Characterization of Post-Mortem pH Evolution and Rigor Mortis Process in Botucatu Rabbit Carcasses of Different Categories.

The aim of the present study was to evaluate the characteristics of carcasses, monitor their pH evolution during the first 24 h post-mortem, and determine the time required for the establishment and resolution of rigor mortis in different categories of Botucatu rabbits. Live weight at slaughter, carcass weight, and yield were higher in 12-month-old animals compared to 3-month-old rabbits, regardless of sex. There was an effect of muscle type, age, and sex on the kinetics of muscle acidification, with the Biceps femoris showing a significantly higher pH than the Longissimus lumborum from 4 h post-mortem onward. The establishment of rigor mortis occurred at 5 h post-mortem in young rabbits and bucks and at 6 h post-mortem in does, along with pH stabilization, while the resolution of rigor occurred at 18 h post-mortem for all types of carcasses evaluated. In conclusion, Botucatu rabbit carcasses should be chilled continuously at 4 °C for a minimum of 18 h to ensure efficient rigor mortis progression and muscle-to-meat transformation throughout the carcass.

Influence of Long-Term Freezing of Carcasses in Pre- and Post-Rigor Mortis Stages on the Technological and Nutritional Parameters of the Longissimus lumborum Muscle of Botucatu Rabbits.

The aim was to assess the impact of long-term storage on the quality of Botucatu rabbit meat frozen in pre- and post-rigor stages. The stability of the technological and nutritional parameters of Longissimus lumborum (LL) muscle was analyzed over 12 months. In the post-rigor phase, the dorsal LL surface showed a higher level (p < 0.05) of redness and saturation, while the ventral surface showed a higher level (p < 0.05) of yellowness compared to the pre-rigor LL muscle. During storage, the redness and saturation in the LL muscle decreased (p < 0.05), while the yellowness increased (p < 0.05) on both dorsal and ventral surfaces. In the first six months, the pre-rigor meat had a higher pH (p < 0.05) compared to the post-rigor meat. The fresh meat showed higher (p < 0.05) shear force values in the post-rigor stage. Over the 12-month study period, the lipid oxidation, myofibrillar fragmentation index, gross energy, and levels of protein, fat, and carbohydrates increased (p < 0.05), while the shear force, mineral content, and moisture decreased (p < 0.05). Thus, rigor mortis affects meat color in Botucatu rabbits. Fresh meat in the pre-rigor stage is softer, moister, and less acidic than post-rigor meat after 24 h of chilling. Long-term freezing enhances tenderness, regardless of the rigor phase at freezing, preserving its physical, chemical, and nutritional quality, with minor changes in color, lipid oxidation, and chemical composition.

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.

Astaxanthin improves the shelf-life of tilapia fillets stored under refrigeration.

BACKGROUND: Astaxanthin, classified as a xanthophyll, has antioxidant properties about 500 times greater than α-tocopherols and ten times greater than ß-carotenes. Based on the antioxidant activity of this carotenoid, this study aimed to evaluate the shelf-life of tilapia fillets (Oreochromis niloticus) fed with astaxanthin, by determining the microbiological quality (colimetry, counts of mesophilic and psychrotrophic microorganisms), physicochemical analyses (colorimetry, pH, thiobarbituric acid reactive substances (TBARS)) and sensory analysis. RESULTS: Tilapia supplemented with astaxanthin presented a reduction in the counts of microorganisms (mesophiles and psychrotrophics) and lower lipid oxidation index (TBARS), when compared to fillets of control fish. Colorimetric changes of fillet degradation were observed, associated with increased pH during storage, as well as loss of brightness and texture in addition to worsening of appearance and odor. These deteriorating changes were minimized using astaxanthin. CONCLUSION: Our results demonstrate the beneficial performance of astaxanthin in the shelf-life of tilapia fillets stored under refrigeration. Therefore, dietary supplementation with astaxanthin (100 and 200 mg kg-1 of feed) improves the microbiological and physicochemical quality of tilapia fillets during 50 days of shelf-life. © 2022 Society of Chemical Industry.

