A) Different granulation levels of citrus fruits. A carpel from each spherical carpel was chosen by quartering. The granulation was assessed by measuring the extent of dry area on each carpel and was determined as: Not dry, level 0; less than 10%, level 1; 10–25% dry, level 2; 25–50%, level 3; more than 50%, level 4. (B) Lignin contents vary in different levels of citrus granulation. The letter a–e in the graph showed the significant differences at P < 0.05