Cereal Chem 64:394-399   |  VIEW ARTICLE

Differential Scanning Calorimetry of Oat Starch Pastes.

D. Paton. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

Oat starch (variety Sentinel) was examined by differential scanning calorimetry over a range of moisture contents. Two endotherms were observed, one around 66 C and a second at 102-104 C. Washing the granules at room temperature with n-propanol-water (3:1, v/v) did not alter the thermogram, whereas refluxing in the same solvent reduced the endotherm at 66 C and completely eliminated the one at 102-104 C. This result is evidence for the existence of amylose-lipid complexation in oat starch. Treatment of the data according to the Flory-Huggins equations showed that oat starch exhibits a higher temperature of melting of most perfect starch crystallites (Tmo) and a slightly lower enthalpy of fusion of the repeating glucose unit (delta H micron) when compared with other cereal starches. The amylose-lipid endotherm exhibits a slightly lower value for Tmo but a higher value for delta H micron when compared to corresponding data for other starches. Storage studies conducted with 30% w/w oat starch pastes showed that the rate of retrogradation was reduced by around 50% and that this was a function of the bound lipid. These results are discussed in terms of providing further explanation for previously observed anomalies in oat starch paste and gel behavior.