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

The aim of this study was to evaluate possible changes in the quality of chicken breast meat containing white stripes during freezing for 12 mo. Samples of Pectoralis major muscle from male Cobb 500 broilers containing white stripes in moderate and severe degrees were used, as well as samples from a control group (normal - absence of myopathies). Part of the samples (n = 60; n = 20 for each severity degree) were analyzed on the day of collection (beginning) and the rest (n = 240) was frozen (-20°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), color, pH, water holding capacity, cooking loss, tenderness, lipid oxidation, chemical composition, cholesterol and collagen concentrations, myofibrillary fragmentation, and sarcomere length were analyzed. Microbiological analysis of samples was performed at the beginning and after 12 mo of freezing. Myopathy linked to freezing showed results of increased meat tenderness, with reduction of crude protein and mineral matter and increase of moisture, fat, and cholesterol, without affecting the meat's collagen percentages. However, these variations with the onset of myopathy do not compromise the consumption of broiled chicken breast meat, kept frozen for up to 12 mo.

Feeding behavior of lambs fed diets containing old man saltbush hay / Comportamiento ingestivo de corderos alimentados con dietas conteniendo heno de hierba-sal / Comportamento ingestivo de cordeiros alimentados com dietas contendo feno de erva-sal

Abstract Background: We hypothesized that a diet with old man saltbush hay used as an alternative source of nutrients could partially replace the concentrate in the feeding of feedlot lambs. Objective: This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate. Methods: Twenty-four castrated Santa Inês lambs at approximately eight months of age (22 ± 1.97 kg) were confined in a randomized complete design and fed diets containing 30, 40, 50, and 60% (dry matter: DM) of old man saltbush hay. Results: The intake of DM and neutral detergent fiber was not affected (p>0.05) by the level of old man saltbush hay. Intake of mineral salt decreased (p<0.01) as the proportion of old man saltbush in the diet increased. Weight gain (kg) and feed efficiency worsened (p<0.05) with 40% inclusion of old man salt bush hay. The time spent on feeding and chewing increased (p<0.05), while idle time was reduced (p<0.01) with dietary inclusion of old man saltbush. Feed efficiency decreased (p<0.05) with the inclusion of old man saltbush. Conclusion: Dietary inclusion of old man saltbush affects the feeding behavior and performance of lambs in feedlot.

Resumen Antecedentes: Nuestra hipótesis consistió en que una dieta con heno de hierba-sal como fuente alternativa de nutrientes puede sustituir parcialmente el concentrado en la alimentación de corderos confinados. Objetivo: Evaluar el comportamiento ingestivo de corderos alimentados con dietas conteniendo niveles incrementales de heno de hierba-sal asociado al concentrado. Métodos: Veinticuatro corderos Santa Inés, castrados, con aproximadamente ocho meses de edad, peso corporal de 22 ± 1,97 kg, confinados, fueron distribuidos en un arreglo experimental completamente aleatorizado y alimentados con dietas conteniendo 30, 40, 50 y 60% (materia seca: MS) de heno de hierba-sal. Resultados: El consumo de MS y fibra detergente neutra no se vió afectado (p>0,05) por los diferentes niveles de inclusión de hierba-sal. La ingestión de sal mineral se redujo (p<0,01) al incrementar la hierba-sal en la dieta. La ganancia de peso (kg) y la eficiencia alimenticia empeoraron (p<0,05) con la inclusión de 40% de heno de hierba-sal. El tiempo empleado para las actividades de alimentación y masticación aumentó (p<0,05), mientras que el de ocio se redujo (p<0,01) con la inclusión de hierba-sal. La eficiencia alimenticia de la materia seca disminuyó (p<0,05) a medida que aumentó el nivel de inclusión de heno de hierba-sal. Conclusión: La inclusión de heno de hierba-sal en la dieta afecta el comportamiento ingestivo y el rendimiento de corderos confinados.

