EFFECT OF TEMPERATURE AND SOLUBLE SOLIDS CONTENT ON NONENZYMATIC BROWNING KINETICS FOR CLARIFIED APPLE JUICES

The kinetics of nonenzymatic browning at different temperatures (60, 7 0, 80, 85, 90, and 95 degrees C) of clarified apple juices, for the va rieties Granny Smith and Jonagold with different soluble solids conten t were studied. The browning was followed by the variation of absorban ce at 420 nm (A(420)) Browning was described by a zero-order kinetical model. The effect of temperature on kinetic constants can be describe d by an Arrhenius-type equation. The effect of soluble solids content on the Arrhenius equation parameters are described by a power-law equa tion. The Granny Smith juices present a nonenzymatic browning which wa s more pronounced than Jonagold juices.