Thermal resistance of partially purified proteinase of Pseudomonas fluorescens P-26.

Abstract

Heat resistance of the Pseudomonas fluorescens P-26 proteinase in terms of D-value was studied in whole milk, skim milk, whey and 0.05 mol l-1 phosphate buffer at 72.5, 130, 135, 140, 145 and 150 degrees C subsequent to its partial purification through (NH4)2 SO4 precipitation (45-65% saturation) and solvent fractionation with 1.0 to 2.0 volumes of isopropanol. The D-value was maximum for the proteinase at all temperatures when determined in whole milk (D150 = 0.088).