title: Polishing and parboiling effect on the nutritional and technological properties of pigmented rice.
abstract: This study aims to evaluate the effects of polishing and parboiling on proximate composition, structure, phenolic compounds, antioxidant activity, cooking time and hardness of IAC-600 black rice cultivar and MPB-10 red rice lineage. Proximate analysis and light micrographs revealed higher migration of red rice proteins than black rice proteins to the endosperm as a result of parboiling. Parboiling reduced the ash content of red rice while no difference was determined in black rice. Gelatinized starch granules from both genotypes showed similar appearance. There was a decrease in relative crystallinity on both black and red rice subjected to parboiling, which was an indicative of crystallites disruption. Polishing removed more than 90% of free phenolics for both genotypes, while parboiling allowed the partial preservation of free phenolics content in polished rice. Parboiling induced an increase in the cooking time of red rice, but a decrease in the cooking time of black rice.
authors.affiliation: Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil; Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States.
authors.forename: Flávia Fernandes
authors.initials: FF
authors.lastname: Paiva
authors.affiliation: Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil; Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States. Electronic address: nathanvanier@hotmail.com.
authors.forename: Nathan Levien
authors.initials: NL
authors.lastname: Vanier
authors.affiliation: Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States.
authors.forename: Jose De J
authors.initials: Jde J
authors.lastname: Berrios
authors.affiliation: Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil.
authors.forename: Vânia Zanella
authors.initials: VZ
authors.lastname: Pinto
authors.affiliation: Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States.
authors.forename: Delilah
authors.initials: D
authors.lastname: Wood
authors.affiliation: Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States.
authors.forename: Tina
authors.initials: T
authors.lastname: Williams
authors.affiliation: Healthy Processed Foods Research Unit, WRRC, ARS, United States Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, United States.
authors.forename: James
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil.
authors.forename: Moacir Cardoso
authors.initials: MC
authors.lastname: Elias
mesh_terms: D003116:Color; D003296:Cooking; D005838:Genotype; D006244:Hardness; D006358:Hot Temperature; D012275:Oryza / Q000737:chemistry* / Q000235:genetics; D010636:Phenols / Q000032:analysis; D013213:Starch / Q000737:chemistry
chemical_list: D010636:Phenols; D013213:Starch
keywords: Black rice; Cooking quality; Free and bound phenolics; Proximate composition; Red rice; Structure