Resumo Antecedentes: A hipótese foi que uma dieta com o feno de erva-sal como fonte alternativa de nutrientes poderia substituir parcialmente o concentrado na alimentação de cordeiros confinados. Objetivo: Este estudo foi desenvolvido para avaliar o comportamento ingestivo de cordeiros alimentados com dietas contendo feno de erva-sal associado com o concentrado. Métodos: Vinte e quatro cordeiros Santa Inês, castrados, com aproximadamente oito meses de idade, peso corporal de 22 ± 1,97 kg, confinados, foram distribuídos em um delineamento experimental inteiramente casualizado e alimentados com dietas contendo 30, 40, 50 e 60% (matéria seca (MS)) de feno de erva-sal. Resultados: O consumo de matéria seca e fibra em detergente neutro não foram comprometidos (p>0,05) pelos diferentes níveis de erva-sal. A ingestão de sal mineral reduziu (p<0,01) com o aumento de erva sal nas dietas. O ganho de peso e a eficiência alimentar pioraram (p<0,05) a partir da inclusão de 40% de feno de erva-sal na dieta dos cordeiros. O tempo despendido para as atividades de alimentação e mastigação aumentaram (p<0,05), enquanto que o de ócio reduziu (p<0,01) com a inclusão da erva sal nas dietas. A eficiência de alimentação da matéria seca diminuiu (p<0,05) à medida que se incluiu o feno de erva-sal. Conclusão: A inclusão de feno de erva-sal na dieta afeta o comportamento ingestivo eo desempenho de cordeiros confinados.

Effect of Aging on the Quality of Breast Meat from Broilers Affected by Wooden Breast Myopathy.

This study aimed to evaluate the effects of aging on the quality of breast meat from broilers affected of wooden breast. Samples that were classified as normal (control), moderate (hardness verified only in one region of breast fillet), and severe (hardness verified in all the extension of breast fillet) were evaluated fresh and after three and seven days of aging. Normal samples and samples with a moderate degree of myopathy showed greater water-holding capacity, which may benefit the processing industry of poultry meat. During the aging process, increase was observed in total collagen concentration (from 0.41% in normal samples to 0.56% in samples with severe degree). Samples of chicken breast affected by moderate degree showed higher myofibril fragmentation index (MFI = 115) than normal chicken samples (95.65). Although chicken samples affected with severe degree of wooden breast myopathy are more tender than normal chicken breasts, they produce more exudate, which can be detrimental to the processing of poultry meat. The aging process may improve the reduction of cooking weight loss and protein loss in exudation of broilers' breasts affected by wooden breast myopathy.

Breast meat quality of turkey breeder hens at disposal age affected by deep pectoral myopathy.

Deep pectoral myopathy (DPM) considerably affects the meat quality of commercial poultry, thus representing a challenge to the poultry industry. In this study, we examined the breast meat quality of turkey breeder hens at disposal age affected by different degrees of DPM. Samples were collected from Nicholas turkeys at disposal age (385 d), at an average weight of 12.5 kg, which were reared and slaughtered in the south region of Brazil. The breast was first classified according to the degree of DPM and then samples of the Pectoralis major were collected from birds affected (DPM degrees 2 and 3; n = 20 of each) and nonaffected (normal, absence of lesions; n = 20) by the myopathy. After the affected Pectoralis minor muscle was discarded, the carcasses were released for human consumption by the Federal Inspection Service. The meat affected by the myopathy exhibited color changes (L*, a* and b*) (P < 0.05), especially in the inner surface. Higher (P < 0.05) water-holding capacity, pH, sarcomere length and fat concentration and lower (P < 0.05) shear force and moisture percentage were observed when compared to the normal samples. From this study, can be concluded that the severe condition of deep pectoral myopathy which affects the Pectoralis minor muscle, causes variations in the quality of Pectoralis major muscle of turkey on disposal age. As a raw material, this type of meat has a higher fat content and greater capacity for retaining intracellular water, important attributes to the manufacture of processed products. In this way, the processing is an economically viable alternative to the commercialization of breast meat from birds affected by myopathy.

