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

Effects of the inclusion of brown seaweed (Macrocystis pyrifera) additive in the diet of grass-fed steers on carcass performance, meat quality, and nutrient composition

The objective of this study was to evaluate the inclusion of a brown seaweed additive (SWA; Macrocystis pyrifera) in the diet of grass-fed steers on carcass performance, beef quality, and nutrient composition. A total of 20 Holstein-Friesian steers were randomly distributed into two groups: Control group (a basal diet without supplementation of SWA) and SWA group (2%-SWA) with basal diet + 30 g/day/animal of SWA during the breeding phase (11 months) and 48 g/day/animal of SWA during the fattening phase (4 months). Steers fed with 2%-SWA were not different (P>0.05) in final body weight, carcass weight, carcass dressing, fat thickness, ribeye area, and marbling score than those from the Control group. Likewise, no effects of 2%-SWA supplementation were detected (P>0.05) for beef quality traits, glycolytic potential, or their metabolites (muscular glycogen, glycose+glucose-6-phosphate, and lactate), evaluated in longissimus lumborum (LL) samples. Sensory evaluation showed a slight preference for Control group samples rather than those from the 2%-SWA group (58.93% and 41.07%; P=0.06). Regarding, proximal composition, the inclusion of SWA only affected the total lipids present in the LL samples, which decreased significantly (P=0.01) in LL samples of grass-fed steers fed with 2%-SWA. The composition of macro (Ca, Na, Mg, P, and K) and micro (Mn, Fe, Cu, and Zn) minerals in LL samples were not affected (P>0.05) by the inclusion of SWA in the diet. The inclusion of the additive based on brown seaweed had not a detrimental effect on carcass performance, beef quality, and mineral content, however, it reduced the total lipids content in the LL muscle

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

Influencia de los métodos combinados de conservación por frío y tipo de envasado sobre la calidad de la carne bovina cruda y cocida

The aim of this study was to evaluate the quality traits of raw (color, weight loss and pH) and cooked meat (cooking loss and shear force) with three combined forms of preservation (refrigerated and freezed), and packing (vacuum packaging, tray with plastic film of polyvinylchloride (PVC), and PVC plastic foil + aluminum). Samples taken from Longissimus thoracis muscles were distributed in the following treatments: T1: control, meat evaluated in the following treatments: T1: control, meat evaluated immediately (48 h postmortem). T2: vacuum packed and refrigerated for 15 days. T3: packaged in tray with plastic film of PVC and frozen for 15 days. T4: wrapped with plastic PVC + aluminum foil and frozen for 15 d. The effect of treatments was significant (P<0.05) for shear force, redness (a value), chroma, and water holding capacity parameters. The T2 samples were tender that the rest and showed less redness and more water holding capacity. Under freezing, T4 resulted in lower cooking losses that T3 samples. The results indicate that cold preservation methods (refrigeration vs. frozen) and type of packaging affects the quality of beef.El propósito de este trabajo fue evaluar las características de calidad de la carne cruda (color, pérdida de peso, y pH) y cocida (pérdidas por cocción y resistencia al corte) tratadas con tres formas combinadas de conservación por frío (refrigeración y congelación) y envasado (al vacío, bandejas + cubierta de policloruro de vinilo (PVC) y envoltorio de PVC+ papel aluminio). Muestras de músculo longissimus thoracis se distribuyeron en los siguientes tratamientos: T1 (control: carne con 48 h postmortem y evaluada inmediatamente); T2 (envasado al vacío y refrigerado por 15 días); T3 (envasado en bandeja con cubierta de PVC y congelado por 15 días) y T4 (envoltorio adherente de PVC + papel aluminio y congelado por 15 días). El efecto del tratamiento resultó significativo (P<0.05) para la resistencia al corte, la intensidad de rojo (valor a), el valor croma, las pérdidas de peso crudo, las pérdidas por evaporación y por escurrimiento. Las carnes T2 resultaron más tiernas con menor intensidad de rojo y menores pérdidas de agua. Bajo congelación, el T4 resultó con menores pérdidas de cocción que el T2. Los resultados indican que la forma de conservación por frío (refrigeración vs congelado) y el tipo de envase afecta la calidad de la carne de re