Ionic Strength Effects on Heat-induced Gelation of Myofibrils and Myosin from Fast- and Slow-twitch Rabbit Muscles |
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Authors: | C BOYER S JOANDEL A OUALI J CULIOLI |
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Affiliation: | The authors are affiliated with Station de Recherches sur la Viande, INRA, 63122 Saint-Genès-Champanelle, France. Direct inquiries to Dr. J. Culioli. |
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Abstract: | The effects of ionic strength on myofibrils and myosin from rabbit fast-twitch Psoas major (PM) and slow-twitch Semimembranosus proprius (SMp) muscles before and after heating were studied by electron microscopy and thermal scanning rheometry. The direct suspension of proteins in low ionic strength (0.2M KCl; pH 6.0) led to very weak gels, whereas a gradual lowering of the ionic strength (by dialysis against 0.2M KCl; pH 6.0) of 0.6M KCl protein solutions induced strand-type networks at low temperature and strong heat-induced gels. As shown by transmission and scanning electron micrographs, in low ionic strength, SMp myosins formed shorter filaments before heating and thinner and shorter structures in heat-induced gels, as well as a lower gel porosity than PM myosins. |
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Keywords: | heat-induced gelation myosin myofibrils rabbit muscles ionic strength |
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