were found in a higher incidence in carcasses from electrical SM with minimal lairage time and electrical SM with 3 h of SLT. The electrical SM caused a higher incidence of carcass defects and lower WHC. The electrical SM was more predisposed to produce an incidence of defects in the carcass, in the quality of the carcass and pig meat, while the SLT treatments did not cause significant variations neither in the carcass defects nor in the quality of the meat.Se evaluó el efecto de dos tiempos de reposo corto (TRC: <1h y 3h), dos métodos de aturdimiento – MA (electronarcosis a dos puntos y gas CO2) y su interacción sobre la calidad de la canal y de la carne de cerdos. Se trabajó con 108 cerdos macho castrados de 95-100 kg. Se determinó la frecuencia de defectos en la canal (equimosis-petequias, hematomas, separación hueso/músculo en la chuleta y fractura sucia y limpia) y las características de la calidad de la carne (pH45min, pH24h, color, capacidad de retención de agua [CRA], pérdida por goteo). El TRC afectó a la CRA, donde las carnes provenientes de animales con TRC<1h tuvieron mayores pérdidas de agua (24.6%) al compararlos con las provenientes de animales con TRC=3h (21.3%) (p<0.05). Los animales sometidos a electronarcosis presentaron una mayor incidencia de defectos en la chuleta (hematomas, separación hueso/músculo en la chuleta, fractura sucia), y menor CRA (p<0.05). El MA por electronarcosis presentó mayor predisposición a producir una incidencia de defectos en la canal y en la calidad de la canal y de la carne porcina; mientras que los TRC evaluados no causaron variaciones importantes ni en los defectos de canal ni en la calidad de la carne

Avaliação do impacto dos cruzamentos Bos taurus x Bos indicus e tecnologias post mortem na qualidade gustativa de lombos de novilhos terminados a pasto

