Visual colour degradation of tomato puree and strawberry juice at three different pH values (2.5, 3.7 and 5) during thermal (100–140°C, 0–120min) and high pressure thermal (300–700MPa, 60min, 65°C) treatments were studied. Hunter colour scale values L ∗ , a ∗ and b ∗ of each treated sample were measured. Results indicated that the thermal degradation of tomato and strawberry colour followed first order kinetics (fractional conversion model). The L ∗ a ∗ /b ∗ parameter combination described best the colour change of all samples. The activation energies for the different material were 129.12, 181.40, 162.60, 85.77kJ/mol×10 −2 for tomato puree, strawberry at pH 2.5, strawberry at pH 3.7, and strawberry at pH 5, respectively. Colour of strawberry at pH 5 was less heat stable but the degradation constants were less sensitive to temperature changes.No colour degradation of tomato appeared under combined thermal and high pressure treatment; a maximum increase of 8.8% in L ∗ a ∗ /b ∗ parameter was found for strawberry samples (pH 5).