Kinetic modelling of the quality degradation of frozen watermelon tissue: effect of the osmotic dehydration as a pre-treatment

Watermelon pieces were submitted to osmotic pre-treatment in alternative osmotic solutions of glucose, oligofructose and a high dextrose equivalent (DE) maltodextrin, in order to evaluate the quality and assess the stabilisation accomplished during the subsequent frozen storage in a wide temperature range from -5 to -20 degrees C. Colour change and total lycopene content loss were kinetically studied, and their temperature dependence was modelled by the Arrhenius equation. Dehydrofrozen samples exhibited significantly improved stability, with the rates of colour change and total lycopene loss being reduced up to 70% and 38%, respectively, for osmotically pre-treated watermelon, compared with the untreated samples.