Hydrolysis of butteroil using a calf pregastric esterase immobilized in a hollow fiber reactor

A calf pregastric esterase immobilized in a hollow fiber reactor was employed to lipolyze the triglycerides in butter oil. The pregastric esterase was partially purified from a crude extract using microfiltration. The filtrate was then concentrated using ultrafiltration. The esterase was immobilized by adsorption on polypropylene hollow fibers.; The effects of the reactor space time, the time since the enzyme was immobilized, and the pH and glycerol concentration of the buffer solution were characterized in terms of both their influence on the overall rate of release of fatty acids and the rates of release of specific fatty acids. The kinetic models proposed to describe the two types of rate effects are of the Michaelis-Menten form that accounts for product inhibition. Deactivation of the enzyme was observed to follow a first order model. Nonlinear regression analyses were used to determine the kinetic parameters of rate expressions based on proposed mechanisms.; Although both the pH and the glycerol concentration in the buffer solution significantly affect the rate of release of fatty acids, the effects of these two factors on the rate of enzyme deactivation was the governing factor in selecting the optimum operating conditions (pH 6.0 and a glycerol concentration of 150 g/l). For these conditions, a pseudo space time of 17 hours produces a lipolyzed butter oil with a quality comparable to that of a commercially available product.; Estimates of the capital investment and operating costs were prepared for both immobilized and soluble enzyme processes. The immobilized enzyme process is more expensive than the conventional soluble enzyme process. The high capital cost associated with the hollow fiber reactor is the main reason for this outcome. A 20-fold increase in enzyme activity would be required to make the immobilized enzyme technology competitive for the production of lipolyzed butter oil.