Effect of ultrasonication on secondary structure and heat induced gelation of chicken myofibrils.

Ultrasonication has been suggested as a new promising technique to improve the quality of meat and other meat products. In this study ultrasonication at low frequency (20 kHz) was carried out to investigate the effect on structural and biochemical properties of myofibril proteins. The possible implications between ultrasonication-induced structural changes and gelation properties were also investigated. Structural changes were investigated by ATPase activity, SDS-PAGE, circular dichroism and fluorescence spectroscopy. Microstructural changes in heat induced gels were observed by SEM and water holding capacity was determined by centrifugation. Ultrasonic treatment for 30 min significantly reduced the Ca2+-ATPase activity. Moreover significant change in structure of proteins at secondary level, as indicated by marked decrease in α-helicity, was observed. Marginal change in fluorescence at 10 min was followed by significant increase at 20 and 30 min reflecting exposure of hydrophobic residues on surface during unfolding. Microstructural analyses of gels showed marked improvement in regular three dimensional network at 20 and 30 min of sonication. WHC at 20 min and 30 min were significantly higher than control. Our results suggest that ultrasonication at low frequency (20 kHz) can prove beneficial for improving functional properties of meat and meat products.