Physical, Chemical and Histological Characterization of Pectoralis major Muscle of Broilers Affected by Wooden Breast Myopathy.

This study aimed to characterize the effects of wooden breast myopathy (WBM) on quality of broiler chicken breast meat. Normal samples (absence of myopathy), moderate-degree samples (hardness only in one area of the breast fillet) and severe-degree samples (hardness throughout the breast fillet) were classified. In macroscopic analysis, the pectoral muscle affected by the WBM showed, in general, pale color with stiff, irregular and reddish regions (suffusions and petechiae), with the presence of white striations. In microscopic analysis, the myopathy was characterized by loss of the polygonal aspect of the muscle fibers. Samples with moderate degree of the myopathy showed greater (p = 0.0266) water retention capacity. There was an increase (p = 0.004) in total collagen concentration in samples from the severe-degree group 0.29% in normal samples to 0.43 and 0.48% in samples from moderate- and severe-degree groups, respectively. Samples of chicken breast affected by the severe-degree WBM showed lower (p < 0.0001) myofibrillar fragmentation index (64.51) and lower (p = 0.0002) fat concentration (2.17%) than normal chicken samples (80.45 and 3.79%, respectively). Samples affected by WBM are larger and heavier and present poorer physical quality when compared to normal chicken meat. Histologically it is possible to observe loss of the polygonal aspect of muscle fibers.

Effects of Storage on Quality Traits of Sausages Made with Chicken Breast Meat Affected by Wooden Breast.

The aim of this study was to examine the effects of storage on the quality of sausages made with breast from chickens affected by wooden breast myopathy (WBM). Breast samples from male broilers slaughtered at 48 days old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree samples (hardness over the entire length of the breast) were processed into sausages and evaluated prior to storage and after being vacuum-packed and stored for 7, 14, 21 and 28 days at 4 °C. There was a decrease (p < 0.001) in pH and an increase (p < 0.001) in cooking weight loss in samples of sausages, regardless of the myopathy, after 28 days of storage. Sausages produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) moisture concentration (72% for the severe degree) and higher (p = 0.0224) protein concentration (17.27% and 17.36%, respectively, for the moderate and severe degrees) than sausages made of normal samples (70.72% and 14.32%, respectively). The results indicate that sausages produced with meat from birds moderately and severely affected by the myopathy show higher oxidative stability. Fresh sausages produced with breast meat from birds affected by wooden breast syndrome may be stored (4 °C) for up to 28 days without exhibiting the characteristic rancid taste and smell. In sensory analysis, no differences were observed between the formulations, which suggests that the consumers approved the samples regardless of the disease severity in the meat used for the making of the sausages. The current results show that chicken meat affected by wooden breast myopathy can be used for producing fresh sausages in the industry.

Quality of turkeys breast meat affected by white striping myopathy.

