Kinetics Of Colour Change Of Raspberry, Sweet (Prunus Avium) And Sour (Prunus Cerasus) Cherries Preserves Packed In Glass Containers: Light And Room Temperature Effects

This work studied the kinetics of colour change in preserves exposed to different lighting conditions (light & darkness), at constant temperature, as well as stored at several temperatures. In all the preserves and treatments, the colour diminished noticeably during the first 90 days of storage to remain constant from then on. The kinetics of colour change was evaluated using the concept of fractional conversion, and a first-order kinetics was found in relation to both the effect of lighting conditions and temperature. The corresponding reaction rate constants were determined by regression analysis of the experimental data. For samples stored at different lighting conditions, the resulting constants of the different preserves were not alike: constants were higher in samples kept in the presence of light than corresponding samples stored in the dark.