Proceedings of the International Conference “Environmentally friendly and safe
technologies for quality of fruit and vegetables”, held in Universidade do Algarve, Faro,
Portugal, on January 14-16, 2009. This Conference was a join activity with COST Action 924.The colour of apples (flesh colour or skin colour) was assessed using the same individual apples repeatedly
in time at three different locations, in several seasons for five different cultivars. Two experiments were
conducted in the orchard, one experiment during postharvest storage. The same logistic model was applied
to analyse the data, separate for each location and cultivar. Non linear mixed effects regression analysis
allows to extract not only information on the kinetic parameters like reaction rate constant and potential
greenness, but also on the variation present in the data. The rate constant of the decolouration process was
found to be largely the same for all combinations (with one exception). The variation in biological shift factor,
as an expression for maturity, seems to be independent of orchard location and only slightly dependent
on orchard management procedures. The main differences observed are in the potential greenness of
the apples (colmin) that vary considerably between successive seasons and between cultivars. The applied
technology provides the necessary tools to analyse the effects of season and orchard management, for all
locations in the study. It opens wide alleys to investigate more dedicated the effects of weather, season,
management and orchard location in growing apples with a constant quality (colour) over the seasons,
locations and management procedures
