title: Increased hydrophobicity of carboxymethyl starch film by conjugation with zein.
abstract: A carboxymethyl starch (CMS) film was prepared by a process in which gelatinized CMS was dried, and subsequently treated with water-soluble carbodiimide in the presence of zein in 70% ethanol or 70% acetone to form acid-amide cross-linkages in order to increase the hydrophobicity of the surface of the film. A small amount of zein protein was found to be present on the surface of the zein-CMS conjugate (Zein-CMS) film, resulting in its insolubility in hot water, low water vapor permeability, and resistance to digestion with alpha-amylase and beta-amylase. Digestion of the Zein-CMS film with protease rendered the film readily water-soluble, suggesting conjugation with zein as an effective means of increasing the hydrophobicity of biodegradable starch-based articles.
authors.affiliation: Department of Applied Biological Sciences, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan. k-taka@cc.tuat.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Takahashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogata
authors.forename: Wen-Hong
authors.initials: WH
authors.lastname: Yang
authors.forename: Makoto
authors.initials: M
authors.lastname: Hattori
mesh_terms: D020341:Absorbable Implants; D000681:Amylases / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008567:Membranes, Artificial; D010539:Permeability; D012995:Solubility; D013213:Starch / Q000031:analogs & derivatives* / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015028:Zein / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D014867:Water; D013213:Starch; D015028:Zein; C034848:carboxymethyl starch; D000681:Amylases; D010450:Endopeptidases