Submitted to: Cereal Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/10/2010
Publication Date: 1/4/2011
Citation: Guraya, H.S., Patindol, J.A. 2011. Storage stability of flour-blasted brown rice. Cereal Chemistry. 88(1):56-63. Interpretive Summary: Generally, instant or quick-cooking rice products are prepared by first hydrating and/or precooking raw rice followed by drying the treated rice to desired moisture content. These methods of instantization require significant amounts of water and energy, adding cost to the product and often affecting product quality. Moreover, most of these processes have been developed for white rice. Relatively few quick-cooking brown rice technologies have been developed. Because the bran layers contain most of the nutrients in the rice kernel, the development of quick-cooking brown rice products acceptable to the consumer would be highly desirable. We reduced the cooking time of brown rice by puncturing the water-resistant bran layers to produce microscopic holes. This would allow water to penetrate more quickly into the starchy endosperm of the kernel, resulting in faster cooking time. The process could be accomplished by bombarding brown rice with high-velocity, abrasive tiny particles. This would create microperforations (i.e., nicks, holes, or cuts) on the water resistant outer layer of brown rice. A sandblaster is typically used to remove rust from metal parts or to smooth the surface. We propelled brown rice flour against the brown rice with pressurized air in the sandblaster, which created microperforations. We stored the brown rice for 10 months and studied the shelf stability.
Technical Abstract: Brown rice was blasted with rice flour rather than sand in a sand blaster to make microscopic nicks and cuts so that water can easily penetrate into the brown rice endosperm and cook the rice in a shorter time. The flour-blasted American Basmati brown rice, long grain brown rice, and parboiled long grain brown rice samples were stored in Ziploc® bags under atmospheric conditions and in vacuum packaged bags, and were periodically tested for over 10 months for changes in water absorption, free fatty acids (FFA), peroxide value (POV), viscosity changes of flour using Rapid Visco Analyzer (RVA), and texture of whole cooked kernal using Texture Analyzer during cooking. Flour-blasted rice absorbed less water but needed less cooking time than its non flour-blasted counterpart. There was an increase in FFA, POV, Peak Viscosity (PV), final viscosity (FV), breakdown viscosity (BD), and setback viscosity (SB) during storage of flour-blasted brown rice for 300 days, but no change was observed in texture (hardness, gumminess) and water absorption. The combined coefficient of correlation (including all types of rice) between FFA and FV is 0.86 and between FFA and SB is 0.90 at p<0.0001. Other correlations also occur in the data, which could be used to model rancidity and develop standard methods, which could then be used by the rice industry to monitor rancidity.