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The division of Color Space into ten zones, corresponding to the ten Munsell hues, allows a good reconstruction of surface reflectance spectra using just three eigenvectors, obtained by applying principal components analysis to the reflectance spectra of the Munsell Atlas specimens (model group), although the basis vectors obtained are different for each subspace. The use of the tristimulus values from each measured spectrum, calculated with the Illuminant D65 and the Standard Observer CIE64 to obtain the principal components necessary to reconstruct the spectrum, allows a very high degree of metamerism to be attained between the two spectra (measured and reconstructed). Furthermore, this method of calculating the principal components allows reconstruction of the spectra of specimens from other sample sets that differ from the model group used in the PCA. The colorimetric accuracy obtained in the new sample sets is similar to that obtained for the model group.

Since minimal processing of vegetables does not impede their capacity to react to external stimuli, this work sought to study the effect of lighting on minimally processed leek during storage. White and green cuts were processed separately and packaged using films with different permeability: a totally permeable PVC film and two P-Plus films: P-Plus 120 and P-Plus 90, with O 2 permeability of 8000 and 5000 cm 3 m )2 24 h )1 atm )1 at 25°C, respectively. All the packaged leek was stored at 4°C for more than 26 days in two different conditions: in complete darkness and in light. Lighting caused an increase in stomatal aperture and respiratory rate. Thus, the white cut achieved atmospheres with higher CO 2 (10%) and lower O 2 (12%) content than samples packed in the same film kept in the dark. The green cut saw respiratory activity compensated by photosynthesis, and the atmosphere composition remained similar to atmospheric conditions until day 18. Lighting also affected the colour, accelerating the changes in appearance. Exposure to light had a negative effect on the quality parameters.

BACKGROUND: The effect of lighting on minimally processed chard during storage was studied. To compare the influence of pigmentation on the behaviour of the vegetable when exposed to light, the white and green parts were processed separately. Four films with different permeabilities were tested.