It was taken an amount of 100 lL and added 2 ml from the anthrone solution (0.2 g anthrone and 100 ml sulfuric acid), heated in bain-marie for 8 min and then it was realized a reading in a spectrophotometer at 620 nm (Yemn & Willis, 1954); the amount of starch (%) was determined from 2 grams of pulp diluted in 50 ml of water centrifuged at 10,000 rpm for 10 min, in three washes with the centrifugation residues extracted through hydrolysis under reflux
(HCl 37% P.A.) for 2 h, followed by neutralization with a 20% sodium carbonate.