Concentration of lipids, cholesterol, and fatty acid profile in chicken breast meat affected by wooden breast myopathy frozen for up to 12 mo.

The aim of this study was to examine the effects of frozen storage for 12 mo on the concentrations of lipids and cholesterol and fatty acid profile of wooden chicken breast meat. A total of 120 samples of chicken breasts were selected, according to the degree of "wooden breast" myopathy ["severe," "moderate," and "normal" (absence of myopathy)], from male chickens slaughtered at 42 d of age, from Cobb 500 strain. Part of the samples (n = 20/grade of severity) were evaluated on the day of collection and the remainder were packaged, frozen and stored at -18°C for up to 12 mo. At the beginning (collection day) and at the end of the proposed freezing period (12 mo), analyses of lipid, cholesterol, and fatty acid profile were carried out. Percentage of saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were evaluated. Meats affected by wooden breast myopathy had lower levels of PUFA that exert beneficial effects on health, such as DHA, EPA and ARA, and this profile is impaired by prolonged storage (12 mo), which results in important nutritional losses for the consumer.

Physical, chemical, and microbiological evaluation of sausages produced with chicken meat affected by deep pectoral myopathy.

The purpose of the present study was to characterize the chemical composition, lipid oxidation, and physical characteristics of fresh sausages produced with meat from the pectoralis major muscle affected by deep pectoral myopathy. For the characterization of myopathy, samples were collected from broiler chickens slaughtered between 42- and 46-days old in a slaughterhouse in the state of São Paulo. The experiment consisted of samples from pectoralis major muscle of birds affected or not by DPM (normal-absence of myopathy and DPM category 3-progressive degeneration of the pectoralis minor with a greenish appearance). After classification of the samples, a part of raw products with the pectoralis minor removed, was submitted to microbiological and physical analyses for the characterization of DPM. Afterward, only the pectoralis major muscle was used to manufacture fresh sausages and 2 groups were established. The evaluated parameters were: color, pH, water-holding capacity (WHC), cooking loss (CL), shear force (SF), water activity (Aw), and chemical composition. Meat pH was higher (P < 0.05) in meats with DPM, however, WHC values were lower (71.92%), which made CL value increase (25.31%). In addition, the coloring increased and the technological characteristics of raw breasts were less favorable with the presence of DPM. All fresh sausages' color (except a* higher control group), pH, and Aw values were higher in DPM group. No effect on SF values was observed between fresh sausages. In chemical composition, only protein content increased in fresh sausages with DPM. Microbiological analyses did not indicate bacterial contamination of raw samples and fresh sausages. Data obtained in the present study suggest fresh sausages produced with breasts affected by DPM are a viable alternative and may confer more favorable qualitative characteristics to sausages than the raw marketed meat.

Effect of freezing on the quality of breast meat from broilers affected by wooden breast myopathy.

The objective of the present study was to characterize possible variations in the quality of wooden chicken breast meat during freezing for 12 mo, in order to prove whether the shelf life recommended by the industry allows the storage of that type of meat without compromising its consumption. Three hundred samples of male Cobb 500 broilers slaughtered at 42 d of age were used. Part of the samples (n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree) were analyzed on the day of collection (beginning), previously kept under refrigeration (4°C). The other samples were stored (-18°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), physical and chemical analyses were performed (per period: n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree). Color (L*, a*, and b*), pH, water-holding capacity, cooking losses, tenderness, lipid oxidation, chemical composition, cholesterol concentration, mineral profile, and collagen concentration were evaluated. The physicochemical quality of wooden chicken breast meat is significantly altered during frozen storage for 12 mo, being of inferior quality when compared to normal chicken breast meat, which can negatively affect consumer acceptance. However, it should be noted that even after 12 mo of freezing, the meats did not show oxidative rancidity.

Research Note: Quality parameters of turkey hens breast fillets detected in processing plant with deep pectoral myopathy and white striping anomaly.