The aim of this study was to characterize the breast meat of turkeys affected by different degrees of severity (normal [NORM], moderate [MOD], and severe [SEV]) of the white striping (WS) myopathy, as well as to evaluate the influence of this myopathy on meat quality. Twenty-nine samples of the pectoralis major muscles of each treatment were obtained from Nicholas breed male and female turkeys, reared and slaughtered in the center-west region of Brazil. The whole breasts of the turkeys were used for macroscopic classification, weight evaluation, and morphometric measurements. Then, the pectoralis major muscle was separated for histological evaluation and qualitative physicochemical analyses, namely ventral and dorsal color (L∗, a∗, and b∗), pH value, water holding capacity (WHC), cooking loss (CL), shear force (SF) (Meullenet-Owens Razor Shear [MORS] and Warner-Bratzler), sarcomere length, total, soluble, and insoluble collagen contents, proximate composition (protein, lipids, moisture, and ash), cholesterol content, and fatty acid profile. The results showed that muscles affected by myopathy, both MOD and SEV, exhibited larger weights (around 2.8 kg) compared to NORM muscles (1.3 kg) and a significant increase (P < 0.05) in the diameter of the fibers. The increase in the degree of severity of the myopathy increased (P < 0.05) the value of L∗ of the dorsal part and ventral part of the muscle. No differences (P > 0.05) were observed in the pH, CL, and WHC values of the muscles, whereas the MORS and Warner-Bratzler SF of the SEV fillets resulted in significantly lower shear values (P < 0.05) compared to the NORM fillets. In addition, the MOD and SEV fillets presented lower values of protein (P < 0.05) than NORM fillets. No significant differences (P > 0.05) were observed for moisture and lipid and cholesterol contents. Meat with MOD and SEV severity of WS myopathy had higher (P < 0.05) concentrations of total and insoluble collagen. Thus, the presence of WS myopathy in MOD and SEV degrees affected a large part of the histological and quality characteristics evaluated.

Meat quality of lambs fed phytogenic additives / Qualidade da carne de cordeiros alimentados com aditivos fitogênicos

The study was developed in the Sheep Production Laboratory of the Department of Animal Science, College of Agricultural and Veterinary Sciences, São Paulo State University, Jaboticabal, SP, Brazil. Thirtytwo non-castrated Ile de France lambs weighing 20.0 ± 0.2 kg received 4 diets with a roughage: concentrate ratio of 40: 60. The experimental treatments consisted of D1: corn silage + concentrate; D2: corn silage + concentrate + 30 mg rosemary extract kg body weight1; D3: corn silage + concentrate + 30 mg green tea extract kg body weight-1; and D4: corn silage + concentrate + 30 mg oregano extract kg body weight-1, up to 35.0 ± 0.2 kg body weight. The objectives were to evaluate rib eye area, cholesterol content, lipid oxidation, qualitative parameters, as well as perform sensory analysis, centesimal composition, and fatty acid profile of the meat. The experimental design was completely randomized with four treatments and eight replicates. The treatments were compared by Tukey's test through the SAS software (Statistical Analysis System Institute [SAS], 2003). Inclusion of phytogenic additives into the diets did not affect the qualitative parameters cholesterol content, lipid oxidation, and centesimal composition (except for protein content, which was lower in D2, 22.57%, compared to D1, 25.62%), as well as meat fatty acid profile (except for C18: 1n7 cis-vaccenic). The use of phytogenic additives provided suitable qualitative parameters. Moreover, despite the well-known positive effect of antioxidants in the diet, phytogenic additive inclusion was ineffective in reducing lipid oxidation in lamb meat. However, further studies with different inclusion percentages should be carried out to find out how to increase shelf life without harming lamb qualitative parameters, especially regarding the sensory analysis.(AU)

