skin discoloration by different treatments. Maftoonazad and
Ramaswamy (2005) who studied postharvest shelf-life extension
of avocados using methyl cellulose-based coating have proven that
the changes in the greenness occurred at a much slower rate in
avocados coated with 3 g/L methyl cellulose in a water-ethyl
alcohol mixture (3:1) and 1.9 g/L glycerol. Ali et al. (2010) reported
that tomatoes coated with 15% or 20% gum arabic and 1%
glycerol monostearate remained green even after 20 days of storage.
Zambrano-Zaragoza et al. (2013) also stated that guavas coated
with 4 g/L xanthan gum and 60 g/L SLN (solid lipid nanoparticle)
showed a slower rate of color change.
Total color difference (DE), which is a combination of parameter
L*, a* and b* values, is a colorimetric parameter extensively used to
characterize the variation in color perception. A decrease in total
color difference was observed when limes coated with (i) 0.2%
xanthan gum & 1.50% extracted lignin from 40% (w/w) NaOH, (ii)
0.4% xanthan gum & 1.50% extracted lignin from 40% (w/w) NaOH
or (iii) 0.8% xanthan gum & 1.50% extracted lignin from 40% (w/w)