title: Impact of structural characteristics on starch digestibility of cooked rice.
abstract: To examine the impact of structural characteristics of cooked rice grains on their starch digestibility, a simulated in vitro gastro-small intestinal digestion technique was applied to intact and homogenised cooked rice samples. The starch hydrolysis percentage increased during simulated small intestinal digestion, in which approximately 65% and 24% of the starch was hydrolysed within the first 5min, for homogenised and intact cooked rice, respectively. The kinetic constant of homogenised cooked rice, which was regarded as an estimated digestion rate, was ∼8 times higher than the intact cooked rice. The homogenised and intact samples were also examined for any microstructural changes occurring during the in vitro digestion process using fluorescent and scanning electron microscopy. In the intact samples, the aleurone layers of the endosperm remained as thin-film like layers during in vitro digestion and thus may be regarded as less digestible materials that influence cooked rice digestibility.
authors.affiliation: Graduate School of Horticulture, Chiba University, 648, Matsudo, Matsudo 271-8510, Japan. Electronic address: m-tamura@cc.utsunomiya-u.ac.jp.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Tamura
authors.affiliation: Riddet Institute, Massey University, PB 11 222, Palmerston North 4442, New Zealand. Electronic address: J.X.Singh@massey.ac.nz.
authors.forename: Jaspreet
authors.initials: J
authors.lastname: Singh
authors.affiliation: Riddet Institute, Massey University, PB 11 222, Palmerston North 4442, New Zealand. Electronic address: L.Kaur@massey.ac.nz.
authors.forename: Lovedeep
authors.initials: L
authors.lastname: Kaur
authors.affiliation: Graduate School of Horticulture, Chiba University, 648, Matsudo, Matsudo 271-8510, Japan. Electronic address: ogwy@faculty.chiba-u.jp.
authors.forename: Yukiharu
authors.initials: Y
authors.lastname: Ogawa
mesh_terms: D003296:Cooking; D056625:Endosperm / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D012275:Oryza / Q000737:chemistry*; D010316:Particle Size; D013213:Starch / Q000737:chemistry*
chemical_list: D013213:Starch
keywords: Aleurone layer; Cell wall; Cooked rice grain; In vitro starch digestion; Tissue structure