O trabalho foi realizado no Laboratório de Produção Ovina, pertencente ao Departamento de Zootecnia da FCAV, Unesp, Câmpus de Jaboticabal, SP. Trinta e dois cordeiros Ile de France, machos não castrados, com 20,0 ± 0,2 kg receberam 4 dietas, com relação volumoso:concentrado 40:60, sendo os tratamentos constituídos por D1: silagem de milho + concentrado, D2: silagem de milho + concentrado + 30 mg de extrato de alecrim kg peso corporal-1, D3: silagem de milho + concentrado + 30 mg de extrato de chá verde kg de peso corporal-1 e D4: silagem de milho + concentrado + 30 mg de extrato de orégano kg de peso corporal-1, até atingirem 35,0 ± 0,2 kg de peso corporal. Os objetivos foram avaliar a área de olho de lombo, o teor de colesterol, a oxidação lipídica, os parâmetros qualitativos, bem como a análise sensorial, a composição centesimal e o perfil de ácidos graxos da carne. O delineamento experimental foi o inteiramente casualizado, com quatro tratamentos e oito repetições, sendo as comparações entre as médias dos tratamentos feitas pelo teste Tukey a 5 %, e as análises de variância conforme procedimentos do SAS Software (Statistical Analysis System Institute [SAS], 2003). A inclusão de aditivos fitogênicos na dieta de cordeiros não afetou os parâmetros qualitativos da carne, o teor de colesterol, a oxidação lipídica e a composição centesimal (com exceção do teor de proteína que foi menor na D2, 22,57%, em relação à D1, de 25,62%) e o perfil de ácidos graxos (com exceção do C18:1n7 cis-vacênico). O uso dos aditivos fitogênicos na dieta dos cordeiros propiciou adequadas características qualitativas da carne ovina, e apesar do conhecido efeito positivo do uso de antioxidantes na dieta de cordeiros, a inclusão dos aditivos fitogênicos não foi eficaz em reduzir a oxidação lipídica da carne, entretanto, novos estudos com diferentes porcentagens de inclusão devem ser conduzidos para averiguar como aumentar a vida de prateleira da carne sem prejudicar as características qualitativas da carne, principalmente em relação à análise sensorial.(AU)

Physicochemical Properties and Consumer Acceptance of Hamburgers Processed with Chicken Meat Affected by Wooden Breast Myopathy.

Considering the increased incidence of wooden breast myopathy in broilers, the intake involves no threat to human health, indefinite etiology consumer rejection by appearance in such breasts, and the lack of studies on the industrial use of wooden breast. The objective of this study was evaluating the quality of hamburgers made with chicken meat affected by wooden breast. Breast samples from broilers slaughtered at 48-days-old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree (hardness over the entire length of the breast) samples were processed for the manufacture of hamburgers whose quality analyses (color, pH, cooking weight loss, shrinkage percentage, tenderness, storage weight loss, water activity, lipid oxidation, chemical composition and consumer test) were performed on non-stored samples (Day 0), and after storing at 30, 60, 90 and 120 days at -20 °C. There was a reduction (p < 0.05) in tenderness in samples of moderate-grade hamburgers (from 161.45 N to 289.40 N) after 120 days of storage. Hamburgers produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) fat concentration (5.32 g/100 g and 5.26 g/100 g, respectively, for the moderate and severe degree) than hamburgers made of normal samples (4.45 g/100 g). Lipid oxidation values increased, which exceeded the limit of rancidity detection, independent of myopathy. The consumers equally appreciated the aroma, flavor, and texture, and rated their overall acceptance as similar regardless of the quality of chicken meat. Chicken breast hamburgers with wooden breast myopathy is a viable alternative for the poultry industry.

Lipid Assessment, Cholesterol and Fatty Acid Profile of meat from broilers raised in four different rearing systems.

Evaluated lipid and cholesterol concentration and fatty acid profile of raw breast, thigh and drumstick meat from broilers raised in different rearing systems. Were used 200 male broiler carcasses from four different rearing systems (n=50 from conventional intensive; n=50 from organic; n=50 from free-range; and n=50 from antibiotic-free) distributed in a completely randomized design with four rearing systems and 50 replications (carcasses). Breast meat from conventional broilers showed higher lipid (1.47) and cholesterol (34.13) concentration. Thigh and drumstick meat from free-range broilers had higher lipid (7.53/4.73) and cholesterol (45.55/53.65) concentration. Fat contained in breast, thigh and drumstick meat from free-range broilers showed higher levels of polyunsaturated fatty acids. Fat from breast and thigh meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Fat from thigh meat from organic broilers showed higher levels of EPA (C20:5n3) and DHA (C22:6n3). Fat from drumstick meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Meat from chickens raised in alternative rearing systems offers less risk to cardiovascular health because it presents lower concentrations of lipids and cholesterol, greater amounts of polyunsaturated fatty acids, which are beneficial for human health.

