The Study
Microwave reheating enriches resistant starch in cold-chain cooked rice: A view of structural alterations during digestion.
This study looked at how rice changes inside a lab test tube when you cool it and then microwave it. It found that the rice’s starch gets a different shape, which makes it harder for fake digestive enzymes to break it down. But it didn’t test this on people or animals — so we don’t know if eating it does anything to your body.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When you cook rice, cool it down, and then reheat it in the microwave, its internal structure changes in a way that makes your body digest it more slowly.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 55 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes happen in a test tube, not in your body — so we don't know yet if eating this rice actually lowers blood sugar in people.
- 2Cooling rice makes 38% of its starch slowly digestible; reheating it in the microwave makes 30% of it resistant to digestion — meaning it doesn't turn into sugar as easily.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
International journal of biological macromolecules
Year
2022
Authors
Zihang Cheng, Jiang Li, D. Qiao, Lili Wang, Si-ming Zhao, Binjia Zhang
Related Content
Claims (8)
Cooling and reheating cooked rice increases its resistant starch content more than two and a half times and lowers the rise in blood glucose and insulin after eating.
Reheating cold-stored cooked rice in a microwave changes some of its starch structure in a way that increases the amount of resistant starch to about 30.06%, making it harder for digestive enzymes to break down.
Chilling cooked rice changes its internal structure to create more tiny pores, which is associated with slower breakdown of starch during digestion and higher levels of slowly digestible starch.
When cooked rice is cooled and then reheated in a microwave, laboratory tests show it contains about 30.06% resistant starch, which is more than freshly cooked rice tested the same way.
Chilling cooked rice at 4°C changes its starch structure to increase slowly digestible starch to 38.16% by reducing enzyme access to amorphous regions through increased crystallinity and reduced pore size.
Reheating cold-stored cooked rice in a microwave does not change the V-type starch crystals or short-range molecular structure, but it increases the rice's resistance to digestive enzymes, meaning other structural features like pore arrangement and B-type crystal breakdown are responsible for the increased resistant starch.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.