This experiment aimed to evaluate the effects of Brahman crossbreeding and postmortem technologies (electrical stimulation and vacuum aging) on eating quality of loins from pasture-finished bulls. Fifty yearling bulls representing five Brahman-influenced types (n = 10 each): Brahman (BRAH), F1-Angus (F1ANG), F1-Chianina (F1CHI), F1-Romosinuano (F1ROM), and F1-Simmental (F1SIM) were supplemented on pasture until reaching a desirable conformation at a suitable live weight of ca. 480 kg. All carcasses were classified as “Bullocks” according to U.S. standards. Carcass’s right sides were subjected to high-voltage electrical stimulation (ES) while the left sides were not stimulated (NOES). Longissimus lumborum (LL) steaks from ES and NOES carcasses were allotted either to the vacuum aging control treatment for 2 d (NOAGING) or 10 d (AGING).  LL steaks were evaluated for Warner-Bratzler shear force (WBSF) and sensory traits by trained panelists. No differences in WBSF, juiciness, or flavor ratings were detected among breed types (P > 0.05). Sensory ratings for tenderness-related traits varied little with breed type (P < 0.05). Steaks from F1ANG received higher ratings for muscle fiber tenderness, overall tenderness, and amount of connective tissue, and differed (P < 0.05) from those of F1ROM and F1SIM which received the lowest ratings. Bullock loins were more responsive to ES+AGING in WBSF reduction and desirable tenderness ratings than other postmortem treatments (P < 0.05) by reaching a greater proportion (72%) of “tender” (WBSF < 40.1 N) steaks than AGING (48%), ES (36%), and NOES-NOAGING (24%) samples (P < 0.01). Tenderness of bullock loin steaks is marginally improved by crossbreeding; therefore, the application of ES+AGING is necessary to ensure a higher proportion of tenderloin steaks.Se evaluaron los efectos de cruzamientos interraciales y tecnologías postmortem sobre la calidad gustativa de lomos de toros terminados a pasto.  Cincuenta toros añosos representando cinco tipos raciales (n = 10 cada uno): Brahman puro (BRAH), F1-Angus (F1ANG), F1-Chianina (F1CHI), F1-Romosinuano (F1ROM) y F1-Simmental (F1SIM) se suplementaron a pastoreo hasta alcanzar una conformación satisfactoria a un peso vivo de ca. 480 kg. Todas las canales clasificaron como “Bullocks” (Toretes) por la norma estadounidense. Los lados derechos de cada canal se sometieron a estimulación eléctrica de alto voltaje (ES) mientras que los lados izquierdos no fueron estimulados (NOES).  Bistés de longissimus lumborum ES y NOES se asignaron a tratamientos de maduración al vacío por 2 d (NOMADURADOS) ó 10 d (MADURADOS). Los bistés se evaluaron para fuerza de corte Warner-Bratzler (FCWB) y rasgos sensoriales calificados por panelistas capacitados. No se detectaron diferencias en valores FCWB, o calificaciones para jugosidad o intensidad de sabor entre tipos raciales (P > 0.05).  Los rasgos relacionados con terneza variaron poco con el tipo racial (P < 0.05). Los bistecs de F1ANG recibieron calificaciones más altas para terneza de fibra muscular, terneza general y cantidad de tejido conectivo, y difirieron (P < 0.05) de los F1ROM y F1SIM, que recibieron las calificaciones más bajas. Los bistés ES+MADURADOS tuvieron menor FCWB y mayores calificaciones para rasgos asociados con la terneza que los ES ó los MADURADOS (P < 0.05) alcanzando una mayor proporción (72%) de "bistés tiernos" (FCWB < 40.1 N) que la de MADURADOS (48%), ES (36%) y NOES-NOMADURADOS (24%) (P < 0.01). La mejora en terneza de lomos de toretes Brahman mediante cruzamiento con razas taurinas es marginal; por lo tanto, se requiere aplicar el tratamiento combinado de ES y maduración al vacío para asegurar una proporción mayor de bistés tiernos.Foram avaliados os efeitos de cruzamentos interraciais e tecnologias postmortem na qualidade do sabor de lombos de touros terminados a pasto. Cinquenta touros envelhecidos representando cinco tipos de raça (n = 10 cada): Brahman puro (BRAH), F1-Angus (F1ANG), F1-Chianina (F1CHI), F1-Romosinuano (F1ROM) e F1-Simmental (F1SIM) foram suplementados. pastado com uma conformação satisfatória com um peso vivo de ca. 480kg Toda as carcaças classificadas como “Boi” (Toretes) pela norma americana. Os lados direitos de cada canal foram submetidos à estimulação elétrica de alta voltagem (ES), enquanto os lados esquerdos não foram estimulados (NOES). Bifes ES e NOES longissimus lumborum foram submetidos a tratamentos de maturação a vácuo por 2 d (NOMATURED) ou 10 d (MATURED). Os bifes foram avaliados quanto à resistência ao cisalhamento Warner-Bratzler (FCWB) e características sensoriais avaliadas por provadores treinados. Não foram detectadas diferenças nos valores de FCWB, ou classificações de suculência ou intensidade de sabor entre os tipos de raça (P > 0,05). As características relacionadas à ternura variaram pouco com o tipo de raça (P < 0,05). Os bifes F1ANG receberam pontuações mais altas para maciez da fibra muscular, maciez geral e quantidade de tecido conjuntivo, e diferiram (P <0,05) do F1ROM e F1SIM, que receberam as pontuações mais baixas. Os bifes ES + MADUROS apresentaram menor FCWB e maiores classificações para características associadas à maciez do que os bifes ES ou MATURADOS (P < 0,05), atingindo uma proporção maior (72%) de "bifes macios" (FCWB < 40,1 N) do que os bifes MATURADOS (48 %), ES (36%) e NOES-NOMATURADO (24%) (P < 0,01). A melhora na maciez dos lombos de touros Brahman pelo cruzamento com raças tauromáquicas é marginal; portanto, o tratamento combinado de ES e envelhecimento a vácuo é necessário para garantir uma maior proporção de bifes macios

Variations of early postmortem pH in carcasses of grass-fed steers and its relationship with glycolytic potential and meat quality traits

