Swelling and Gelatinization of Oat Starches RICHARD

A comparison was made between the structure and physicochemical properties of starches extracted from five normal and one naked cultivar of oat. There was little difference in the molecular size or polydispersity of the native amylose and amylopectin determined by gel permeation chromatography (GPC), or in the unit chain distribution of isoamylasedebranched amylopectin, where three peaks were resolved at modal degree of polymerization of 15, 23, and 46. Apparent, total, and A-amylose (difference between apparent and total amylose due to lipid complexing) contents ranged from 19.7 to 22.0%, 27.5 to 29.8%, and 7.1 to 8.1, respectively, with lipid content, as fatty acid methyl esters, ranging from 0.66 to 0.75% on a dry basis and comprising the following fatty acids: 46.6% C16; 2.1% C18; 15.0% C18:1; 35.3% C18:2, and 0.7% C18:3. The naked oat starch had the lowest lipid content and A-amylose. Lintner type solubilization in 2M HCl (six days of incubation at 35 C) ranged from 56.6 to 60.0% of the original dry Cx-glucan. The 80'C swelling factor corresponding to postgelatinization swelling (determined by a