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The objective of this study was to investigate the influence of meat temperature on moisture loss, muscle water properties, and protein profiles in broiler pectoralis major with the severe woody breast (WB) condition. Broiler breast samples were collected from a commercial plant and sorted into normal, WB, and pale, soft, and exudative (PSE). Temperature treatments included 23°C, 40°C, 53°C, 57°C, 68°C, and 90°C based on denaturation of major muscle protein types during heating. Moisture loss was estimated with weight changes, water properties were measured with time-domain nuclear magnetic resonance measurements, and protein profiles were determined with SDS electrophoresis gel. There were no differences in moisture loss between 3 groups at meat temperature 23°C, 40°C, and 57°C. Moisture loss of WB samples was greater than normal and PSE at either 68°C or 90°C; however, it was the least at 53°C. Only close changing trend was noted between the intramyofibrillar water (T21) reduction and moisture loss. The extramyofibrillar (T22) water content and reduction in WB meat during heating were consistent greater, and electrophoretic profiles differed among 3 muscle conditions. Data suggest that greater reductions in intramyofibrillar and extramyofibrillar water are responsible for the increased moisture loss in WB meat at higher temperature.

The objective of this study was to evaluate different methods used for estimating cook loss in broiler breast fillets (pectoralis major). Two experiments were conducted. In the first experiment, intact fillets were weighed, cooked to 75°C, and then subjected to 1 of 3 postcook handling treatments: cooling for 5 min at room temperature before reweighing (5-minute), cooling at room temperature until they reached room temperature before reweighing (RT), or cooling in ice water until they reached room temperature before reweighing (IW). In the second experiment, breast fillet portions were used to compare the effects of endpoint temperature (53°C, 57°C, 68°C, 75°C, or 90°C) on cook loss estimation by the 5-minute and RT methods. Breast fillets were collected from local chicken processing plants and trimmed to similar weight prior to cooking. Cook loss, cook loss retention, and total cook loss after 24 h in cooked fillets were measured for comparisons. Data showed that cook loss (<17%) and total loss (19.3%) estimated with the IW method were lower (P < 0.05) than those with the 5-minute and RT methods (19–21% for cook loss and 21.1–21.3% for total loss), which did not differ from each other. When the endpoint temperature was ≥75°C, no differences in cook loss estimates or moisture loss were noted between the 5 min and RT methods (after 3 h cooling). However, when the temperatures were 53°C to 75°C, cook loss estimations were significantly different (P < 0.05) between the 5 min and RT methods (more than 4%). Reduced endpoint temperature resulted in increasing differences (from less than 5% to more than 9%) in cook loss estimates. These results demonstrate that endpoint cooking temperature and postcooking sample handling methods may affect cook loss estimates in broiler breast meat.

The purpose of this study was to investigate the relationships between muscle water properties, water-holding capacity (WHC), and woody breast (WB) severity in intact raw broiler breast fillets. Broiler pectoralis major deboned at 3 h postmortem was collected from a commercial plant and categorized as normal (NORM), moderate WB, or severe WB (SEV). Meat drip loss was calculated based on weight loss during overnight storage at 4°C. Water properties of the intact fillets were determined with time domain nuclear magnetic resonance and the T2relaxation times were determined using an inverse Laplace algorithm (CONTIN). Three T2water components, hydration water (T2b), intra-myofibrillar water (T21), and extra-myofibrillar water (T22), were identified. With increasing WB severity, the time constant of each water component and the relative content of T22(P22) increased while the relative areas of T2band T21(P2band P21, respectively) decreased. Spearman correlation analysis showed that there were significant correlations between the WB condition score and either the time constant or normalized area for each T2component. T22normalized areas (A22) were most strongly correlated with the WB score (r = 0.75); however, the weakest correlation was found between the WB score and T21areas (A21). Pearson correlation analysis revealed that the strongest correlation (r = 0.64) was found between A22and drip loss; however, there was no correlation between A21and drip loss. Within the NORM group, drip loss was significantly correlated to the time constants for both T2band T21. Within the SEV group, only A22was significantly correlated to drip loss. These data indicate that the WB condition has a significant impact on the distribution of water within the intact muscle tissue. The content of extra-myofibrillar water in broiler breast fillets may be a key factor responsible for the poor WHC measurements in WB meat.

