|Wood, Delilah - De|
Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: 12/13/2002
Publication Date: 1/13/2003
Citation: Wood, D.F., Ogawa, Y., Bailey, D.A., Mckenzie, K., Mcclung, A.M., Ibanez-Carranza, A., Shoemaker, C.F. 2002. Rice microstructure - comparing cultivars. In: John P. Cherry and Attila E. Pavlath, eds., Proceedings of the United States/Japan Natural Resources Protein Panel 31st Annual Syposium. BB-1/BB-7. Interpretive Summary:
Technical Abstract: The microstructures of short, medium, long and waxy grain rices were compared for microstructural characteristics using scanning electron and light microscopies. The cultivars in this study included three short grain (Akitakamachi, Koshihikari and S102); three medium grain (Bengal, M202 and M401); four long grain (L203, L204, L205 and Cypress); and two waxy-types (Calmochi¿101 and Kogane¿mochi). Raw and milled kernels and flours from each cultivar were studied over two to three harvest seasons. Many more similarities than differences were found. The most obvious difference between the waxy rice and the other grains was found in the starch granules where waxy type starch stained purple (characteristic of amylopectin and indicating little or no amylose) and non-waxy starch stained blue (characteristic of amylose) with iodine. Waxy starch also contained cavities inside the individual starch granules, perhaps weakening the starch granule structure. Differences in protein distribution and the ratio of the two types of starchy endosperm protein bodies, Type I and Type II, were also apparent between the cultivars. The Type I protein body is less digestible than the Type II, therefore, differences in the ratio of protein body types could have implications in digestibility of the different cultivars.