Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/19/2018
Publication Date: 10/16/2018
Citation: Chen, M., McClung, A.M., Tabien, R.E. 2018. Effects of growing environment and cooking methods on resistant starch content of high amylose rice varieties. 37th Rice Technical Working Group Meeting Proceedings, February 19-22, 2018,Long Beach, California. p 160-161. Electronic Publication.
Technical Abstract: Resistant starch (RS), a type of fermentable dietary fiber, has potential to improve colon health and decrease cardiovascular disease risk factors. It is defined as the fraction of the starch and the products of starch degradation that resist digestion in the small intestines of healthy humans and is partially or entirely fermented in the colon by the microbiota. For the purpose of enhancing RS (dietary fiber) in cooked rice, we evaluated how growing environment and cooking method affect the RS in high amylose rice varieties. Forty high apparent amylose rice varieties were grown in three environments (2 years in AR and 1 year in TX). Individually, the response of rice varieties to growing environment in RS content differed. However, on average, RS contents were higher for the two years grown in AR than in TX. In comparison a high amylose mutant, which contained higher RS than found in nature variants, had higher RS content in TX than in AR. Around the globe, rice is typically cooked either at a fixed rice-to-water ratio or in excess water. We compared the effect of these two cooking methods on RS content using rice varieties varying in amylose content, gelatinization temperature, and minimum cooking time. Even though the rice cooked with excess water had higher percentage of fully cooked kernel and higher cooked rice moisture than the rice cooked at a fixed rice-to-water ratio, the RS were not significantly different between the two methods.