Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPING NOVEL PROCESSES FOR INCORPORATING THE UNIQUE NUTRITIONAL AMD FUNCTIONAL PROPERTIES OF RICE INTO VALUE-ADDED PRODUCTS Title: Nutritionally-important starch fractions of rice cultivars grown in southern United States.

Authors
item Patindol, James
item Guraya, Harmeet
item Champagne, Elaine
item McClung, Anna
item McClung, Anna

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 9, 2010
Publication Date: June 1, 2010
Citation: Patindol, J.A., Guraya, H.S., Champagne, E.T., Mcclung, A.M. 2010. Nutritionally-important starch fractions of rice cultivars grown in southern United States. Journal of Food Science. 75:H137-H144.

Interpretive Summary: For health and nutritional value, starches in foods can be classified as readily digestible (RDS), slowly digestible (SDS), and resistant starch (RS). RDS is the fraction that is converted to glucose within 20 minutes; SDS is hydrolyzed to glucose between 20 to 120 minutes; whereas, RS remains undigested after 120 minutes. Literature indicates that SDS and/or RS have significant implications on human health, particularly glucose metabolism, diabetes management, colon cancer prevention, mental performance, and satiety. In this work, the RDS, SDS, and RS of 16 cultivars grown in five southern U.S. rice growing locations (Arkansas, Louisiana, Mississippi, Missouri, and Texas) were determined by an enzymatic procedure. RDS, SDS, and RS were 52.4-69.4, 10.3-26.6, and 1.2-9.0%, respectively, of cooked rice dry weight. Sample preparation method, cultivar, and growing location contributed to the variations in RDS, SDS, and RS contents. Interestingly, some cultivars were identified that had high levels of RS (e.g. Bowman and Rondo) or SDS (e.g. Dixiebelle and Tesanai), and were also stable across growing locations. The observed differences in RDS, SDS, and RS among the samples are indicative of wide genetic diversity in rice. Such diversity may be exploited to enhance rice nutritionally-important starch fractions through the use of conventional and/or emerging technologies for plant breeding and varietal improvement. The findings are also valuable in meeting consumers’ growing interest on healthy eating, and food processors’ endeavors to develop health-promoting, rice-based food products.

Technical Abstract: Dietary starches can be classified into three major fractions, according to in vitro digestibility: rapidly digestible (RDS), slowly digestible (SDS), and resistant starch (RS). Literature indicates that SDS and/or RS have significant implications on human health, particularly, glucose metabolism, diabetes management, colon cancer prevention, mental performance, and satiety. In this work, cooked rice nutritionally-important starch fractions (RDS, SDS, and RS) were assayed in vitro, making use of 16 cultivars grown in five southern U.S. rice growing locations (Arkansas, Louisiana, Mississippi, Missouri, and Texas). RDS, SDS, and RS were 52.4-69.4, 10.3-26.6, and 1.2-9.0%, respectively, of cooked rice dry weight. Cultivar, location, and cultivar×location interaction contributed to the variations in RDS, SDS, and RS contents. Means pooled across locations indicated that SDS was higher for the Louisiana samples than those from Texas, whereas, RS was higher for the Texas samples than those from Arkansas, Louisiana, and Mississippi. Some cultivars were identified that possessed high levels of RS (e.g. Bowman and Rondo) or SDS (e.g. Dixiebelle and Tesanai-2), and were also stable across growing locations. Apparent amylose content correlated positively with RS (n=80, r=0.54, p=0.001), negatively with RDS (n=80, r=-0.29, p=0.05), and insignificantly with SDS (n=80, r=0.21, p=0.05). RS and SDS were not collinear (n=80, r=-0.18, p=0.05); it does not follow that a cultivar high in RS will also be high in SDS, and vice versa. The observed differences in RDS, SDS, and RS among the samples are indicative of wide genetic diversity in rice.

Last Modified: 10/31/2014
Footer Content Back to Top of Page