title: Effects of ripening temperature on starch structure and gelatinization, pasting, and cooking properties in rice (Oryza sativa).
abstract: The effect of ripening temperature on rice (Oryza sativa) grain quality was evaluated by assessing starch structure and gelatinization, pasting, and cooking properties. As the ripening temperature increased, the amylose content and number of short amylopectin chains decreased, whereas intermediate amylopectin chains increased, resulting in higher gelatinization temperatures and enthalpy in the starch. These results suggested that an increase in cooking temperature and time would be required for rice grown at higher temperatures. A high ripening temperature increased the peak, trough, and final viscosities and decreased the setback due to the reduction in amylose and the increase in long amylopectin chains. With regard to starch crystallinity and amylopectin molecular structure, the highest branches and compactness were observed at 28/20 °C. Rice that was grown at temperatures above 28/20 °C showed a deterioration of cooking quality and a tendency toward decreased palatability in sensory tests.
authors.affiliation: †Rice Research Division, National Institute of Crop Science, Rural Development Administration, Suwon 441-707, Korea.
authors.forename: Areum
authors.initials: A
authors.lastname: Chun
authors.affiliation: §Department of Plant Science, Seoul National University, Seoul 151-921, Korea.
authors.forename: Ho-Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: #Department of Food Science, Purdue University, West Lafayette, Indiana 47907, United States.
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Hamaker
authors.affiliation: #Department of Food Science, Purdue University, West Lafayette, Indiana 47907, United States.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Janaswamy
mesh_terms: D003296:Cooking; D006358:Hot Temperature; D015394:Molecular Structure; D012275:Oryza / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*
chemical_list: D013213:Starch
keywords: Oryza sativa; amylopectin; amylose; cooking; gelatinization; pasting; rice; starch; temperature