| Popis: |
When homogenised muscle (pH 5·5) was heated at 55°C, connectin was extensively degraded, whereas actin and myosin heavy chains were apparently unaffected. It was concluded that carboxyl proteases (e.g. cathepsin D) were largely responsible, because the breakdown of connectin was inhibited by the addition of pepstatin. When whole muscle samples were heated at 50–70°C, degradation of connectin was inversely related to the ultimate pH of the source muscle, again indicating the role of carboxyl proteases. The greater activity of carboxyl proteases in tissues from older animals was apparently responsible for the more extensive degradation of connectin in muscle from older sheep. Because connectin is extensively degraded in cooked meat, it is unlikely to contribute to meat toughness. |
