Is It Possible to Do a Reliable Assessment of Bergamot Colour in the Field with a Smartphone Camera?

Bergamot (Citrus bergamia, Risso et Poiteau) is a citrus fruit cultivated in a narrow coastal strip of about 150 km in the province of Reggio Calabria (southern Italy). It is used in various sectors, including medicine, cosmetics, perfumery and the food industry. Having regard to this, the purpose of this work is to present the intermediate results of an ongoing industrial doctoral thesis, in the framework of the National Operative Program PON Research and Innovation 2014–2020 funded by the Italian Ministry of University and Research (MUR). In particular, the paper deals with the assessment of bergamot fruit colour directly in the field. The first step was to take pictures of fruit at different stages of ripening using a smartphone coupled with a portable black chamber. Secondly, bergamot colour was measured in the laboratory using a Konica Minolta CM-700d portable spectrophotometer, which had been calibrated beforehand. The Citrus Colour Index (CCI) was then calculated for both methods. The results obtained in calculating the accuracy of the CCI showed that using the smartphone combined with the low-cost camera gave results equivalent to those of the spectrophotometer (R2 = 0.93).