- Research Article
- 10.1002/jsfa.70538
Influence of production area and storage on starch digestibility and glycemic properties of rice flour.
- Mar 07, 2026
- Journal of the science of food and agriculture
- Chiemerie Famous Nwaeche + 3 more +3
The starch digestibility and glycemic responses of rice flour are influenced by intrinsic factors, such as its composition, and extrinsic factors, including storage. This study aimed to examine the impact of extrinsic factors on rice flour production by investigating the starch digestibility of rice flour from the same rice seeds ('Udai21') in four production areas: Fukushima, Tochigi, Toyama, and Yamagata prefectures. After 6 months of storage under ambient conditions at 30 °C, moisture content increased across all samples, whereas the crude protein content remained stable, with minor increases. Apparent lipid content increased slightly in the Toyama sample. Total starch content increased in all samples. Freshness indicators, pH and ΔE, showed regional variations, with Fukushima exhibiting the least degradation and Toyama the most. Rapidly digestible starch declined significantly in all samples, whereas changes in slowly digestible starch were insignificant, although regional variations were apparent. The estimated glycemic index (eGI) decreased in all samples, with Toyama showing the most significant drop from 136.0 to 125.0. The regional origin of rice flour influenced its physicochemical properties and starch digestibility significantly. Reductions in eGI and the equilibrium concentration of starch hydrolysis after storage suggest that 'Udai21' aged rice flour may produce a slower postprandial glycemic response, likely due to the formation of amylose-lipid or amylose-protein complexes that increase resistance to enzymatic breakdown. These results highlight the inherent variability in rice flour arising from natural compositional differences driven by environmental factors. © 2026 Society of Chemical Industry.
Read more