Hydrolysis of lipids from beef fat by pancreatic lipase was studied. The maximum release of free fatty acids was shown to occur at 40degreesC for the first 3 h of the experiment. After this, transetherification was predominant. The main kinetic parameters were the following: maximum hydrolysis rate, V = 1.25 +/- 0.1 mg fat/ml min; Michaelis constant, K-M(H) = 100 +/- 12 mg fat/ml; constant of substrate inhibition, K-S = 10.0 +/- 0.8 mg fat/ml; equilibrium constant, K-p = 277 +/- 170 mg fat/ml; and activation energy of beef fat hydrolysis by pancreatic lipase, E-a = 19.1 +/- 1.1 kJ/mole. The kinetic method used could be applied to development of the method for biotransformation of poorly assimilated fats into more valuable products.