Abstract

The starches were statistically different (p < 0.05) in their protein, ash, fat, phosphorus, amylose and amylopectin content. The amylose/amylopectin ratios in corn, potato and rice starches were 0.389, 0.282 and 0.220, respectively. The phosphorus content in the same order of starches was: 0.15 ± 0.01; 0.80 ± 0.02 and 0.95 ± 0.02 g/kg, respectively. The chemical composition of the different starches, and specifically its amylose and amylopectin content, its phosphorus content and the way it is bound to the starch molecule, affect the functional properties like the viscosity of gels and the enzymatic hydrolysis rate of these molecules. The rice starch is easily hydrolyzed by the α-amylase enzyme from Aspergillus oryzae and therefore, it required less time to obtain maltodextrin by enzymatic hydrolysis from rice starch compared with those from corn or potato starch. Under saturation conditions of the enzyme, the dextrose equivalent content was proportional to the hydrolysis time, regardless of the starting starch source.

Key words: Starch, maltodextrins, dextrose equivalent, amylose, amylopectin.

Abbreviation

ADP, Average degree of polymerization; GRAS, generally recognized as safe; FDA, food and drug administration; DRS, direct reducing sugars; TRS, total reducing sugars; DE, dextrose equivalents; DB, dry basis; min, minutes.