Arsenic and toxins in rice; Do this simple thing before cooking / Soaking rice reduces contamination / Know the anti-nutritional compounds of rice

Rice is one of the most consumed foods on the Iranian table; A product that, in addition to its nutritional value, may contain anti-nutritional compounds and chemical pollutants such as heavy metals and pesticide residues. However, it is possible to reduce the amount of some of these pollutants and compounds with a simple and practical method, that is, soaking and washing the rice properly before cooking.

Fakhera Behbahani: Rice and bread are the main food items in the consumption basket of Iranian households, and many families consume rice several times during the week for lunch or dinner. For this reason, it is very important to pay attention to how to prepare this food. Proper soaking and washing of rice before cooking is one of the measures that can help reduce some of its possible contamination. However, lack of time or lack of awareness of the benefits of this work makes some people ignore this step.

How does soaking rice help reduce arsenic?

The use of water contaminated with heavy metals and industrial effluents in some agricultural areas has raised concerns about the contamination of crops, including rice, with substances such as arsenic, cadmium, and mercury.

Some studies show that soaking rice before cooking can help reduce its arsenic content. According to the reported results, soaking rice for one night or at least three to four hours, with a ratio of one pint of rice to six pints of water, and then discarding the soaking water and rinsing again, can reduce the amount of arsenic in rice by about 80% under certain conditions.

If you don't have enough time to soak the rice, washing it several times and discarding the washing water can also help to reduce some of the surface pollutants. Also, changing the water during the soaking period and using fresh water may increase the removal rate of some water-soluble compounds.

Of course, the amount of pollution reduction depends on the type of rice, the amount and chemical form of pollutants and the preparation method; Therefore, soaking and washing should not be considered as a method to completely remove heavy metals from rice.

The effect of soaking rice on the reduction of pesticide residues

The use of pesticides in agriculture and the persistence of some of these compounds in the environment increases the possibility of transferring their residues from soil and water to agricultural products, including rice. However, the amount of pesticides remaining in the product depends on the type of poison, its chemical characteristics and its stability in the environment and during the food preparation process. For this reason, no single method can be considered effective for removing all pesticides.

According to the results of a study conducted in Iran, proper washing has been able to reduce between 12 and 88% of the residues of some pesticides used in rice cultivation. Most of this reduction is related to compounds that have a weaker bond with the rice grain surface.

Also, in some studies, soaking rice the night before cooking has been associated with a significant reduction in the residues of a number of pesticides; However, the reducing effects of this method have been reported in a shorter period of time, about three to four hours. However, the effectiveness of soaking varies for each pesticide and cannot be expected to completely remove pesticide residues.

What are the anti-nutritional compounds of rice?

Grains and legumes may contain anti-nutritional compounds such as phytic acid and some enzyme inhibitors. These compounds can affect the absorption of nutrients or the digestion process.

Brown rice usually has more phytic acid than white rice due to the preservation of the bran. Phytic acid can bind with some minerals, especially iron and zinc, thereby reducing their absorption in the digestive tract.

On the other hand, some grains and legumes contain enzyme inhibitors; Compounds that can inhibit the activity of digestive enzymes, including trypsin. The amount of these substances in rice and their effect depends on the type of grain and processing conditions.

Some studies have shown that soaking can help reduce some of the anti-nutritional compounds in rice. However, the amount of reduction depends on the type of composition, duration of soaking and processing conditions, and not all of these substances can be considered completely soluble in water or removable by soaking.

Soaking rice also helps to separate part of the surface starch of the grains; An issue that can affect the cooking characteristics, including the stickiness of the rice. However, a reduction in surface starch does not necessarily mean a significant reduction in total rice calories or carbohydrates.

All in all, soaking and washing rice properly before cooking is a simple way to help reduce some of the residues of some pesticides, water-soluble compounds, and some grain surface materials. However, the effectiveness of this method depends on the type of pollutant and the characteristics of rice and does not replace the production of a healthy product, control of water and soil pollution, and compliance with food safety standards.