title: Dilatometric measurement of the partial molar volume of water sorbed to durum wheat flour.
abstract: Moisture sorption isotherms were measured at 25 °C for untreated, dry-heated and pre-gelatinized durum wheat flour samples. The isotherms could be expressed by the Guggenheim-Anderson-de Boer equation. The amount of water sorbed to the untreated flour was highest for low water activity, with water sorbed to the pre-gelatinized and dry-heated flour samples following. The dry-heated and pregelatinized flour samples exhibited the same dependence of the moisture content on the partial molar volume of water at 25 °C as the untreated flour. The partial molar volume of water was ca. 9 cm(3)/mol at a moisture content of 0.03 kg-H2O/kg-d.m. The volume increased with increasing moisture content, and reached a constant value of ca. 17.5 cm(3)/mol at a moisture content of 0.2 kg-H2O/kg-d.m. or higher.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Takenobu
authors.initials: T
authors.lastname: Ogawa
authors.forename: Shuji
authors.initials: S
authors.lastname: Adachi
mesh_terms: D000327:Adsorption; D005433:Flour; D013696:Temperature; D014908:Triticum / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water