This study aimed to investigate the multivariate relationship between the glycolytic potential, and meat quality traits from grass-fed steers carcasses with variations in early postmortem pH. From a contemporary group of steers (n=70) from the same production unit and slaughtered under similar conditions, thirty carcasses (10/group) were selected based on pH values measured at 3h (pH3h): Low ( 6.5). Carcasses segregated by pH3h groups were different (p 0.05) among pH3h groups. Color variables had a positive and moderate correlation with MGC, G+G6P, LC, and GP. Results does not allow to recommend early carcass segregation by very early pH (3h postmortem); however, important bivariate and multivariate relationships between G+G6P, lactate content and instrumental color parameters in LL muscle from grass-fed cattle were demonstrated

Predicción del rendimiento en cortes, hueso y grasa en búfalos de agua en Venezuela

The objectives of this study were to determine the association between carcass traits and the percentage yield in boneless cuts (PDC), bone, and fat trimmings of water buffalves; and to develop predicted equations for these variables. Forty-eight crossbred Murrah-Mediterránea buffaloes (24 steers and 24 bulls) were used slaughtered at 17, 19 and 24 months. Carcass and retail-yield-cut traits were evaluated. The following analyses were made: descriptive test, correlation, residual and multiple lineal regression. In castrated animals, subcutaneous fat and circumference round explained the majority of the variation in PDC. The dorsal fat thickness and the renal fat were the variables mostly associated with bone yield. In bulls, the subcutaneous fat and the carcass length explained most of the variation of PDC. The fat trimmings showed the highest correlation coefficient with the subcutaneous fat, and the bone yield was most correlated with the conformation. The equations obtained explained more than 50% of the variation in PCD, however equations for bone yield and fat trimmings showed a higher R2.The objectives of this study were to determine the association between carcass traits and the percentage yield in boneless cuts (PDC), bone, and fat trimmings of water buffalves; and to develop predicted equations for these variables. Forty-eight crossbred Murrah-Mediterránea buffaloes (24 steers and 24 bulls) were used slaughtered at 17, 19 and 24 months. Carcass and retail-yield-cut traits were evaluated. The following analyses were made: descriptive test, correlation, residual and multiple lineal regression. In castrated animals, subcutaneous fat and circumference round explained the majority of the variation in PDC. The dorsal fat thickness and the renal fat were the variables mostly associated with bone yield. In bulls, the subcutaneous fat and the carcass length explained most of the variation of PDC. The fat trimmings showed the highest correlation coefficient with the subcutaneous fat, and the bone yield was most correlated with the conformation. The equations obtained explained more than 50% of the variation in PCD, however equations for bone yield and fat trimmings showed a higher R2.Los objetivos de este estudio fueron determinar la asociación entre rasgos de la canal y el rendimiento en cortes (RCD), rendimiento en hueso y recortes de grasa en búfalos de agua, y desarrollar ecuaciones predictivas para cada variable mencionada. Se utilizaron 48 búfalos de agua (24 castrados y 24 enteros), sacrificados a los 17, 19 y 24 meses de edad con mestizaje de razas Murrah y Mediterránea. Se evaluaron las variables de la canal y del rendimiento en cortes. Se realizaron: pruebas descriptivas, análisis de correlación, residuos y de regresión lineal múltiple. En los castrados, el acabado de grasa y la circunferencia del muslo explicaron la mayor variación en RCD. El espesor de grasa y el porcentaje de grasa renal fueron las variables mayormente asociadas con el rendimiento en hueso. En los enteros, el acabado de grasa y la longitud de la canal explicaron la mayor variación en RCD. El recorte de grasa se asoció más con acabado de grasa, y el rendimiento en hueso se asoció con la conformación. Las ecuaciones obtenidas lograron explicar más del 50% de la variación del RCD. Las ecuaciones para recorte de grasa y rendimiento en hueso tuvieron mayor fuerza predictiva

Preliminary observations on carcass traits and meat yield of five types of Brahman-influenced grass-fed bulls

