Is rice resistant starch after refrigeration?

October 30, 2025 •

2 min read

According to a 2015 study, cooked white rice that was refrigerated for 24 hours and then reheated had more than double the amount of resistant starch compared to freshly cooked rice. The answer to "is rice resistant starch after refrigeration?" is a resounding yes, due to a process called retrogradation.

Quick Summary

Cooling cooked rice in the refrigerator increases its resistant starch content through a process called retrogradation. This type of starch resists digestion, acting like fiber to improve gut health, moderate blood sugar spikes, and potentially aid in weight management. These benefits are retained even after reheating, as long as proper food safety protocols are followed.

Key Points

Refrigeration boosts resistant starch: Cooling cooked rice triggers starch retrogradation, significantly increasing its resistant starch content.
Improved blood sugar control: The increased resistant starch in cooled rice results in a lower glycemic response, preventing sharp blood sugar spikes.
Enhanced gut health: Acting as a prebiotic, resistant starch feeds beneficial gut bacteria and helps produce nourishing short-chain fatty acids.
Retains benefits after reheating: Reheating refrigerated rice does not destroy the resistant starch, preserving the health benefits.
Safe cooling is essential: To prevent food poisoning from Bacillus cereus, rice must be cooled quickly and refrigerated within one hour of cooking.
Aids in weight management: The higher fiber content and reduced usable calories in cooled rice can help increase feelings of fullness.
Choosing the right rice matters: Varieties with higher amylose content, like parboiled rice, are more effective at forming resistant starch.

The Science Behind Refrigerated Rice: Starch Retrogradation

Rice contains starch, made of amylose and amylopectin. Cooking causes starch granules to swell (gelatinization), making them digestible. When cooled, particularly in refrigeration, starch molecules, especially amylose, reassociate into a more crystalline structure in a process called retrogradation. This retrograded starch resists digestion, and is known as resistant starch.

Key Health Benefits of Increased Resistant Starch

Eating cooled and reheated rice can offer several health benefits:

Improved Blood Sugar Control: Resistant starch slows digestion, leading to a more gradual rise in blood sugar. This is helpful for managing blood sugar levels.
Enhanced Gut Health: Resistant starch acts as a prebiotic, feeding beneficial gut bacteria. These bacteria produce short-chain fatty acids (SCFAs), such as butyrate, which support colon health.
Potential Weight Management: By promoting fullness and reducing calorie absorption, resistant starch may assist with weight management.
Lowered Inflammation: SCFAs produced from resistant starch fermentation can help reduce inflammation.

Fresh vs. Refrigerated/Reheated Rice


Feature	Freshly Cooked Rice	Refrigerated/Reheated Rice
Digestion Speed	Rapidly digested into glucose.	Digested more slowly.
Glycemic Index (GI)	Typically higher GI.	Lower GI.
Resistant Starch	Minimal.	Significantly higher.
Available Calories	Standard.	Reduced.
Gut Health Impact	Minimal prebiotic effect.	Acts as a prebiotic.

Maximizing Resistant Starch in Your Rice

To increase resistant starch in your rice:

Choose Rice Wisely: Varieties high in amylose, like basmati or parboiled, form more resistant starch upon cooling.
Consider Adding Fat: Adding a teaspoon of coconut oil while cooking might boost resistant starch formation.
Cool Quickly: Spread cooked rice thinly to cool fast, aiding retrogradation and food safety.
Refrigerate: Cool for at least 12-24 hours for maximum effect.
Reheat Safely: Reheating doesn't destroy resistant starch, but heat to 165°F to kill bacteria.

Food Safety: A Critical Consideration

Proper handling of cooked rice is crucial due to the risk of Bacillus cereus bacteria. To avoid food poisoning, cool rice rapidly within one hour of cooking and refrigerate in an airtight container. Consume within 24 hours and never leave cooked rice at room temperature for more than two hours.

The Final Verdict on Refrigerated Rice

Cooling cooked rice is a simple way to increase its resistant starch content through retrogradation. This makes rice a better source of fiber, benefiting metabolic health and the gut microbiome. By following safe cooking and storage practices, you can enjoy the health advantages of cooled rice. For blood sugar management or gut health improvement, cooled rice is a viable option.

For more details on the health benefits of resistant starch, you can read further from resources like Healthline.

Frequently Asked Questions

Resistant starch is a type of carbohydrate that is not digested in the small intestine but instead ferments in the large intestine. It functions similarly to dietary fiber and serves as food for beneficial gut bacteria.

When cooked rice cools, the starch molecules (amylose and amylopectin) re-arrange into a more compact, crystalline structure. This process is called retrogradation, and it makes the starch resistant to digestion by enzymes.

Yes, you can. Reheating refrigerated rice does not significantly diminish the resistant starch content. In fact, studies show that cooked, cooled, and then reheated rice can have even higher levels of resistant starch than freshly cooked rice.

Yes, as long as it has been handled properly. The rice must be cooled down quickly (within an hour) after cooking and stored in the refrigerator. Consume it within 24 hours to minimize the risk of bacterial growth.

Not all of the starch becomes resistant starch. A portion of it is converted during the retrogradation process, with the amount varying based on factors like the type of rice and how it was cooked and cooled.

Some anecdotal evidence and studies suggest that adding a teaspoon of coconut oil to rice while cooking can potentially increase the formation of resistant starch when the rice is cooled. This may be due to the oil complexing with the amylose.

The resistant starch in cooled rice acts as a prebiotic, which feeds the beneficial bacteria in your gut. This fermentation produces short-chain fatty acids like butyrate, which can reduce inflammation, support colon cell health, and promote a balanced microbiome.