White, brown and parboiled rice: how processing changes the grain

Useful to know

On the packaging of rice, we often see several definitions at the same time: long-grained, brown, white or parboiled. They are not interchangeable. One name describes the shape, another - the removed layers of grain, and a third - preliminary technological processing. This explains why two products that look similar in dry condition can give a different texture after boiling. To choose a suitable product, we need to read these characteristics together, not look for a universal sign of quality. [1, 2]

After removing the outer husk, brown rice is obtained, in which the bran remains on the grain. In the additional milling and polishing, outer layers are removed and white rice is obtained. Therefore, brown is not necessarily the name of a separate variety. The difference may come from processing the same starting grain. The International Rice Research Institute explains that by removing the bran, some of the substances contained therein are lost. [1]

Preserved layers also matter for storage. Fats in bran can oxidize and lead to rancidity. This is one of the reasons why white and brown rice are not seen as completely the same products of a different color. However, the very definition of "whole grain" does not say everything about the freshness of the particular packaging. It is necessary to take into account the condition of the product and the manufacturer's instructions, instead of drawing conclusions from the color for each of its features. [1]

Parboiling is a different process. In the processes described by FAO, the paddy rice undergoes soaking and heat treatment, then is dried before subsequent stages. Starch undergoes changes that affect the structure. Some of the substances from the outer layers can pass inwards. Parboiled rice is not just an already cooked dish and should not be taken as a ready-to-eat product just because of the name. It usually requires subsequent preparation according to the specific packaging. [3]

The bonding of the cooked grains also depends on the starch. Two of its main components are amylose and amylopectin. The FAO considers amylose content as an important indicator of cooking behavior, along with gelatinization temperature and gel consistency. Therefore, the length of the grain can be a guide, but it does not replace the information about the variety and processing. Rice for a dish with separated grains and rice for a sticky texture solve various culinary tasks. [2]

And post-harvest conditions matter. FAO describes storage changes that can affect grain expansion and texture after boiling. Therefore, the result is not determined by just one word on the label. A practical way to compare at home is to record the product used, the amount of water and the result obtained, without changing all the conditions at once. Thus, the next preparation is based on observation of the particular rice, instead of the assumption that each species should behave the same. [3]