What is the Rice Starch for? Benefits and properties

Rice starch is mainly composed of two polymers: amylose and amylopectin. Its approximate composition is 80% amylopectin and 25% amylose, although this amount may vary depending on the variety and the process. It also has other minor constituents associated with it, such as proteins, lipids and phosphoric components. The rice starch granules are quite small in size (2 microns).

Rice starch is quite digestible and also hypoallergenic, it has a white color and a mild flavor, it has good resistance to acids and is more stable to the freezing and thawing process than the starch of other cereals.

Starch is preserved in the endosperm of rice grains, in the endosperm, there are also four types of proteins (glutelin, prolamine, globulin and albumin), these proteins adhere to the surface of the starch and are difficult to eliminate, depending on the isolated method, the protein residue of the starch can be higher or lower.

The solubility and volume-increasing capacity is greater with increasing temperature, starches can have differences in volume increase and agglutination, depending on their organization and the amount of amylose and amylopectin they have.

Digestibility of rice starch

There is a wide range of starches with different ratios of amylose and amylopectin. Based on which, the starch will present different properties, especially in the speed of digestion and glycemic response.

Rice starch is generally low in amylose, is rapidly absorbed, and has a relatively high glycemic index, however, when the number of amylose increases, the rate of digestion decreases.

As the amylopectin is digested faster than amylose, cereals with a high amylose content have a lower glycemic index. The milling of rice grains decreases the amount of amylose, thus increasing its digestibility, which is why the more processed rice or white rice are better digested than whole rice. The more processed the rice is, the less amylose and therefore more easily digestible and higher glycemic response.

There are some specific varieties of rice starch with high amylose content, (more than 24%), with a low glycemic response, selected for use as an ingredient in processed products. But except for those cases, the glycemic response of rice starch is quite high.

What is it for?

Power source

In general, rice starch is very digestible and can be absorbed quickly. Intake of high glycemic carbohydrates is useful during prolonged exercise to maintain blood glucose levels and delay the onset of fatigue. At the end of training they are also suitable for restoring muscle glycogen levels.

In addition, rice is a cereal that offers different varieties, among which some with slower digestibility can be found, which is why they give rise to a lower glycemic response after ingestion, making them very suitable for diabetics, hypertriglyceridemic and in sports preparation.

Technological function

Finally, starch or rice starch, is used as a thickening agent in many food products.

Dose

Carbohydrates in the diet should account for 45-55% of the daily caloric value in the normal population, however, in people who carry out moderate to intense sports activities, they require a slightly higher contribution to cover the needs, around 55- 65% of the total caloric value.