  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
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Comparison of rice flour quality of Calmochi-101, Koshihikari, M-202 and L-204 from 1996 to 1999. A. M. IBAŅEZ-CARRANZA (1), J. J. Renner-Nantz (1), K. S. McKenzie (2), W. H. Yokoyama (3), and C. F. Shoemaker (1). (1) Department of Food Science & Technology, University of California, Davis, CA; (2) California Cooperative Rice Research Foundation, Rice Experiment Station, Biggs, CA; and (3) USDA, ARS, Western Regional Research Center, Albany, CA.
Environmental factors affect rice starch properties and consequently the cooking and eating qualities of milled rice. The objective of this work therefore was to quantify the effect of crop year on the physicochemical characteristics of California waxy (Calmochi-101), short (Koshihikari), medium (M-202) and long (L-204) rice flours. Viscoamylographic profiles, debranched starch molar mass and true amylose, protein and total fat content were determined using flour from four rice varieties grown in California from 1996 to 1999. The viscoamylographic profiles of 8% rice flours slurries were determined by a controlled stress rheometer with cone and plate fixture. The shear rate was held at 200 s(-1). Molar mass for iso-amylase debranched flours was determined using High Performance Liquid Chromatography with Multi-Angle Laser Light Scattering and Refractive Index Detector in tandem (HPLC-MALLS-RI). The viscoamylographic profile, pasting and gelatinization temperature were characteristic for each rice flour type. The Calmochi-101 flour exhibited a unique viscosity profile compared to the other samples. Peak viscosity, cooking viscosity at 95°C and final viscosity after cooling at 50°C were different for the same rice variety flour during the study years. True amylose content was also characteristic for each rice variety. Protein content ranged from 4.2 to 6.6. Total fat content ranged from 0.37 to 1.44. Studying the relationship between rice starch properties and rice starch pasting properties during several years will let to really characterize a rice variety.
Copyright 2001
The American Association of Cereal Chemists