Non-destructive determination of the optimum harvest time of the sweet cherry cultivar ‘Cashmere’ through CIELab colour coordinates and the principal component analysis (PCA)

A principal components analysis (PCA) carried out on the L*, a* and b* color coordinates, allows a good discrimination among maturity stages of the ‘Cashmere’ sweet cherry cultivar.
Physical-chemical parameters were determined by conventional destructive methods that were used as a reference to compare with statistically treated optical data.
The study was carried out during two consecutive campaigns 2010 and 2011. Samples were taken at optimum harvest time following the criteria of firmness, soluble carbohydrates and expert visual estimation of color.
In the first season, two other samples of 200 fruits each, were picked at random in the plot from several trees, a week before and a week after the estimated optimal date.
In 2011, sampling was made as in 2010 but timing was as follows: two days before harvest, at harvest and 2 and 4 days after.
In both seasons, a simple representation of fruit color in the a* b* space of the whole set of samples in a single year, did not permit differentiation of fruits on a maturity stage basis.
However, a principal component analysis including not only a* and b* but also the luminosity L*, allowed the classification of fruits according their ripeness using only the first component PC1. This work demonstrates that a simple colorimeter can be a suitable alternative to destructive methods to determine the optimum harvest time and also may permit the prediction of the shelf life of this commodity (very short indeed, 1 week approximately).

VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits – Ethical and Technological Issues

V. Lafuente, J. Val, A.I. Negueruela

cherry, colorimetry, fruit maturity, PCA, statistics

https://doi.org/10.17660/ActaHortic.2018.1194.157