Refined grains, in contrast to whole grains, are grains and their flours whose brans and/or endosperms have been mechanically removed. Further refining includes fine grinding, sifting, mixing, bleaching, and brominating. Finally, thiamin, riboflavin, niacin, and iron are generally added back in to enrich the flour. Because the added nutrients represent a fraction of the nutrients removed, refined grains are considered nutritionally inferior to whole grains. However, the removal of fiber coupled with fine grinding results in a considerably higher availability of grain energy for use by the body.
Wheat | Rice | |||||
---|---|---|---|---|---|---|
Whole | Refined | Enriched | Whole | Refined | Enriched | |
Calories | 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% |
B1 - Thiamin | 100% | 27% | 176% | 100% | 17% | 144% |
B2 - Riboflavin | 100% | 19% | 230% | 100% | 53% | 53% |
B3 - Niacin | 100% | 20% | 93% | 100% | 31% | 82% |
B5 - Pantothenic Acid | 100% | 43% | 43% | 100% | 68% | 68% |
B6 - Pyridoxine | 100% | 13% | 13% | 100% | 32% | 32% |
B9 - Folate | 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% |