RESUMO
High pressure processing (HPP) of pre-rigor longissimus thoracis (strip loin) from prime and bull animals substantially decreased the shear force and improved consumer eating attributes of the final meat product. The improved tenderness in both prime and bull meat was associated with a lower myofibrillar fragmentation index and reduced calpain 1 activity which indicated the mechanism of tenderisation was different from that which occurred in chill aged meat. Light microscopy showed disruption to the fibre packing within the muscle and electron microscopy confirmed significant disruption of the Z discs and M lines and disappearance of the A lines. Thus, HPP is associated with a reduction in the structural integrity and strength of the sarcomeres. These effects were consistent in strip loins sourced from prime and bull stock. HPP also led to the movement of glycogen phosphorylase from the sarcoplasmic fraction to the insoluble myofibrillar fraction in all animals and this was associated with a higher pH at 24â¯h.
Assuntos
Músculos do Dorso/química , Qualidade dos Alimentos , Produtos da Carne/análise , Indústria de Embalagem de Carne/métodos , Carne/análise , Estresse Mecânico , Animais , Músculos do Dorso/metabolismo , Músculos do Dorso/ultraestrutura , Calpaína/metabolismo , Bovinos , Culinária , Feminino , Preferências Alimentares , Glicogênio Fosforilase/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Mastigação , Microscopia Eletrônica de Transmissão , Miofibrilas/química , Miofibrilas/metabolismo , Miofibrilas/ultraestrutura , Nova Zelândia , Sarcômeros/química , Sarcômeros/metabolismo , Sarcômeros/ultraestrutura , Espectrometria de Massas em TandemRESUMO
Strip loins from different grades of cattle were subjected to two levels of high pressure processing (HPP) within 1h of slaughter at a commercial meat processing plant and chilled for 1day before freezing. The physical and eating quality characteristics of longissimus thoracis (strip loin) steaks from HPP were compared to meat that was chill aged for 1 or 28days. HPP produced meat after 1day with 60% lower shear force and higher sensory eating quality scores than 1day chill aged meat. Extended chill storage for 28days produced steaks of similar tenderness to HPP meat. HPP also increased the ultimate pH and decreased the cooking loss. Chilled storage of the gluteus medius from prime cattle for 28days significantly improved the shear force by 18%, whilst HPP improved both the shear force by 43% and the sensory eating quality scores. HPP can produce high eating quality eye of rump medallions within 1day of slaughter.
