title: Functional, thermal and molecular behaviours of ozone-oxidised cocoyam and yam starches.
abstract: Ozone-oxidised starches were prepared from the native starches isolated from white and red cocoyam, and white and yellow yam cultivars. The native and oxidised starches were evaluated for functional, thermal and molecular properties. The correlations between the amount of reacted ozone and carbonyl and carboxyl contents of the starches were positive, as ozone generation time (OGT) increased. Significant differences were obtained in terms of swelling power, solubility, pasting properties and textural properties of the native starches upon oxidation. The DSC data showed lower transition temperatures and enthalpies for retrograded gels compared to the gelatinized gels of the same starch types. The native starches showed CB-type XRD patterns while the oxidised starches resembled the CA-type pattern. As amylose content increased, amylopectin contents of the starches decreased upon oxidation. Similarly, an increase in Mw values were observed with a corresponding decrease in Mn values upon oxidation.
authors.affiliation: Food Biopolymer Science Research Group, School of Industrial Technology, Universiti Sains Malaysia (USM), Malaysia; Chemistry Department, The Federal University of Technology, Akure, Nigeria. folabeye@yahoo.com
authors.forename: Abraham Olasupo
authors.initials: AO
authors.lastname: Oladebeye
authors.forename: Aladesanmi Augustine
authors.initials: AA
authors.lastname: Oshodi
authors.forename: Isiaka Adekunle
authors.initials: IA
authors.lastname: Amoo
authors.forename: Alias Abd
authors.initials: AA
authors.lastname: Karim
mesh_terms: D027742:Dioscorea / Q000737:chemistry* / Q000145:classification; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D012995:Solubility; D013213:Starch / Q000737:chemistry*; D044366:Transition Temperature
chemical_list: D010126:Ozone; D013213:Starch