Investigation of Relationship between Variation of Colour Change of Fruits with their Shelf-Life and other Physical Properties

Abstract

The relation between diffused reflectance (in spatial and in spectral domains), soluble solid content and firmness of "Mauritius" variety of pineapple (Ananas comosus) grown in Labuduwa farm, Galle, Sri Lanka together with the shelf-life have been studied for estimating the physiological maturity of them. It is found that there is no significant variation in the firmness with the shelf-life. The soluble solid content shows a linear relationship with respect the shelf-life for this sample of size ten with a coefficient of determinant (R2) of 0.87. Diffused reflectance measured using an RGB web camera with the help of two linear polarisers and converted into the spherical coordinate system and two-dimensional histograms were plotted considering the zenith and azimuth angles. It is found that the peak of the two-dimensional histograms follows similar paths and converged to the same region for all pineapple in the sample with the shelf life. Also, it is found that the average colour (by considering each pixel) ratio of red to green show a linear relationship with the soluble solid content (R2=0.1255) and shelf life (R2=0.6929).