ULTRASTRUCTURAL-CHANGES OF MYOFIBRILLAR PROTEIN GELLED WITH 1,5-GLUCONO-DELTA-LACTONE AT CHILLED TEMPERATURES

Changes in the ultrastructure of myofibrillar protein as a result of I ,5-glucono-delta-lactone-induced gelation at chilled temperatures were investigated using transmission electron microscopy. The myofibril st ructure appeared to have completely disintegrated at pH 4.0 resulting in a granular, amorphous appearance. It was suggested that as the pH w as lowered to about 4.5, partial extraction of the A-band proteins occ urred A composite system of a myosin gel network reinforced by the res idual myofibrillar structure was proposed to have formed. As the pH wa s lowered further, complete depolymerisation of actomyosin was suggest ed to have resulted in the formation of a predominantly myosin gel. Th e inclusion of sodium chloride resulted in swelling of the myofibrilla r protein and retention of the myofibrillar structure to pH 3.8.