The colour change in fruit corresponds to a fall in chlorophyll and
an increase in carotenoid synthesis (Pretel, Serrano, Amoros,
Riquelme, & Romojaro, 1995), reflecting the transformation of chloroplasts
to chromoplasts. The L values in both uncoated and coated
tomatoes sharply decreased during the initial maturation on storage
till 8th day, after which it again increased. For control samples, this
increase continued till the end of the storage period while for the
coated samples, there occurred a further little drop after the 16th day.
The a values increased with storage for all the samples almost
uniformly with time with S/G/L and S/G/L/A coatings restricting the
increase. The b values, contrary to the L values, showed an initial
increase till the 8th day followed by a fall upto almost the initial levels
on the 20th day. The a values representing the change from green to
red ( to þ) clearly indicated that antioxidants in the coating had
definitely minimized the accumulation of carotenoid compounds
(especially lycopene) in the tomatoes delaying the colour change on
storage. The S/G/L/A coating can be used on tomatoes to retard
ripening and reduce post harvest loss (Table 2).