title: Chemical force mapping of phosphate and carbon on acid-modified tapioca starch surface.
abstract: Surface chemical microstructure of hydrochloric acid hydrolyzed tapioca starch producing different amylose:amylopectin (Am:Ap) ratios were studied with scanning chemical force microscopy (CFM). The chemical force probes were functionalized of two types with -OH (phosphate specific) and -CH3 (carbon specific). Lateral force trace-minus-retrace (TMR) images from -OH and -CH3 probes revealed changes in the phosphate domains and the carbon backbone for the varying acid hydrolyzed tapioca starch compared to that of the native tapioca starch. Scanning electron micrographs (SEM) showed different degree of the granule surface disruption before and after hydrolysis. The exterior structures of the acid hydrolyzed starch granules were chemically investigated with CFM to study the relationships of the surface molecular structures and the Am:Ap ratios.
authors.affiliation: Institute for Innovation and Development of Learning Process, Department of Physics, Mahidol University, Salaya Campus, Phuttamonthon Sai 4 Rd., Nakhon Pathom 73170, Thailand.
authors.forename: Karntarat
authors.initials: K
authors.lastname: Wuttisela
authors.forename: Wannapong
authors.initials: W
authors.lastname: Triampo
authors.forename: Darapond
authors.initials: D
authors.lastname: Triampo
mesh_terms: D002244:Carbon / Q000737:chemistry*; D006851:Hydrochloric Acid; D006868:Hydrolysis; D002365:Manihot / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry*; D013213:Starch / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D010710:Phosphates; D002244:Carbon; D013213:Starch; D006851:Hydrochloric Acid