The Science of Cooking Rice Using Grayns Rice Cooker


Rice just like any other carbohydrate is made up of two starches. Rice contains starches which exist in a combination of Amylose and Amylopectin. Amylopectin are heavily branched molecules that are water soluble and gelatinize easily when rice is cooked. Amylose on the other hand, are a linear strongly bonded molecule that are not easily soluble in water.

The Food and Agriculture Organization of the United Nations states the following. “Altering the amylose/amylopectin ratio changes physiologic responses which could influence satiety. High-amylose starches are associated with a lower glycemic response than low-amylose starches, and they may also empty more slowly from the stomach.

Therefore, it is the ratio of these starches that determine if a particular carbohydrate classifies as RDS (Rapidly Digestible Starch) or SDS (Slowly Digestible Starch). Rice having very high amylopectin molecules and lesser amylose molecules classifies it as an RDS. On the other hand, Oats having relatively larger quantities of Amylose molecules and lesser Amylopectin molecules classifies it as a SDS.

Carbohydrates with a lot of RDS, as is the case with rice, tend to have a high glycemic index. They cause blood glucose to rise quickly and stay high longer and this in turn spikes blood sugar levels and the health issues that come along with high blood sugar. RDS is a caloric equivalent of sugar.

In comparison, SDS or “Slowly Digestible Starches” do not break down so quickly after consumption as the name itself suggests. Thus SDS is healthier because it does not raise blood glucose levels quickly nor do they stay high longer.

When rice is heated in water a natural chemical process begins to take place. At a certain temperature which is the gelatinization temperature of rice, the RDS molecules start to move out of the rice grain and dissolve into the water. If this temperature is held long enough, it would allow most of the RDS molecules to leave the rice grain and move into the water. Therefore, getting rid of the RDS rich water would deliver rice that is high in Amylose and less in Amylopectin.

The Grayns RevoCook technology cooks rice scientifically the way nature meant it to be cooked. Therefore rice cooked in the Grayns Rice Cooker is never allowed to boil. This is because, if the rice is allowed to boil then the cell wall of the rice grain breaks and allows some of the RDS molecules to return back into the rice grain. Therefore, the gelatinization temperature is intuitively held long enough to ensure most of the RDS molecules depart from the rice grain and dissolve into the water.

The end result is that rice cooked in the Grayns Rice Cooker has a higher Amylose to Amylopectin ratio as opposed to a higher Amylopectin to Amylose ratio thereby transforming it into an SDS. With the RDS removed rice is no longer the sugar that it would be. Rather it becomes a healthier carbohydrate almost on par with Oats that provides the energy while digesting slowly into our blood stream without spiking blood glucose levels and keeping us full for longer.