Whey protein concentrate as a proteinase inhibitor in Pacific whiting surimi

The most effective inhibition of autolytic proteinase activity was found at 3% whey protein concentrate (WPC) with residual proteinase activity at 14.2%. WPC reduced papain and trypsin activities linearly with lowest residual activities of 8.7% and 41.4%, respectively. An unidentified high-molecular-weight protein was inhibitory for papain and trypsin with no inhibitory components detected at the region <M(r) 100,000. The highest shear strain of surimi was obtained with WPC at 4%. The values were 1.89 when rapidly cooked at 90 degrees C for 15 min and 1.62 when pre-heated at 60 degrees C for 30 min prior to cooking at 90 degrees C.