Beef of Nellore cattle has limited tenderization despite pH decline in Longissimus lumborum

Bos taurus indicus temperament is variable and affects beef tenderization. Our objective was to investigate temperament and performance of non­castrated Nellore and identify groups based on Longissimus lumborum (LL) pH decline as well as beef characteristics produced by those groups. We investigated 94 animals with a subset of carcasses (n = 24) selected based on LL pH at 24 h postmortem (pm) to represent two groups: resistant to pH decline (> 5.8 called pH­Res; n = 10) and normal (< 5.7 called pH­Nor; n = 14). Steaks were fabricated from the LL muscle and randomly assigned to aging (2, 7, 14, and 21 days). Sarcomere length, cooking loss, myofibrillar fragmentation index (MFI), and Warner­Bratzler shear force (WBSF) were determined. Data on temperament were investigated in a multivariate approach, while beef data were compared between groups using the analysis of variance. Rectal temperature at the beginning of the finishing phase and total weight gain were greater and related to animals in the pH­Res group (p < 0.01 and p = 0.03, respectively). Temperature and pH decline curves, sarcomere length, and cooking loss revealed that pH­Res produced beef with lower quality compared to the pH­Nor group. Results for MFI and WBSF did not show differences between groups within each time pm; however, overall steaks from pH­Res were tougher (p = 0.06). Incidence of LL pH between 5.8 and 5.9 at 24 h pm did not compromise the tenderization rate or extension; however, it affected the water holding capacity in this population of Nellore cattle.(AU)

Expression of calpain system transcripts responds inversely to beef tenderization after vitamin D3 supplementation in Nellore cattle / Expressão de transcritos do sistema calpaína responde de forma inversa ao amaciamento após suplementação com vitamina D3 em bovinos Nelore

Uma vez que o sistema calpaína é central para o amaciamento da carne e dada a importância da atividade de calpastatina na determinação da maciez de bifes de bovinos Bos taurus indicus, o objetivo do presente estudo foi determinar se a expressão do gene de µ-calpaína (CAPN1), calpastatina total (CAST T), e suas variantes (CAST I e II) foi induzido pela inclusão de vitamina D3 na dieta. Os animais receberam nenhuma ou 2 × 106 UI dose de vitamina D3 por 2 ou 8 dias antes do abate, e foram submetidos a diferentes condições durante o confinamento: exposição solar ou sombreamento artificial. Bifes do Longissimus lumborum foram fabricados e submetidos a maturação por 1, 7, e 21 dias post-mortem e posteriormente usados para determinação da força de cisalhamento e do índice de fragmentação miofibrilar. Vitamina D3 não influenciou a abundância de RNAm, exceto para maior abundância de transcritos de CAST II em animais que foram suplementados por 8 dias antes do abate. Foi encontrada associação negativa entre a abundância de CAST II e a força de cisalhamento. Essa contradição revela uma importante modulação da expressão do sistema calpaína resultado da suplementação com vitamina D que pode ser importante na determinação de estratégias para melhorar a maciez da carne.(AU)

The calpain system is the central player for meat tenderization and the calpastatin activity plays an important role in beef tenderness of Bos taurus indicus cattle. This study investigated whether dietary vitamin D3 induced gene expression of µ-calpain (CAPN1), total calpastatin (CAST T), and their variants (CAST I and II). Animals received none or 2 × 106 IU of vitamin D3 for either 2 or 8 days before slaughter and were submitted to different conditions during feedlot: sun exposure or artificial shade. Steaks from Longissimus lumborum were fabricated, aged for 1, 7, and 21 days post-mortem, and later used for the analyses of shear force and the myofibrillar fragmentation index. Vitamin D3 did not influence mRNA abundance; however, it induced a greater CAST II transcript in animals supplemented 8 days before slaughter. There was a negative association between CAST II abundance and the shear force, which revealed an important modulation of the calpain system expression due to vitamin D supplementation. This result is an important tool for strategies to improve beef tenderness.(AU)

Toughness in Santa Inês lamb meat has negative impact on consumer evaluation / Dureza na carne de cordeiros Santa Inês tem impacto negativo na avaliação do consumidor

