In the kitchen, there are some practices that we do automatically and we don't even think to question the sense of doing them, just because someone once taught us that this is the way it should be done. Washing rice is one of them. What is the point? Why do we do it?
Logically, one might suppose that the purpose of rinsing it with a copious stream of water over a strainer is to eliminate impurities that may have been carried from the field, during transportation, in the warehouse, or when packing it. However, there are people who not only rinse it but also let it soak for a while.
Researcher Leticia García Rico explained that, according to a study conducted by academics from the College of Food Science and Technology of the Henan University of Technology, in Zhengzhou, China, washing and soaking rice protects us from consuming toxic metals.
The researchers conducted an experiment in which they washed, soaked, and cooked two types of rice (japonica cultivar Xinfeng 2 and indica cultivar T-You 15) using three different cooking methods (frying pan, pressure cooker, and microwave).
The analyses showed that washing significantly reduced the concentrations of cadmium, arsenic, and lead, in addition to the fact that the three types of cooking reduced the bioaccessibility of these elements.
These findings demonstrate that washing and soaking rice can protect the diner from exceeding the concentrations of these metals that naturally exist in this and other foods and that in excess can trigger carcinogenic and non-carcinogenic health risks for adults and children.
Further research is needed to identify optimal washing or soaking conditions, as well as cooking practices capable of reducing the concentration of metals without affecting the nutrients in the rice. As far as possible, use purified (treated) water for washing and cooking food, especially in localities with problems of metal contamination in water.
Washing and disinfecting fruits and vegetables should always be a routine practice before consumption, as well as legumes such as beans, lentils, or chickpeas, since they may contain impurities that can cause gastrointestinal foodborne illnesses.