Gormley et al. matched the quality of mushrooms to the average
L* value: L* > 86 represents good quality and L* > 80 corresponds to
fair quality (Gormley, 1975; Guillaume et al., 2010). The L* histogram
reported by the program Photoshop allows to easily determine
the percentage of pixels in the image with L* values higher
than any established threshold. Another histogramwas created that
shows how the portion of the image that keeps good quality
(L* > 80) decreases over time. The tendencies observed were
similar to the ones in L* value histogram being the test pouches
with metabisulphite/citric acid the most favourable ones to keep
the white colour of mushrooms after 4 and 8 days.