The grains that we grow, harvest and eat as cereals are produced by the plants as their next generation. Observing the cereal grains from this perspective helps us better understand and appreciate the structure and nutritional composition in the grains.
As mentioned in the earlier posting discussing the structure of a husked millet grain, the bran layer is found to be rich in fibers, minerals and essential fatty acids. The concentration of so many nutrients in the bran layer is not really an accident.
The fatty acids help protect the moisture content of the grains during its harsh dry days in the rain fed farm. This is similar to us humans using moisturizing creams and vegetable oils on our skins during winter months to protect if from drying and cracking. The proportion of the different fatty acids – saturated, unsaturated, etc. varies from variety to variety. Minerals in biological systems play the critical role of catalysts in various metabolic activities. The seed or the seedling, do not need for this to be within the plant, but rather they need these minerals to be accessible as they start growing roots and shoots. The fibers form the framework within which the carbohydrate rich endosperm develops into a full fledged rice kernel. The flakiness of the bran layer can be observed as the grains mature and dry.
Thus, the nutrients in the bran layer serve the primary purpose with which the plant produces the grains – to nourish and protect it as it grows into the next generation. Retaining as much of the bran as possible during processing helps us realize a better deal when we steal the grains and use it for our own nourishment. And if we are not careful enough, other species in the ecosystem shall relish in this treasure trove of nutrition that we would have unlocked by removing the husk.