Benefiting from interventions of the savanna ecosystem, breeders in Los Llanos of Apure State (Venezuela) are exploring the opportunity to improve cattle genetics by implementing crossbreeding programs.  Fifty yearling bulls of five types of Brahman influence [ST-Brahman (n = 10), F1 Angus x Brahman (F1-Angus; n = 10), F1 Chianina x Brahman (F1-Chianina; n = 10), F1 Romosinuano x Brahman (F1-Romosinuano; n = 10), and F1 Simmental x Brahman (F1-Simmental; n = 10)] were selected to be compared in carcass performance (linear measurements, quality and quantity indicators, Venezuelan and U.S. grades, and cutability) at a desirable conformation endpoint with a suitable market weight of 480 kg.  Shorter ST-Brahman carcasses exhibited the most abundant finish, significantly different from the longer F1-Simmental and F1-Romosinuano counterparts.  All carcasses fell into the A youngest maturity and were eligible for the USDA "Bullock “class designation; 62% reached the top Venezuelan quality grade, 96% graded US Standard and 64% reached the US yield grade 1, indicating superior cutability. Significant differences in yield of individual cuts (ribeye + strip loin, and cuts from the round) were detected between F1-Romosinuano and St-Brahman, F1-Angus and F1-Chianina counterparts.  F1-Chianina bulls had slight but significant advantages in yield of high-valued boneless cuts as compared to those of F1-Romosinuano and F1-Simmental counterparts. Conversely, F1-Romosinuano outperformed F1-Chianina in 1.73 percentage points of medium-valued boneless cuts (P < 0.05).  Under the sample selection criteria and harvest endpoint, slight changes in carcass performance can be expected from crossbreeding.Con intervenciones del ecosistema sabana y aplicando un manejo adecuado de los pastos, ganaderos de Los Llanos del Estado Apure (Venezuela) estan explorando mejorar la genética del ganado con programas de cruzamiento.  Cincuenta machos enteros añosos de cinco tipos raciales con influencia Brahman [Brahman puro (n = 10), F1 Angus x Brahman (F1-Angus; n = 10), F1 Chianina x Brahman (F1-Chianina; n = 10), F1 Romosinuano x Brahman (F1-Romosinuano; n = 10) y F1 Simmental x Brahman (F1-Simmental; n = 10)] se compararon en desempeño de la canal (mediciones lineales, indicadores de calidad y cantidad, categorías de clasificación y rendimiento carnicero) a un punto final de conformación deseable con un peso corporal aproximado de 480 kg.  Canales más cortas de Brahman puros exhibieron acabado más abundante, diferente (P<0.05) de las contrapartes más largas F1-Simmental y F1-Romosinuano.  Todas las canales cayeron en la madurez más joven (A) y fueron elegibles para la designación de clase "Bullock" del USDA; el 62% alcanzó el grado de calidad superior venezolano (categoría A), el 96% calificó en el grado de calidad Standard y el 64% alcanzó el grado máximo de rendimiento carnicero (grado 1 USDA).  Los toretes F1-Chianina tuvieron ventajas leves pero significativas en rendimiento en cortes deshuesados de alto valor, en comparación con los de F1-Romosinuano y F1-Simmental.  Por el contrario, F1-Romosinuano superó a F1-Chianina en 1,73 puntos porcentuales de cortes deshuesados de valor medio (P <0.05).  Bajo los criterios de selección de la muestra y el punto final de la cosecha, no se pueden esperar grandes cambios en el rendimiento carnicero a partir del cruzamiento.Com o uso de tecnologias em um ecossistema de savana e aplicando um manejo adequado das pastagens, os criadores de Los Llanos do Estado de Apure (Venezuela) estão tentando melhorar a genética do gado através da utilização de programas de cruzamento.  Cinquenta bovinos machos não castrados, com peso de abate de ~480 kg, de cinco cruzamentos com Brahman [Brahman puro (n = 10), F1 Angus x Brahman (F1-Angus; n = 10), F1 Chianina x Brahman (F1-Chianina; n = 10), F1 Romosinuano x Brahman (F1-Romosinuano; n = 10) e F1 Simental x Brahman (F1-Simental; n = 10)], foram comparados quanto às características (medidas lineares, indicadores de qualidade e quantidade e rendimento de desossa) y tipificacao de carcaça.    Carcaças de Brahman puros apresentaram maior cobertura de gordura do que carcaças de animais F1-Simmental e F1-Romosinuano (P<0.05).  Todas as carcaças foram com maturidade “A” (jovem / Bullock), sendo que 96% se qualificaram no grau de qualidade USDA “Standard” e 64% alcançaram o grau máximo de rendimento de desossa (grau 1).  Pelo padrão venezuelano, 62% das carcaças alcançaram o grau de qualidade superior (categoria A).  Diferenças significativas foram detectadas no rendimento de cortes individuais (filé de costela e contrafilé e cortes do coxão) entre carcaças de F1-Romosinuano e F1-Simental e F1-Angus e F1-Chianina. Carcaças de F1-Chianina apresentaram maiores rendimentos em cortes desossados de alto valor em comparação com F1-Romosinuano e F1-Simmental.  Carcaças de F1-Romosinuano tiveram 1,73 pontos percentuais a mais de rendimento em cortes desossados de valor intermediário, que carcaças de F1-Chianina (P <0,05). Segundo os critérios de seleção da amostra e o ponto final de abate, não se podem esperar grandes mudanças na qualidade e rendimento das carcaças de diferentes cruzamentos. &nbsp

