Total starch (TS) was determined by the method of Goñi, García,and Saura-Calixto (1997). In brief, 50 mg of sample were dispersed in 2 M KOH (30 min) to disperse all starch fractions; then samples were incubated with amyloglucosidase (Boehringer, No. 102857,60°C, 45 min, pH 4.75), and glucose was determined using the glucose oxidase assay GOD-POD. TS was calculated as released glucose(mg)คูณ0.9.