This paper presents the content changes in the Chemical Oxygen Demand (COD) solubilised in hydrolisates obtained from thermally disintegrated municipal waste biofractions. A series of tests related to biowaste undergoing thermal treatment at the following temperatures: 55, 75, 95, 115, 135, 155 and 175°C were conducted for 0.5, 1 and 2 hours. The highest increase in COD solid fraction solubilisation (238%) was observed for the samples disintegrated at 175°C for 2 hours. The values of the reaction rate coefficient k20 = 0.6 d-1 and temperature coefficient θ = 1.023 were determined. Statistical analysis of the multiple regression (correlation coefficient R = 0.89) showed that the temperature has a greater impact on COD solid fraction solubilisation - determined β = 0.66. The multiple correlation coefficient for the treatment time was β = 0.61.