Evaluation of Digestible lysine levels in diets with high energy density for finishing pigs

ABSTRACT Objective. To evaluate the effects of different levels of digestible lysine in diets with high energy density on productive performance and carcass characteristics of finishing pigs. Materials and Methods. Seventy crossbred barrows (initial body weight of 83.36 kg) were used and allotted in a randomized block design with five treatments, seven replications and two pigs per experimental unit. Pigs were fed ad libitum with diets containing 3.5 kcal/kg of ME and five levels of digestible lysine (0.46, 0.52, 0.58, 0.64 and 0.70%) during four weeks. Final live weight (FLW), daily feed intake (DFI), daily weight gain (DWG), feed conversion (FC), daily lysine intake (DLI), and the amount of lysine per body weight gain (DLI/DWG), were evaluated. At the end of the experiment, blood samples were taken from each pig to determine urea nitrogen concentration (UN) in serum and slaughtered to evaluate quantitative and qualitative carcass characteristics. Results. The FLW increased linearly (p<0.05).There were no differences among treatments for DFI, DWG, FC, carcass characteristics and UN. The DLI and DLI/DWG varied significantly (p<0.001) and increased linearly (p<0.001) with each lysine level. Pigs that consumed the limiting diet in lysine (0.46%) showed less DLI and DLI/DWG (p<0.001) than pigs fed the other diets. Conclusions. The amount of DLI/DWG increased with the evaluated levels of digestible lysine in diets with high energy density, without effects on productive performance and carcass characteristics of finishing pigs.   RESUMEN Objetivo. Evaluar los efectos de diferentes niveles de lisina digestible en dietas con alta densidad energética sobre el desempeño productivo y características de la canal de cerdos en finalización. Materiales y métodos. Se utilizaron 70 cerdos (peso inicial de 83.36 kg) mestizos castrados, distribuidos en un diseño de bloques al azar con cinco tratamientos, siete repeticiones y dos cerdos por unidad experimental. Los cerdos fueron alimentados ad libitum con dietas que contenían 3.5 Mcal/kg de energía metabolizable y cinco niveles de lisina digestible (0.46, 0.52, 0.58, 0.64 y 0.70%) durante cuatro semanas. Se evaluaron: peso vivo final (PVF), consumo diario de alimento (CDA), ganancia diaria de peso (GDP), conversión de alimento (CA), consumo diario de lisina (CDLis) y la cantidad de lisina por peso ganado (CDLis/GDP). Al final de experimento, se extrajeron muestras de sangre de todos los cerdos para determinar la concentración de nitrógeno ureico (NU) en suero sanguíneo y luego se sacrificaron para evaluar las características cualitativas y cuantitativas de la canal. Resultados. No se observaron diferencias significativas entre tratamientos para CDA, GDP, CA, características de la canal y NU. El PVF incrementó linealmente (p<0.05). El CDLis y la CDLis/GDP variaron significativamente (p<0.001) e incrementaron linealmente (p<0.001) con cada nivel de lisina. Los cerdos que consumieron la dieta limitante en lisina (0.46%) mostraron menor consumo y CDLis/GDP (p<0.001) que los cerdos alimentados con las otras dietas. Conclusiones. Los niveles de lisina digestible evaluados en dietas con alta densidad energética aumentan la CDLis/GDP, sin efectos sobre el desempeño productivo y las características de la canal de los cerdos en finalización