Rethinking par-boiling to improve the quality of rice grain

Rice is the dietary carbohydrate staple of half the world, diet it is nutritionally poor, high in the contaminants cadmium and arsenic, is high in soluble starch and is prone to causing food poisoning through Bacillus subtillus. Rice is often parboiled, where hushed rice is heated in steam or in water at 500C for 20 mins, then dried, dehusked and then milled to produce polished rice. Par boiling has multiple advantages in that it kills pests, improves textural properties of rice (through rearrangement of starch crystals) and leads to less breakage of grains during milling. However, as traditionally conducted, parboiling does not lead to loss of soluble starch (which is responsible for rice’s high glycemic index {[GI], linked to high rates of diabetes is high rice consumers, and locks in toxins high in rice such as arsenic. We have discovered that rice parboiling can be conducted by soaking whole grain rice overnight in ambient water (saving heating energy) and leading to greatly reduced arsenic content. It is now key to see what this novel rice parboiling process does to other key aspects of rice properties, such as nutrients, bacterial loadings and GI.