The increase in the consumption of poultry meat intensified production, which allowed the emergence of myopathies associated with broiler and turkey meat. The aim to examine possible quality alterations in the 240 Pectoralis major muscle (breast fillets) from carcasses of turkey breeder hens. Regarding DPM, 120 samples of breast fillets from turkey of the Nicholas strain with Pectoralis minor muscle together were selected according to the occurrence of the myopathy in the Pectoralis minor muscle (tender), as follows: DPM score 2 (n = 40), DPM score 3 (n = 40), and a control group unaffected by DPM, score 0 (n = 40). Then, different 120 samples, from the same flock of birds, were selected according to White Striping (WS) anomaly in the Pectoralis major muscle (breast fillets), considering the degree of severity of the striations apparent in the muscle, as follows: moderate (n = 40), severe (n = 40) and a control group (normal) without the presence of WS anomaly (n = 40), with set up as a completely randomized design with 3 treatments for DPM and WS. We evaluated in meat of turkey breeder hens color, water-holding capacity (WHC), cooking loss (CL), shear force (SF), sarcomere length (SL) and total, soluble and insoluble collagen contents. The color parameters lightness (L*), redness (a*), and yellowness (b*) of turkey breeder hens breast fillets were altered by the occurrence of DPM and WS and as except CL, there were a difference for WHC and SF (P < 0.05). Significant differences were observed for sarcomere length (P < 0.05) between fillets without myopathies and with DPM Score 2 and 3 too. Higher values of total collagen (%) were observed for the most severe category of involvement for both myopathies. The DPM and WS affect the color and in a partial reduction texture of the breast fillets meat of turkey breeder hens and this may have a negative economic impact on the meat industry, because these are the main points evaluated by the consumer, in the most value commercial cut.

Physical and chemical characteristics of the longissimus dorsi from swine reared in climate-controlled and uncontrolled environments.

The aim of this study was to evaluate the effect of ambient temperature on the physical and chemical characteristics of the longissimus dorsi muscle by comparing the quality of meat from pigs reared in a controlled and in an uncontrolled environment, the latter provided with a shallow pool. Twenty castrated male pigs of the Topigs line were randomly allotted to two treatments: a controlled environment, with constant temperature (22 °C) and relative humidity (70%); and an uncontrolled environment in a conventional shed for rearing pigs equipped with a shallow pool, where pigs were subject to climatic variations. Meat from pigs kept in the controlled environment showed a greater capacity to retain intracellular water, higher tenderness, and lower cholesterol levels than meat from pigs reared in the uncontrolled environment, but displayed higher lipid oxidation and a lower concentration of DHA. Treatments had no effect on color, pH, chemical composition, or fatty acid profile (except DHA concentration). Rearing pigs in sheds equipped with a shallow pool minimizes the effects of environmental heat on meat quality, allowing the production of high-quality meat in warm climate regions without expensive investments. Animals reared in an uncontrolled environment equipped with a shallow pool are able to produce meat with characteristics within the quality standards and with similar quality to that of meat from animals raised in controlled environment.

Growing-finishing performance and carcass yield of pigs reared in a climate-controlled and uncontrolled environment.

The objective of this study was to evaluate the effect of temperature on the performance and carcass yield of pigs housed in different environments. Twenty castrated male pigs of the Topigs line were assigned to two treatments: T1, controlled environment, and T2, uncontrolled environment containing a shallow pool. A completely randomized design consisting of two treatments and ten repetitions each was used. The data were submitted to analysis of variance, and means were compared by the Tukey test at a level of significance of 5 % using the SAS 9.2 program (SAS Institute, Inc., NC, USA). The results showed that rearing pigs in an uncontrolled environment during the growing and finishing phases reduced daily feed intake (1.722 and 3.164 kg, respectively) and improved feed conversion (2.15 and 2.70 kg, respectively), but did not influence the carcass yield of the animals. In conclusion, rearing pigs under different environmental conditions during the growing and finishing phases influenced animal performance without interfering with carcass yield.