High resistant starch rice: variation in starch related SNPs, and functional, and sensory properties

Authors: Chen, Ming Hsuan; Bett Garber, Karen; Lea, Jeanne; McClung, Anna; BERGMAN, CHRISTINE - University Of Nevada Las Vegas, Las Vegas, Nv

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2021
Publication Date: 12/30/2021
Citation: Chen, M., Bett Garber, K.L., Lea, J.M., McClung, A.M., Bergman, C.J. 2021. High resistant starch rice: variation in starch related SNPs, and functional, and sensory properties. Foods. https://doi.org/10.3390/foods11010094.
DOI: https://doi.org/10.3390/foods11010094

Interpretive Summary: Dietary fiber has health benefit in preventing chronic diseases. Resistant starch (RS) is the primary form of dietary fiber in cooked milled rice, thus it is the logical choice in enhancing dietary fiber content in rice. Previous study suggested that some global varieties were a good genetic resource for improving US varieties for this goal. For this study, we took a step further evaluating the processing property and sensory quality of the cooked rice of eight global varieties that were identified having the highest RS in a previous study. For comparison, two representative high amylose US varieties were included. Trained panelists using descriptive sensory analysis determined that only two of 14 cooked rice texture attributes were different between the high RS group of varieties and other high amylose US varieties that have similar functional properties. Moreover, in an evaluation of the functional properties, few differences were found between the two subgroups of varieties. These results demonstrate the potential for increasing RS in US rice varieties that will enhance the health benefits of cooked rice while having minimum impact on cooked rice texture or processing quality.

Technical Abstract: Human diets containing greater resistant starch (RS) are associated with superior glycemic control. Although high amylose rice has higher RS (29 g/kg to 44 g/kg) than lower amylose content varieties, sensory and processing properties associated with RS have not been evaluated. This study used variants of Waxy and starch synthase II a (SSIIa) genes to divide high amylose (256 g/kg to 284 g/kg) varieties into three haplotypes to examine their effects on RS, RVA parameters, and 14 cooked rice texture properties. RVA characteristics were influenced by both genes with peak and hotpaste viscosity differentiating the three haplotypes. Setback from hotpaste viscosity was the only RVA parameter correlated with RS content across three haplotypes (r = -0.76 to -0.93). Cooked rice texture attributes were impacted more by Waxy than by SSIIa with initial starch coating, roughness, and intact particles differentiating the three haplotypes. Pairwise correlation (r = 0.46) and PCA analyses suggested that roughness was the only texture attribute associated with RS content; while protein content influenced roughness (r = 0.49) and stickiness between grains (r = 0.45). In conclusion, variation exists among genetic haplotypes with high RS for sensory traits that will appeal to diverse consumers across the globe with limited concern for negatively affecting grain processing quality.