Biochemical and technological view of broiler chicken meat with pectoral / Visão bioquímica e tecnológica de carne de frango com anomalias peitorais

ABSTRACT: There has been a significant advance in the poultry industry, and new technological and biological processes have accompanied the development of animals and inputs. Alongside the new possibilities for growth, there has been an emergence of new paradigms, including the rise of myopathies among which PSE, DFD, deep pectoral myopathy, oregon disease, acid breast, white stripping, wooden breast and spaghetti meat stand out. They cause considerable damage to the industry, as well as to ride hypotheses for studies in an attempt to better describe them. Researches seek to know about the behavior of proteins and specific protein groups in these anomalies. Groups of proteases are determinant to understand what may be occurring in muscle activity and; consequently, to understand the process in a more detailed way. Therefore, proteolytic systems may be acting on abnormal tissues. Proteases act differently in birds and mammals, but how altered they may be is still unknown. Besides, it is essential to relate the activities of these proteases, measures that indicate technological aspects that are relevant to meat quality standards. These quality standards must be directly associated with the consumption of raw meat in the material destined for processing, regardless of the final product. The important thing is to guarantee information that will lead the industry and consumers that will have, even with the anomaly developed, products that are nutritionally safe . This review discusses the biochemical and technological changes in poultry with pectoral anomalies, and how this affectsmeat quality.

RESUMO: Sabe-se que houve um avanço considerável na indústria de frangos de corte nos últimos sessenta anos, e que consequentemente novos processos tecnológicos e biológicos acompanharam o desenvolvimento tanto de animais quanto de insumos. Com novas possibilidades de crescimento houve também o surgimento de novos paradigmas, sendo um deles o surgimento de diferentes tipos de miopatias. Como o peito é um dos pontos fortes da indústria de aves, muito tem se estudado sobre o assunto, e pode-se destacar PSE, DFD, Miopatia peitoral profunda ou peito verde, Peito ácido, White striping, Wooden breast e Spaghetti meat são as mais comuns. As três ultimas são mais recentes quando comparadas as outras citadas, e ainda há necessidade de compreensão do seu desenvolvimento, mas sabe-se que acarretam prejuízos consideráveis para o setor, além de permear a mente dos pesquisadores com hipóteses para estudos na tentativa de descrever melhor o que ocorre, o porquê de sua ocorrência e, futuramente, compreende-la ao ponto de poder gerar mecanismos para minimiza-las ou até mesmo suprimi-las. Os grupos de pesquisa nos USA, Italia, Brasil, Finlândia, Canadá e Inglaterra estão em busca destas respostas, todavia, até o momento, a Itália é o país que mais tem reportado informações sobre a problemática em torno de White striping e Wooden breast. Mas com todos os artigos até o presente momento, pouco se sabe sobre o comportamento de proteínas e grupos proteicos específicos nestas anomalias. O que há descrito trata-se de diferença entre conteúdo proteico e colágeno e taxa de degradação proteica. Contudo, sabe-se que grupos de proteases são determinantes para compreender o que pode estar ocorrendo na atividade muscular e consequentemtne entender o processo de forma mais detalhada. Logo, uma possibilidade é a compreensão de sistemas preoteolícos como as calpaínas, caspases e como podem estar atuando nos tecidos anômalos. Sabe-se que estas proteases atuam de maneira diferenciada em aves, quando comparada a mamíferos, mas o quão alterada podem estar ainda não se sabe. Além disto, é importante relacionar a atividades destas proteases com medidas que indiquem aspectos tecnológicos que sejam relevantes para padrões de qualidade de carnes. Estes padrões de qualidade devem estar diretamente associados ao consumo da carne in natura quanto ao material destinado à processamento, não importando qual seja o produto final. O mais importante é garantir informações que levem a indústria e os consumidores que terão, mesmo com a anomalia desenvolvida, produtos seguros nos aspectos nutricionais, bioquímicos e tecnológicos. Com base nestas breves informações, foi definido o procedimento metodológico desta proposta que permeia aspectos que incluam o maior número de informações sobre a alteração White striping em carne de aves, e com a reunião destas informações a possibilidade de entender melhor o que ocorre nestas carnes, levando a um conjunto de analises ainda não relatado na atual literatura.

Influence of Cooling on the Glycolysis Rate and Development of PSE (Pale, Soft, Exudative) Meat

The aim of this work was to evaluate pH values fall rate in chicken breast meat under commercial refrigeration processing conditions and the development of PSE (pale, soft, exudative) meat. Broiler breast samples from the Cobb breed, both genders, at 47 days of age (n = 100) were taken from refrigerated carcasses (RS) immersed in water and ice in a tank chilled at 0°C (±2). pH and temperature (T) values were recorded at several periods throughout refrigeration in comparison to samples left at room T as control (CS). The ultimate pH (pHu) value of 5.86 for RS carcasses were only reached at 11°C after 8.35 h post mortem (PM) while, for CS samples, pHu value was 5.94 at 22°C after 4.08 h PM. Thus, under commercial refrigeration conditions, the glycolysis rate was retarded by over 4.0 h PM and the breast meat color was affected. At 24.02 h PM, PSE meat incidence was 30% while for CS, meat remained dark and PSE meat was not detected. Results show retardation in the glycolysis rate and PSE meat development was promoted by the refrigeration treatment when compared with samples stored at processing room temperature.

Broiler chicken PSE (Pale, Soft, Exudative) meat and water release during chicken carcass thawing and brazilian legislation

The objective of this work was to investigate the relationship between poultry PSE meat and water loss of frozen chicken carcass in two experiments. The first experiment was carried out in commercial abattoir. Poultry carcass were classified as PSE meat (n=59) (pH <5.8) and control samples (n=55) (pH >5.8). Water absorption and drip test were performed according to the Brazilian legislation methodologies. The second experiment was carried out with commercial whole five brands frozen carcasses purchased from the local supermarkets (n=30) and analyzed for pH, water holding capacity (WHC) and drip test. PSE poultry meats absorbed 3.59% of water during the processing similar to the control samples; however, released 0.38% more water during thawing of the carcasses. From these five brands evaluated, three presented drip values above 6.0%. The highest drip value was showed by the brand sample that had pH and WHC values characteristics of PSE meat. It could be postulated that PSE meat phenomenon promoted more water release during thawing leading to a misinterpretation in relation to the Brazilian legislation for water carcass liberation during thawing.