Effects of processing methods of rice gel on starch digestibility and textural properties

Abstract

AbstractBackground and objectivesThe objective of this study was to investigate the effects of rice variety, rice material such as flour or cooked grain, and preparation conditions on starch digestibility and textural properties of gels.FindingsRice gels were prepared from cooked‐rice grain via high‐speed shear homogenization or rice flour using five high‐amylose rice varieties. Rice‐flour gels formed a harder and more brittle gel structure than did cooked‐rice gels of the same rice variety. Starch digestion of gels was evaluated using both gels of fixed size and ground gels. The extent of starch digestion for cooked‐rice gels of fixed size negatively correlated with the peak area ratio of DP13‐24 of amylopectin. Starch digestibility was higher in rice‐flour gels compared to cooked‐rice gels of the same rice variety. When using gels of fixed size, a significant correlation was observed between the extent of starch digestion and textural properties.ConclusionsBoth rice variety and processing conditions strongly influenced the textural properties of gels, resulting in the formation of a stronger gel structure and suppression of the extent of starch digestion in rice gels.Significance and noveltyThe combination of both rice variety and processing condition significantly suppresses starch digestibility of rice gels.