GELATION OF SHARK MYOFIBRILLAR PROTEINS BY WEAK ORGANIC-ACIDS

Washed, collagen-free shark muscle protein dispersions in water formed gels associated with an increase in viscosity when the pH was lowered to 4.5 by either acetic acid or lactic acid, while citric, tartaric a nd hydrochloric acids were ineffective in causing the gelation and vis cosity rises. The increase in viscosity, as measured by the Brabender viscograph, was dependent upon the protein concentration and was a slo w process at ambient temperature. Heating of the acidified proteins up to 50 degrees C enhanced the viscosity, while at higher temperatures the gel broke as indicated by a rapid fall in viscosity as well as sep aration of water. The presence of NaCl, KCl and CaCl2 inhibited the lo w-pH-induced gelation of the proteins.