Early-season rice as a potentially healthier diet: Insights from starch digestion properties

Early-season rice, typically characterized by a high amylose content, often exhibits poor palatability. However, its high amylose content and potentially distinctive physicochemical properties may contribute to slower starch digestion, which could result in a reduced glycemic response and associated health benefits. To test this hypothesis, this study compared starch digestion and physiochemical properties between three high-amylose early-season rice varieties and three high-palatability late-season rice varieties. Results showed that, on average, the early-season varieties exhibited a 52% longer active digestion duration and a 39% lower glucose production rate than the late-season varieties. In addition to having higher amylose content, the early-season varieties had lower amylopectin content and higher amylose-to-amylopectin ratios compared to the late-season varieties. They also differed in pasting properties, with the early-season varieties demonstrating lower peak and breakdown viscosities, but higher trough, final, and setback viscosities. Across all six varieties, these physicochemical traits showed significant correlations with active digestion duration and glucose production rate. These findings support the hypothesis of this study and highlight the potential of early-season rice as a healthier dietary option, particularly for individuals managing diabetes. This study also provides a new rationale for promoting the development of early-season rice.