Image processing for the determination of jam browning kinetics

The production process of jam involves heat treatments that, in some conditions, can affect the quality of the product. In this paper the colour changes in apple and peach high quality ‘Extra Jam’ due to heat treatment were investigated using colour image processing techniques. Colour analysis was carried out measuring CIELAB parameters and evaluating the colour difference (ΔE) on the pictures acquired by a professional scanner. These data were compared with the colour coordinates obtained by a colorimeter. Two thermal treatments, 80°C and 90°C, were considered. Colour deterioration was described by a colour difference profile and then modelled by a first order kinetic. Image analysis technique provided more consistent data than colorimeter, resulting a very helpful tool for colour measurement on heterogeneous media as ‘Extra Jams’.