title: The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).
abstract: The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes.
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia; Kenya Agricultural Research Institute, Nairobi, Kenya.
authors.forename: Peterson W
authors.initials: PW
authors.lastname: Wambugu
authors.affiliation: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia; Whistler Center for Carbohydrate Research and Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Alex Chi
authors.initials: AC
authors.lastname: Wu
authors.affiliation: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Henry
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia. Electronic address: b.gilbert@uq.edu.au.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gilbert
mesh_terms: D000383:Agriculture; D000688:Amylose / Q000737:chemistry; D002850:Chromatography, Gel; D005780:Gelatin / Q000737:chemistry; D008962:Models, Theoretical; D008970:Molecular Weight; D012275:Oryza / Q000737:chemistry*; D013213:Starch / Q000096:biosynthesis* / Q000737:chemistry*
chemical_list: D005780:Gelatin; D013213:Starch; D000688:Amylose
keywords: African rice; Biosynthesis enzymes; Gelatinization; Molecular structure; Starch