Effects of acid-hydrolysis and hydroxypropylation on functional properties of sago starch.
In this study, sago starch was hydrolyzed by 0.14M HCl for 6, 12, 18, and 24h, and then modified by propylene oxide at a concentration of 0-30% (v/w). The effects of hydrolysis and etherification on molecular weight distribution, physicochemical, rheological, and thermal properties of dually modified starch were estimated. Acid hydrolysis of starch decreased the molecular weight of starch especially amylopectin, but hydroxypropylation had no effect on the molecular weight distribution. The degree of Molar substitution (DS) of hydroxypropylated starch after acid hydrolysis ranged from 0.007 to 0.15. Dually modified starch with a DS higher than 0.1 was completely soluble in cold water at up to 25% concentration of the starch. This study shows that hydroxypropylation and hydrolysis have synergistic effects unlike individual modifications. Dually modified sago starch can be applied to dip-molding for food and pharmaceutical processing because of its high solubility and low tendency for retrogradation.
Food Biopolymer Research Group, Food Science and Technology Department, Damghan Branch, Islamic Azad University, Damghan, Semnan, Iran.
Elham
E
Fouladi
Food Biopolymer Research Group, Food Science and Technology Department, Damghan Branch, Islamic Azad University, Damghan, Semnan, Iran. Electronic address: fstiau@gmail.com.
Abdorreza
A
Mohammadi Nafchi
D028023:Arecaceae / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D004852:Epoxy Compounds / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D006851:Hydrochloric Acid / Q000494:pharmacology*; D006868:Hydrolysis / Q000187:drug effects; D006900:Hydroxylation / Q000187:drug effects; D012995:Solubility; D013213:Starch / Q000737:chemistry*; D014783:Viscosity
D004852:Epoxy Compounds; D005782:Gels; D013213:Starch; D006851:Hydrochloric Acid; C009068:propylene oxide
Dual modification; Sago starch; Thermal properties