Meat tenderness is a major attribute for consumers worldwide. However, few studies investigate the importance of lamb meat tenderness for Brazilian consumers. This study assessed consumers evaluation of lamb meat with high shear forces. Eight lambs were slaughtered at 32.5±2.5kg of live weight and 5 to 6 months of age. The Longissimus dorsi muscle from both half carcasses was randomly assigned to four different postmortem processes: Tough Meat (TM), obtained by cold shortening, Fresh Meat (FM), Aging for 3 (A3) and 7 (A7) days postmortem . The variables measured were the sarcomere length, shear force (WBSF) and myofibrillar fragmentation index. We also applied the sensory analysis using affective acceptance tests with hedonic scale of nine points to measure texture, juiciness and overall quality of the meat. The postmortem processing for TM resulted in shorter sarcomere and greater shear values (p <0.05) compared to all other samples, while FM, A3 and A7, did not differ between the samples. Myofibrillar fragmentation was greater for A7 compared to TM (p <0.05), while FM and A3 showed intermediate values that did not differ between the treatments. In the sensory analysis, TM samples received significantly lower scores (p <0.01) for all attributes compared to other treatments and the attributes were not different between the post rigor processes. Consumers identified and evaluated negatively the meat samples with high WBSF. However, further studies are needed to elucidate the impact of smaller differences in WBSF, at intermediate values, on consumers evaluation.(AU)

A maciez da carne é um atributo importante para os consumidores do mundo todo. Porém, ainda faltam estudos sobre sua importância na área de carne de cordeiro para consumidores brasileiros. O objetivo do estudo foi verificar a avaliação dos consumidores em relação à carne de cordeiro com força de cisalhamento elevada. Oito cordeiros foram abatidos com 32,5 ± 2,5kg de peso vivo e 5 a 6 meses de idade. O músculo Longissimus dorsi das meias carcaças foi distribuído aleatoriamente em quatro diferentes processamentos postmortem: Carne Endurecida (CE), obtido pelo encurtamento pelo frio, Carne Fresca (CF), maturada por 3 (M3) e 7 (M7) dias postmortem . As variáveis ​​medidas foram comprimento do sarcômero, força de cisalhamento (FC), índice de fragmentação miofibrilar (IFM)e testes sensoriais de aceitação afetiva com escala hedônica de nove pontos para textura, suculência e qualidade global. O processamento postmortem para CE resultou em menor sarcômero e maiores valores de FC (p <0,05) em comparação com outras amostras, enquanto estas não diferiram entre si. O IFM foi maior para M7 em relação à CE (p <0,05), enquanto CF e M3 apresentaram valores intermediários que não diferiram. Noteste sensorial, as amostras de CE receberam escores menores (p <0,01) para todos os atributos comparados aos demais tratamentos, que não diferiram entre si. Os consumidores avaliaram negativamente a carne que apresentou alta FC. Porém, estudos devem ser realizados para elucidar o impacto de diferenças menores, em faixas intermediárias de FC, na avaliação do consumidor.(AU)

Toughness in Santa Inês lamb meat has negative impact on consumer evaluation / Dureza na carne de cordeiros Santa Inês tem impacto negativo na avaliação do consumidor

Meat tenderness is a major attribute for consumers worldwide. However, few studies investigate the importance of lamb meat tenderness for Brazilian consumers. This study assessed consumers’ evaluation of lamb meat with high shear forces. Eight lambs were slaughtered at 32.5±2.5kg of live weight and 5 to 6 months of age. The Longissimus dorsi muscle from both half carcasses was randomly assigned to four different postmortem processes: Tough Meat (TM), obtained by cold shortening, Fresh Meat (FM), Aging for 3 (A3) and 7 (A7) days postmortem . The variables measured were the sarcomere length, shear force (WBSF) and myofibrillar fragmentation index. We also applied the sensory analysis using affective acceptance tests with hedonic scale of nine points to measure texture, juiciness and overall quality of the meat. The postmortem processing for TM resulted in shorter sarcomere and greater shear values (p <0.05) compared to all other samples, while FM, A3 and A7, did not differ between the samples. Myofibrillar fragmentation was greater for A7 compared to TM (p <0.05), while FM and A3 showed intermediate values that did not differ between the treatments. In the sensory analysis, TM samples received significantly lower scores (p <0.01) for all attributes compared to other treatments and the attributes were not different between the post rigor processes. Consumers identified and evaluated negatively the meat samples with high WBSF. However, further studies are needed to elucidate the impact of smaller differences in WBSF, at intermediate values, on consumers’ evaluation.

