title: Temperature shows greater impact on bovine Longissimus dorsi muscle glycogen debranching enzyme activity than does salt concentration.
abstract: The degradation of glycogen progresses by the co-operation of two enzymes: glycogen phosphorylase (phosphorylase) and glycogen debranching enzyme (GDE). We studied the effect of temperature (4-42°C) and salt concentration (0-3% NaCl) on bovine M. longissimus dorsi GDE activity. GDE activity (n=4) decreased significantly with decreasing temperature from about 40-4°C. GDE exhibited 52% activity at 25°C and 11% at 4°C compared to its optimum activity measured at 39°C. In rapidly chilled meat, the reduction in GDE activity may substantially delay the rate of glycolysis. However, residual GDE activity at 4°C seems sufficient to enable the attainment of normal ultimate pH if the available time is long enough. An increase in salt concentration from 0% to 2% and to 3% induced a significant (P<0.001) increase in the ultimate pH of ground bovine meat (n=6), but showed no effect on GDE activity.
authors: Department of Food Technology, University of Helsinki, P.O. Box 66 (Viikki EE), 00014, Finland.
authors: M
authors: M
authors: Ylä-Ajos
authors: E
authors: E
authors: Puolanne