The effect of ATP marination on the depolymerization of actin filament in goose muscles during postmortem conditioning
In order to study the tenderization mechanism of ATP treatments by depolymerizing actin filaments, breast muscles of Eastern Zhejiang White Geese were randomly divided into 3 groups: control, 10 and 20 mM groups. Shear force (SF), sarcomere length (SL) and myofibrillar fraction index (MFI), the content of F-actin and G-actin, the expression of actin associated proteins (cofilins and tropomodulins) were investigated during conditioning. In 20 mM group, cofilins content increased from 48 to 168 h, while tropomodulins decreased; the content of F-actin decreased from 24 to 168 h, while the increased G-actin was observed upto 48 h. In the control, the degraded tropomodulins were observed at 168 h, and the increased cofilins and G-actin were detected at the same time; the increase of MFI and decrease of F-actin content were shown at 96 and 168 h. Compared to control group, 20 mM group accelerated the transformation of F-actin into G-actin; it showed higher SL and MFI, and lower SF at 48, 96 and 168 h, respectively. We concluded that depolymerization of actin filaments, which was regulated by cofilins and tropomodulins, contributed to myofibrillar fraction and low SF during conditioning.