A maciez da carne é um atributo importante para os consumidores do mundo todo. Porém, ainda faltam estudos sobre sua importância na área de carne de cordeiro para consumidores brasileiros. O objetivo do estudo foi verificar a avaliação dos consumidores em relação à carne de cordeiro com força de cisalhamento elevada. Oito cordeiros foram abatidos com 32,5 ± 2,5kg de peso vivo e 5 a 6 meses de idade. O músculo Longissimus dorsi das meias carcaças foi distribuído aleatoriamente em quatro diferentes processamentos postmortem: Carne Endurecida (CE), obtido pelo encurtamento pelo frio, Carne Fresca (CF), maturada por 3 (M3) e 7 (M7) dias postmortem . As variáveis ​​medidas foram comprimento do sarcômero, força de cisalhamento (FC), índice de fragmentação miofibrilar (IFM)e testes sensoriais de aceitação afetiva com escala hedônica de nove pontos para textura, suculência e qualidade global. O processamento postmortem para CE resultou em menor sarcômero e maiores valores de FC (p <0,05) em comparação com outras amostras, enquanto estas não diferiram entre si. O IFM foi maior para M7 em relação à CE (p <0,05), enquanto CF e M3 apresentaram valores intermediários que não diferiram. Noteste sensorial, as amostras de CE receberam escores menores (p <0,01) para todos os atributos comparados aos demais tratamentos, que não diferiram entre si. Os consumidores avaliaram negativamente a carne que apresentou alta FC. Porém, estudos devem ser realizados para elucidar o impacto de diferenças menores, em faixas intermediárias de FC, na avaliação do consumidor.

Pork loin two-toning and drip loss in relation to steak cross-section anatomical position, plasma and exudate glucose

Perception of color and its relationship to water holding capacity are important for defining the yield and quality of the pork production process. The aim of this study was to identify the relationship among color measurements taken at various anatomical positions in the cross-sectional surface of pork loin steak, and measurements of fluid exudation and its glucose concentration, as well as the impact on these attributes due to plasma glucose at slaughter. Two assays were conducted sequentially: i) investigation of the surface color parameters at different anatomical positions in the pork loin cross-section and their relationship to general exudation; and ii) the effect of plasma glucose levels on surface color variables, drip loss and glucose exudate concentration in three anatomical regions in the steak. The L* value of the ventro-lateral region, in the first assay, had the highest correlation with average steak drip loss at all anatomical points, exudation increasing proportionally between 48 and 72 h. The hue angle was also positively correlated with drip loss and lightness. The drip loss was greater when the animals had high plasma glucose, especially in the intermediate and lateral regions of the steak surface. The intermediate region presented greater lightness and lower redness. The plasma and glucose exudate concentrations, potential indicators of the muscle glycolytic metabolism, were related to color and drip loss. These variables can be influenced by the anatomical region inside the muscle, impacting the ability to retain water, two-toning occurrence and overall pork loin quality.

Pork loin two-toning and drip loss in relation to steak cross-section anatomical position, plasma and exudate glucose

Perception of color and its relationship to water holding capacity are important for defining the yield and quality of the pork production process. The aim of this study was to identify the relationship among color measurements taken at various anatomical positions in the cross-sectional surface of pork loin steak, and measurements of fluid exudation and its glucose concentration, as well as the impact on these attributes due to plasma glucose at slaughter. Two assays were conducted sequentially: i) investigation of the surface color parameters at different anatomical positions in the pork loin cross-section and their relationship to general exudation; and ii) the effect of plasma glucose levels on surface color variables, drip loss and glucose exudate concentration in three anatomical regions in the steak. The L* value of the ventro-lateral region, in the first assay, had the highest correlation with average steak drip loss at all anatomical points, exudation increasing proportionally between 48 and 72 h. The hue angle was also positively correlated with drip loss and lightness. The drip loss was greater when the animals had high plasma glucose, especially in the intermediate and lateral regions of the steak surface. The intermediate region presented greater lightness and lower redness. The plasma and glucose exudate concentrations, potential indicators of the muscle glycolytic metabolism, were related to color and drip loss. These variables can be influenced by the anatomical region inside the muscle, impacting the ability to retain water, two-toning occurrence and overall pork loin quality.(AU)