The colour change in concentrated apple, peach and plum pulp due to extended heat treatment was investigated. Colour differences (Delta E) and Hunter L parameters were used to estimate the severity of damage during heating of the fruit pulp at 56, 66, 80 and 94 degrees C for 700 min. The results indicate apparent first-order kinetics. Hunter a and b and CIE x and y parameters provided information on changes in chromatic attributes after severe heat treatment. The analysis of darn concerning the rate of colour deterioration in concentrated fruit pulps as a function of temperature suggests that more that one mechanism is involved.