Cucumber keeping quality predictions: a phenotyping tool.

Minor-thesis abstract (submitted 25 August 2015): Cucumber appearance is the primary criteria for consumers to assess quality and in this process colour plays a very important role. A model based on physiological mechanism to predict keeping quality of cucumbers has been developed.

This study goes further to detect the possibility of predicting keeping quality based on initial colour measurement, and to test whether the RGB value received from a 3CCD digital camera is related to the chlorophyll concentration measurement.
Three batches of cucumbers harvested on different time were used in this study. The 1st and 3rd batches of cucumbers were stored at 20˚C and 2nd batch was stored at 15, 20 and 25 ˚C to calibrate the colour model. Colour data is expressed as 1/G*100 and 1/R*100. The keeping quality determined by the time that 75% of all cucumbers in one cultivar has an acceptable colour (1/G*100>1). Three cucumbers of each cultivar in 3rd batch are used to determine the chlorophyll concentration by spectrophotometric measurements.

Results display that the keeping quality is not possible to predict by only initial colour measurement. Comparing the colour measurement data with CHL concentration measurement, a good link has been found between CHL a, CHL b and 1/G*100. For further keeping quality researches new models based on the CHL concentration can be developed.