One type of resistant starch is formed when foods are cooled after cooking. This process is called starch retrogradation.
It occurs when some starches lose their original structure due to heating or cooking. If these starches are later cooled, a new structure is formed.
The new structure is resistant to digestion and leads to health benefits.
What’s more, research has shown that resistant starch remains higher after reheating foods that have previously been cooled.
Through these steps, resistant starch may be increased in common foods, such as potatoes, rice and pasta.
Potatoes are a common source of dietary starch in many parts of the world.
However, many debate whether potatoes are healthy or not. This may be partially due to potatoes’ high glycemic index, a measure of how much a food raises blood sugar levels.
While higher potato consumption has been associated with an increased risk of diabetes, this could be caused by processed forms like french fries rather than baked or boiled potatoes.
How potatoes are prepared impacts their effects on health. For example, cooling potatoes after cooking can substantially increase their amount of resistant starch.
One study found that cooling potatoes overnight after cooking tripled their resistant starch content.
Additionally, research in 10 healthy adult men showed that the higher amounts of resistant starch in potatoes led to a smaller blood sugar response than carbs with no resistant starch.
It is estimated that rice is a staple food for approximately 3.5 billion people worldwide, or over half of the world’s population.
Cooling rice after cooking may promote health by increasing the amount of resistant starch it contains.
One study compared freshly cooked white rice to white rice that was cooked, refrigerated for 24 hours and then reheated. The rice that was cooked then cooled had 2.5 times as much resistant starch as the freshly cooked rice.
Researchers also tested what happened when both types of rice were eaten by 15 healthy adults. They found that eating the cooked then cooled rice led to a smaller blood glucose response.
While more research in humans is needed, one study in rats found that eating rice that had been repeatedly heated and cooled led to less weight gain and lower cholesterol.
Pasta is commonly produced using wheat. It is consumed all over the world.
There has been very little research on the effects of cooking and cooling pasta to increase resistant starch. Nevertheless, some research has shown that cooking then cooling wheat can indeed increase resistant starch content.
One study found that resistant starch increased from 41% to 88% when wheat was heated and cooled.
However, the type of wheat in this study is more commonly used in bread than pasta, although the two types of wheat are related.
Based on research in other foods and isolated wheat, it is possible that resistant starch is increased by cooking then cooling pasta.
Regardless, more studies are needed to confirm this.
In addition to potatoes, rice and pasta, resistant starch in other foods or ingredients can be increased by cooking and then cooling them.
Some of these foods include barley, peas, lentils and beans).
More research is needed to determine the full list of foods in this category.
SUMMARY:The resistant starch in rice and potatoes may be increased by cooling them after cooking. Increasing resistant starch may lead to smaller blood sugar responses after eating.