Refined grains, in contrast to whole grains, refers to grain products consisting of grains or grain flours that have been significantly modified from their natural composition. The modification process generally involves the mechanical removal of bran and germ, either through grinding or selective sifting. Further refining includes mixing, bleaching, and brominating; additionally, thiamin, riboflavin, niacin, and iron are often added back in to nutritionally enrich the product. Because the added nutrients represent a fraction of the nutrients removed, refined grains are considered nutritionally inferior to whole grains. However, for some grains the removal of fiber coupled with fine grinding results in a slightly higher availability of grain energy for use by the body. Furthermore, in the special case of maize, the process of nixtamalization (a chemical form of refinement) yields a considerable improvement in the bioavailability of niacin, thereby preventing pellagra in diets consisting largely of maize products.
| Wheat | Rice | |||||
|---|---|---|---|---|---|---|
| Whole | Refined | Enriched | Whole | Refined | Enriched | |
| Food energy | 100% | 107% | 107% | 100% | 99% | 99% |
| Carbohydrates | 100% | 105% | 105% | 100% | 104% | 104% |
| Fiber | 100% | 22% | 22% | 100% | 37% | 37% |
| Protein | 100% | 75% | 75% | 100% | 90% | 90% |
| Thiamin (B1) | 100% | 27% | 176% | 100% | 17% | 144% |
| Riboflavin (B2) | 100% | 19% | 230% | 100% | 53% | 53% |
| Niacin (B3) | 100% | 20% | 93% | 100% | 31% | 82% |
| Pantothenic Acid (B5) | 100% | 43% | 43% | 100% | 68% | 68% |
| Pyridoxine (B6) | 100% | 13% | 13% | 100% | 32% | 32% |
| Folate (B9) | 100% | 59% | 350% | 100% | 40% | 1155% |
| Vitamin E | 100% | 5% | 5% | 100% | 18% | 18% |
| Calcium | 100% | 44% | 44% | 100% | 100% | 100% |
| Iron | 100% | 30% | 120% | 100% | 54% | 293% |
| Magnesium | 100% | 16% | 16% | 100% | 17% | 17% |
| Phosphorus | 100% | 31% | 31% | 100% | 35% | 35% |
| Potassium | 100% | 26% | 26% | 100% | 52% | 52% |
| Sodium | 100% | 40% | 40% | 100% | 71% | 71% |
| Zinc | 100% | 24% | 24% | 100% | 29% | 29% |
| Copper | 100% | 38% | 38% | 100% | 79% | 79% |
| Manganese | 100% | 18% | 18% | 100% | 29% | 29% |
| Selenium | 100% | 48% | 48% | 100% | 65% | 65% |
Read more about Refined Grains: See Also
Famous quotes containing the words refined and/or grains:
“... in the fierce competition of modern society the only class left in the country possessing leisure is that of women supported in easy circumstances by husband or father, and it is to this class we must look for the maintenance of cultivated and refined tastes, for that value and pursuit of knowledge and of art for their own sakes which can alone save society from degenerating into a huge machine for making money, and gratifying the love of sensual luxury.”
—Mrs. H. O. Ward (1824–1899)
“Listen. The minstrels sing
In the departed villages. The nightingale,
Dust in the buried wood, flies on the grains of her wings
And spells on the winds of the dead his winter’s tale.”
—Dylan Thomas (1914–1953)