The coating solutions were prepared by completely gelatinizing 1, 1.5 and 2 g/100 mL starch slurry in water at 95 C for 30 min on a heating plate while stirring with a magnetic stirrer, followed by addition of glycerol (0.4, 0.5 and 0.6 mL) as plasticizer and further heating and mixing for 10 min for crosslinking to occur.