Percentual de gordura e colesterol e maciez do peito de frangos de diferentes linhagens genéticas contendo estrias brancas / Fat and cholesterol content and softness of breast meat from broiler chickens, of different genetic lineages, affected by white striping

Foram utilizadas amostras de peito de frangos de corte de três linhagens genéticas contendo diferentes graus de estrias brancas aparentes na superfície do músculo. Foram avaliados concentração de colesterol, percentual de gordura e força de cisalhamento (maciez). Com o aumento do grau de severidade da miopatia ocorreu o aumento de gordura e, consequentemente, da maciez da carne de peito de frangos Cobb 500 e Hubbard. Há variação da concentração de colesterol dependendo do acometimento por estrias brancas, a qual precisa ser melhor estudada. As estrias brancas aparentes na superfície do peito estão associadas à maior deposição de gordura na carcaça do frango, o que, consequentemente, pode influenciar a maciez da carne.(AU)

Efeito do congelamento por três meses sobre a coloração, gordura e concentração de colágeno da carne de peito de frangos de corte acometidos pela miopatia White Striping / Effect of freezing for three months on the color, fat and collagen concentration of breast meat from broilers affected by White Striping myopathy

Foram utilizadas amostras de peito de frangos de corte acometidos pela miopatia “White Striping” (estrias brancas em seus diferentes graus de severidade) para análise de coloração (L*, a* e b*), lipídeos totais e concentração de colágeno. Amostras de filés acometidos pela miopatia foram avaliadas logo após o abate e outras foram armazenadas congeladas (-20°C) durante três meses. Com a severidade da miopatia ocorre o aumento da concentração de gordura e, consequentemente, alteração da coloração da superfície do peito, além da redução do percentual de colágeno. O congelamento da carne de peito por três meses provoca alterações de cor da superfície dos filés. A produção de exsudato, oriunda do descongelamento, resulta no aumento da concentração de componentes como colágeno solúvel e lipídeos.(AU)

Efeito do congelamento sobre variáveis relacionadas à cor e à maciez da carne de frangos acometidos pela miopatia “Peito de Madeira” / Effect of freezing on the variables related to color and tenderness of meat from broilers affected by Wooden Breast myopathy

O estudo foi realizado com o objetivo de avaliar os efeitos dos diferentes graus de severidade da miopatia “Peito de Madeira” (moderado e severo) sobre a qualidade da carne de frango, logo após o abate e após congelamento por três meses, uma vez que o prazo de validade determinado pela indústria para carne de frango congelada é de até 12 meses, de modo a comprovar se há possibilidade de armazenar esse tipo de carne sem que ocorram alterações que comprometam o consumo seguro, além de alterações de aparência, suculência e maciez. Foram realizadas análises de cor (L*, a* e b*), perda de peso por cozimento (PPC) e força de cisalhamento (FC). Com o aumento do grau de severidade da miopatia em peitos de frango, observou-se diferenças significativas para as variáveis de cor, aumento de PPC e diminuição da FC, antes e após o congelamento.(AU)

Efeito do congelamento por três meses sobre a coloração, gordura e concentração de colágeno da carne de peito de frangos de corte acometidos pela miopatia White Striping / Effect of freezing for three months on the color, fat and collagen concentration of breast meat from broilers affected by White Striping myopathy

Foram utilizadas amostras de peito de frangos de corte acometidos pela miopatia “White Striping” (estrias brancas em seus diferentes graus de severidade) para análise de coloração (L*, a* e b*), lipídeos totais e concentração de colágeno. Amostras de filés acometidos pela miopatia foram avaliadas logo após o abate e outras foram armazenadas congeladas (-20°C) durante três meses. Com a severidade da miopatia ocorre o aumento da concentração de gordura e, consequentemente, alteração da coloração da superfície do peito, além da redução do percentual de colágeno. O congelamento da carne de peito por três meses provoca alterações de cor da superfície dos filés. A produção de exsudato, oriunda do descongelamento, resulta no aumento da concentração de componentes como colágeno solúvel e lipídeos.