The objective of this study was to compare the relationships between instrumental texture measurements and subjective woody breast (WB) scores in raw broiler breast fillets. A total of 181 broiler breast fillets were scored based on palpable hardness and rigidity ranging from 1.0 to 3.0 in 0.5 increments. Texture properties of raw fillets were measured with 3 different instrumental methods: compression force, blunt Meullenet-Owens Razor Shear (BMORS), and Meullenet-Owens Razor Shear (MORS). Compression force was measured based on % of fillet height (30%) and distance (10 mm). Blunt Meullenet-Owens Razor Shear and MORS measurements included peak force, energy, and peak counts. One-way ANOVA of instrumental texture measurements were performed. Spearman correlations between WB scores and instrumental texture measurements and Pearson correlations between 3 instrumental measurements were analyzed. ANOVA results showed that the best means separations between WB scores were found with the compression method. The weakest means separations were observed with MORS force and BMORS peak counts. Spearman correlation coefficients showed that there were significant relationships between WB scores and instrumental measurements. The strongest correlations were found between subjective WB scores and compression force measurements (r = 0.58–0.73, P < 0.0001), followed by BMORS force and energy (r = 0.55–0.56, P < 0 0.0001), MORS energy and peak count (r = 0.47–0.50, P < 0 0.0001), and BMORS peak count (r = −0.18, P = 0.015). The weakest correlation was found between the WB scores and MORS force (r = 0.17, P = 0.023). Pearson correlation coefficients between 3 different instrumental texture methods were also significant (P < 0.0001). These results demonstrate that there are significant correlations between subjective WB scores and instrumental texture measurements but that correlation strength varies with the instrumental method. Instrumental texture measurements can be used as references for subjective WB scores. Compression force method has the best potential for assessing subjective WB condition scores.

The relationship between woody breast (WB) and white striping (WS) myopathies were investigated in breast fillets collected from commercial slaughter facilities that process large broilers. For the population of samples collected in this study, 94.2% of all WB fillets also exhibited WS. Of the fillets that did not exhibit WB, 54.0% exhibited WS. Of the fillets that exhibited severe WB, 27.9% had severe WS, 50.9% had moderate WS, and 21.2% had mild or no WS. Approximately 82.8% of all WS fillets also exhibited WB. Of the fillets that did not exhibit WS, 26.0% exhibited WB. Among fillets that exhibited severe WS, 40.7% had severe WB, 46.0% had moderate WB, and 13.3% had mild or no WB. The strength of the relationship between WS and WB scores decreased as average fillet weight increased. In addition to overall WB and WS scores, a subset of fillets was also evaluated for specific attributes of muscle hardness, rigidity, out-bulging shape, and the occurrence of petechial hemorrhages on the skin-side surface of the fillets. Muscle hardness, rigidity, and out-bulging shape were highly correlated to WB scores but their relationships with WS were much weaker. There was a statistically positive, but relatively weak, correlation between the occurrence of petechial hemorrhages and the WB and WS myopathies. With regards to developing WB sorting criteria and methodologies, tactile traits have a greater potential for accurately indicating the presence and severity of the WB myopathy in broiler breast meat than visually-assessed traits such as WS.

This paper focuses on “alternative methods for initial broiler processing” and exploration of alternative processing including slaughter at the farm immediately after catching. On-farm slaughter and transport (FSaT) is envisioned as a mobile unit that stuns, slaughters, and shackles the broiler carcasses at the farm. A separate trailer-unit then transports the shackled broiler carcasses to the processing plant. Once at the processing plant carcasses are mechanically transferred into plant shackle lines and moved into processing. The hypothesis is that the FSaT approach will dramatically improve overall bird welfare and well-being by reducing live handling and eliminating live transport from the farm to the processing plant. In addition, ancillary impacts could include: improving yield efficiencies by eliminating dead on arrivals, potentially reducing water and energy consumption, reducing labor requirements at the processing plant with the elimination of live rehang, and offering an economically sustainable alternative. The FSaT approach represents a radical change from traditional processing, and its effects on poultry processing need to be evaluated. This paper presents results of experiments conducted at a commercial poultry processor to evaluate feather picking efficiency, carcass bacteriological loading, and meat quality for delayed processed carcasses.

