Rice varieties with similar amylose content differ in starch digestibility and glycemic response in humans

• Published in: The American journal of clinical nutrition Vol. 54; no. 5; pp. 871 - 877
• Main Authors: Panlasigui, LN, Thompson, LU, Juliano, BO, Perez, CM, Yiu, SH, Greenberg, GR
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01-11-1991; American Society for Clinical Nutrition
• Subjects: Adult; ADULTE; ADULTOS; ALMIDON; AMIDON; AMILOSA; AMYLOSE; Amylose - analysis; ARROZ; Biological and medical sciences; Blood Glucose - analysis; blood glucose and insulin; Carbohydrate Metabolism; Cereal and baking product industries; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; Cooking; DIGESTION; Female; Food industries; Fundamental and applied biological sciences. Psychology; GLICEMIA; GLYCEMIE; High-amylose rice; Humans; Insulin - blood; INSULINA; INSULINE; Male; Oryza - chemistry; PLASMA SANGUIN; PLASMA SANGUINEO; PROPIEDADES FISICO-QUIMICAS; PROPRIETE PHYSICOCHIMIQUE; RIZ; Starch - metabolism; starch digestibility; starch-gel characteristics; VARIEDADES; VARIETE; Water; High-amylose rice; starch-gel characteristics; blood glucose and insulin; starch digestibility; Human; Pancreatic hormone; Cooking; Starch; Aminoacid derivative hormone; Glucose; Metabolism; In vitro; Insulin; In vivo; Amylose; Carbohydrate; Hormonal investigation; Comparative study; Glycemia; Digestibility; Rice
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/54.5.871

Three high-amylose rice varieties, IR42, IR36, and IR62, with similar chemical composition including amylose content (26.7–27.0%), were cooked under the same conditions and tested for in vitro digestibility as well as blood glucose and insulin responses in healthy human volunteers. The starch-digestion rate and the glycemic and insulin responses were the highest in IR42, followed by IR36 and, then, IR62. The differences were not due to unabsorbed carbohydrate but were related to their physicochemical properties, such as gelatinization temperature, minimum cooking time, amylograph consistency, and volume expansion upon cooking. When the three varieties were cooked for their minimum cooking time, they had the same degree of gelatinization and their starch-digestion rates and glycemic responses were similar. We conclude that amylose content alone is not a good predictor of starch-digestion rate or glycemic response. Rice varieties with similar high-amylose contents can differ in physicochemical (gelatinization) properties and this, in turn, can influence starch digestibility and blood glucose response.