The Effect of Murashi as a Factor Controlling Rice Cooking

Research Project

Project/Area Number	62580071
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	家政学
Research Institution	Shizuoka Women's College
Principal Investigator	KAINUMA Yasuko Shizuoka Women's College, 食物栄養学科, 助教授 (90071000)
Co-Investigator(Kenkyū-buntansha)	江間章子静岡女子短期大学, 食物栄養学科, 助手伊藤千恵子跡見学園短期大学, 教授 (90141176) ITO Chieko Atomi Gakuen Junior College EMA Shoko Shizuoka Women's College
Project Period (FY)	1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
Keywords	Effect of Murashi / Weight Change / Degree of Gelatinization / Texture / Microscopic Observation / 水分の状態
Research Abstract	Murashi(post-heating)is thought of the necessary operation for rice cooking process. We studied about the effect of murashi for cooked rice quality. We tested the physical and chemical characteristics,and sensory tests for the different murashi time (0,5,10,15 min.). The results and consideration were as follows. 1) Murashi is necessary to gelatinized satisgactory in the center of cooked rice granule. 2) The dehybration rate by infrared moisture meter is smaoo in the cooked rice,carrying out the murashi. We considered the moisture in cooked rice became stable state gradually by murashi. 3) In microscopic observationmit was obserbed the extraneous matters or crumble parts on the surface tissue of cooked rice,by murashi. 4) The washing water of cooked rice surface was analyzed by paperchromatography. It was showed continuous spot: glucose(G_1),maltose(G_2), maltotriose(G_3),maltotetraose(G_4),maltopentaose (G_5), maltohexaose(G_6),and G_7-origin. The rate of sugar in the spots of G_1,G_3 and G_4 were comparativery high just after turnning off the gas. But,G_6,G_7-origin and origin,which were high molecular weight fraction,were remarkably found by murashi. The sugar composition in high molecular fraction is intended to investigate by high performance liquid chromatography. 5) Whili murashi was doing,the expznsion of cooked rice granule was advanced,and the granular size of each parts was made uniform. 6) The texture of cooked rice had low hardness,high adnesivenss and cohesiveness by murashi.