Vacuum-tumbling marination is often used to improve the yield and quality of whole or portioned broiler breast fillets. The relationship between the marination performance of whole Pectoralis majormuscles and breast fillet sub-samples is not well understood. The objective was to determine the effects of sub-sampling and freezing-thawing on the marination performance and cook loss of broiler breast meat. Paired right and left breast fillets were marinated as whole fillets or sub-samples (cranial and mid-caudal portions). Samples were marinated at 48 h postmortem (fresh) or stored at −20°C and then thawed prior to marination (frozen-thawed). Samples were vacuum-tumbled in 20% wt/wt brine (5% NaCl, 3% STP) and weighed pre-marination, during marination (15, 30, and 45 min), and 24 h post-marination. Samples were then cooked to 75°C for determination of cook loss. Marinade uptake was greater in caudal sub-samples than intact fillets and cranial sub-samples after 15 min of marination (P< 0.0001). After 30 min, marinade uptake was greater in caudal sub-samples and intact fillets than cranial sub-samples (P< 0.05). After 45 min, marinade uptake for fresh samples was greatest in intact fillets and lowest in cranial sub-samples. For frozen-thawed samples, marinade uptake at 45 min was greater in caudal sub-samples and intact fillets than cranial sub-samples (P< 0.0001). Marinade uptake in sub-samples at 30 min was greater in frozen-thawed versus fresh fillets (P< 0.05). Differences in marinade retention were not observed. Cook loss was similar between fresh and frozen-thawed samples but was greater in sub-samples compared to intact fillets (P< 0.0001). Correlations between marinade uptake in intact fillets and cranial sub-samples were greater in fresh (r = 0.64 to 0.78) than frozen-thawed samples (r = 0.39 to 0.59). Correlations between marinade uptake in intact fillets and caudal sub-samples were greater in frozen-thawed (r = 0.79 to 0.82) than fresh samples (r = 0.46 to 0.63). Data suggest that the relationships between marination performance of whole breast fillets and fillet sub-samples are dependent upon prior sample handling and intra-fillet sampling location.

The woody breast (WB) condition negatively influences the texture characteristics and quality of intact broiler breast fillets (Pectoralis major). But the impact of WB on ground meat is unknown. The objective of this study was to evaluate the effects of WB on the texture and cook loss of ground meat made of broiler breast fillets. Broiler breasts (deboned 3 h postmortem) were collected on 3 separate trial d from the commercial deboning line and classified into normal and severe WB fillet categories. Individual fillets were either ground and formed into patties or left intact prior to being stored for 7 d at −20°C. Samples were then cooked directly from the frozen state to an endpoint temperature of 76 °C for cook loss, instrumental (patties: Allo-Kramer shear; fillets: Warner-Bratzler shear), and descriptive sensory analysis of texture. Cook loss was greater (P< 0.05) in intact WB fillets compared to that in intact normal fillets, but there was no difference (P> 0.05) between WB and normal patties. There was no difference (P> 0.05) in shear force between normal and WB samples regardless of meat type. Sensory analysis showed that average scores of springiness and hardness of intact WB fillets were greater than those of normal fillets (P< 0.05). However, there were no significant differences (P> 0.05) in average scores for sensory attributes cohesiveness, hardness, juiciness, fibrous, and rate of breakdown between WB and normal patties. WB patties exhibited lower springiness and chewiness scores (P< 0.05) than normal patties. Data suggest that undesirable differences in sensory texture characteristics between cooked intact WB and normal breast meat can be minimized in a ground product.

Muscle shortening and postmortem proteolysis both influence beef tenderness, but their interacting effects on tenderness are relatively unknown. Inherent myofibril structure and the extent of overlap between myosin and actin filaments are hypothesized to affect the availability of substrates for degradation by calpains. The objective of this study was to determine the influence of sarcomere length on the extent of calpain-induced proteolysis of bovine myofibrils in vitro. Bovine semitendinosus muscles were excised within 20 min postmortem and dissected into strips, which were stretched and attached to applicator sticks or allowed slack to generate samples with different sarcomere lengths upon rigor completion. Samples were allowed to undergo rigor in a neutral pH buffer containing a protease inhibitor. Myofibrils were isolated and incubated at room temperature with excess exogenous μ-calpain at a ratio of 1:800 (wt/wt; enzyme:myofibrillar protein) at pH 6.8 for 0, 2, 60, 1,440, or 2,880 min. Purified troponin was subjected to the same digestion conditions. Proteolysis of troponin T (TnT) was monitored using SDS-PAGE and Western blotting. Sarcomere length was greater (P< 0.0001) in stretched versus shortened samples (2.99 μm ± 0.03 vs. 2.12 ± 0.03 μm, respectively, means ± SE). Western blots for both stretched and shortened samples exhibited bands corresponding to intact TnT and TnT fragments. The abundance of intact TnT decreased (P< 0.0001) with incubation time across both treatments. At 1,440 and 2,880 min, less (P< 0.05) intact TnT was detected in samples with long sarcomeres. These data indicate proteolysis of TnT occurs to a greater extent in samples with longer sarcomeres, possibly due to easier access of proteases to their targeted substrates. Degradation patterns of TnT were qualitatively similar between myofibrils and purified troponin after incubation with μ-calpain. Therefore, it is unlikely that the mechanism by which proteolysis is limited in short sarcomeres involves an actomyosin-mediated interference of TnT.

