Tomatoes coated with rice starch-based edible coating formulation containing coconut oil and tea leaf
extract were studied for the effect of coating on biochemical changes during storage for 20 days. Addition
of lipid and tea leaf antioxidant extract in starch/glycerol coating solution improved the surface integrity
of films but decreased the solubility and stability of the films and coating solutions. Starch retrogradation
was reduced and amylose-lipid complexation occurred on addition of coconut oil as suggested by
Differential Scanning Calorimetry. After 20 days of storage, weight loss was 1.78% less for starch/glycerol/
lipid (S/G/L) coated and 3.53% less for starch/glycerol/lipid/antioxidant (S/G/L/A) coated tomatoes as
compared to control. Titratable acidity was 0.262 0.007% and 0.337 0.003% and pH was 4.62 0.013
and 4.27 0.015 for control and S/G/L/A coated tomatoes, respectively. TSS (Brix) increased with storage
in all samples but S/G/L/A coated tomatoes exhibited 0.5 Brix less TSS than the control. Reducing sugars
and ascorbic acid increased with storage initially and thereafter decreased later on with control showing
maximum fall and S/G/L/A and S/G/L recording lowest fall, in that order. Coconut oil and tea leaf extract
in the edible coating clearly delayed ripening effects on tomatoes. The coconut oil and tea extract also
exhibited microbe-barrier property.