Rice breeders, producers and processors know that texture is as important as taste to rice consumers. Conventional methods of evaluating this quality involve expensive and time-consuming taste-testing panels.
Jean-Francois Meullenet, University of Arkansas Division of Agriculture food scientist, has developed a quick and relatively inexpensive instrumental method to evaluate cooked rice quality.
“I wanted to develop an instrumental method breeders could use to evaluate advanced breeding lines for quality,” Meullenet said. “Researchers can also use this method to determine how storage duration and drying temperatures affect rice quality.”
He said the characteristics that consumers perceive as texture are hardness and stickiness of the rice. The instrument applies measured pressure to a small sample of cooked rice to measure hardness of the kernel and the cohesiveness of its mass. When it pulls back from the sample, it measures its stickiness. The results are displayed on a computer screen for immediate analysis. Meullenet said one of the benefits of the method is that it requires only a small sample.
“Breeders don't have large quantities of their breeding lines that they can sacrifice for food texture and sensory analysis,” he said. “We can get accurate data with only 3 grams of rice.”
Meullenet is collaborating with UA food chemists Ya-Jane Wang and Navam Hettiarachchy to correlate compositions of starch and proteins with texture characteristics. He is also working with UA food scientists Terry Howell and Terry Siebenmorgen to determine how the interactions of chemical composition with storage and drying affect rice quality.
“If we can identify what chemically makes up desirable texture, then scientists can use biotechnology to control the genetic variables that affect rice quality,” he said. “For example, we may be able to remove or suppress expression of enzymes that lower quality during storage.”
Fred Miller is science editor for the Arkansas Agricultural Experiment Station.