The interaction between sarcomere length and postmortem proteolysis as related to meat tenderness is not clear. The extent of thick and thin filament overlap alters actomyosin binding and may alter substrate availability during aging-induced tenderization. The objective of this study was to determine the influence of sarcomere length on proteolytic degradation in beef. Strips from bovine semitendinosus were either stretched 40% and restrained or allowed to shorten unrestrained in an ice bath. After rigor completion, 0.6-cm cross sections were fabricated and were randomly assigned to 2, 4, 7, or 10 d of aging treatments. Myofibrils were isolated for sarcomere length determination. Samples were collected and frozen for shear force analysis, and muscle proteins were extracted for SDS-PAGE and Western blotting analyses to determine troponin T (TnT) proteolysis. Sarcomere length was greater (P< 0.01) in stretched muscle samples compared with shortened samples (2.57 vs. 1.43 μm, respectively). Correspondingly, shear force values were greater (P< 0.05) in shortened samples than stretched samples. Western blots revealed the presence of 3 major intact TnT bands that diminished with time postmortem and 4 bands (TnT degradation products) that accumulated during postmortem storage. Quantification of intact TnT showed increased (P< 0.05) proteolysis at 4 and 7 d postmortem in samples with long sarcomeres. By 10 d, only traces of the greatest molecular weight intact TnT band were evident in both shortened and stretched samples, suggesting this TnT band may be more susceptible to proteolysis than other intact TnT bands. Degradation products of TnT appeared earlier postmortem in samples with long sarcomeres. The 30-kDa TnT fragment appeared after 7 d of postmortem storage in samples with long sarcomeres but not until 10 d in muscle containing short sarcomeres. Collectively, these data show that postmortem TnT proteolysis is sarcomere length-dependent and suggest that thick and thin filament overlap may influence the postmortem aging process in beef.

Pale, soft, and exudative (PSE) pork is primarily caused by an accelerated rate of postmortem glycolysis resulting in low muscle pH while carcass temperature remains high, thus causing protein denaturation. Numerous factors influence the rate of postmortem metabolism and may be responsible for the rapid pH decline characteristic of PSE pork during the 1st h postmortem. Release of high levels of Ca2+from the sarcoplasmic reticulum into the sarcoplasm triggers an accelerated rate of postmortem glycolysis and is responsible for the high incidence of PSE observed in halothane pigs. Because total muscle ATPase activity is closely associated with rate of glycolysis, differences in myosin ATPase activity may explain in part the accelerated glycolysis in PSE development. Although important in determining the overall rate of glycolysis, differences in glycolytic enzyme activities have failed to explain discrepancies in postmortem metabolism between PSE and normal muscle. Elevated muscle glycogen content and an extended duration of postmortem glycolysis can also result in PSE-like characteristics, as seen in RN-pigs. Shifts in muscle fiber type toward higher proportions of glycolytic fibers may help explain the incidence of PSE. Inherent differences in mATPase activity, Ca2+regulation, glycolytic enzyme profiles, and glycogen content between muscle fiber types integrate various mechanisms responsible for the abnormal postmortem glycolysis in PSE muscle. In an effort to delineate potential mechanisms responsible for PSE, models to artificially induce PSE, such as retarding temperature decline and electrical stimulation, provide useful tools. The value and limitations of these models stem from their abilities to alter postmortem temperature and pH declines and to effectively simulate the protein denaturation typical of PSE pork.

The woody breast (WB) condition is an emerging myopathy found in broiler breast Pectoralis major. It greatly influences the texture characteristics and quality of raw meat. The objective of this study was to evaluate the effects of WB on the sensory quality of cooked intact and ground broiler breast meat. Broiler breast fillets (deboned 3 h postmortem) were collected from a commercial deboning line and classified into normal and severe WB categories based on the prevalence and severity of diffuse hardened areas and overall fillet rigidity. Individual fillets (24 per treatment) were either ground to make patties or left intact prior to being stored for 7 days at -20P > 0.05) in the sensory texture attributes of juiciness, cohesiveness of mass, bolus size, fibrous, or rate of breakdown were observed, classified normal and WB samples. However, the springiness and hardness values of intact WB fillets were greater than those of normal fillets (P < 0.05). Springiness and chewiness values of WB patties were lower (P < 0.05) than those of normal patties. No differences (P > 0.05) in shear force were observed between normal and WB samples for either intact fillets or patties. Results demonstrate that the WB condition negatively influences the sensory texture quality of intact chicken breast fillets. However, the undesirable effects of the WB condition on cooked meat texture can be minimized in a ground product.

The life history and feeding habits of larval Rivellia melliginis (Fitch) are presented. Courtship and mating occur on or near the host plant, black locust, Robinia pseudoacacia L.; eggs are placed in clusters of 10–20 in soil below the host plant; larvae attack and destroy the nitrogen-fixing root nodules, each larva destroying up to 6 nodules; overwintering occurs as a fully grown larva in diapause; and puparia are formed in soil. There are two generations a year in northeastern Ohio. It is suggested that larval feeding affects the nitrogen-fixing capability of black locust, a species widely used in reclamation of stripmined lands.