During the process of making flour nutrients are lost. Some of these nutrients are replaced during refining and the result is "enriched flour".
Enriched flour is flour with specific nutrients returned to it that have been lost while being prepared. These restored nutrients include iron and B vitamins (folic acid, riboflavin, niacin, and thiamine). Calcium may also be supplemented. The purpose of enriching flour is to replenish the nutrients in the flour to match the nutritional status of the unrefined product. This differentiates enrichment from fortification, which is the process of introducing new nutrients to a food.
Flour processing and nutrient loss
The conversion of grains to flour involves several steps that vary with the type of grain used. The initial stages of processing remove the bran and the germ of the seed. The bran is the outermost layer of grains that contains fiber (primarily insoluble), some protein, and trace minerals. The germ is the embryo of the seed that contains B vitamins and trace minerals. Because the germ has a fat content of 10%, it may reduce shelf-life. Thus, it is separated to ensure longer shelf life of the flour. In contrast to enriched flour, whole wheat flour contains both the bran and the germ. The remaining and largest portion of the seed is the endosperm. It acts as a nutrient reservoir for the developing embryo. The endosperm contains a large amount of carbohydrates, protein
, B vitamins (niacin and riboflavin), and soluble fiber.
Once the endosperm is isolated, it is ground into a fine powder and sifted to remove any remaining fragments of bran or germ. The final flour product contains a smaller portion of the original nutrients that were present in the seed prior to processing. Enrichment ensures that these important nutrients are restored to improve the quality of the flour.
According to the FDA, a pound of enriched flour must have the following quantities of nutrients to qualify: 2.9 milligrams of thiamin, 1.8 milligrams of riboflavin, 24 milligrams of niacin, 0.7 milligrams of folic acid, and 20 milligrams of iron. The first four nutrients are B vitamins. Calcium also may be added; this must be to a minimum level of 960 milligrams per pound if calcium is mentioned in the labeling.
There has been a lot of controversy regarding the benefits of enriched flour in relation to those of whole-wheat flour. Although enriched flour does contain the similar amounts of vitamins as the unrefined flour products, it does not have the same nutritional benefits of whole-wheat flour. One of the most significant differences is the amount of fiber. During the production of white enriched flour, a lot of the fiber-containing components (the bran and germ) are reduced or removed. Thus, products made from this type of flour contain smaller amounts of fiber than those made with whole-wheat flour. Another concern is the effect on blood sugar levels. Enriched flour products tend to be higher on the glycemic index, quickly raising blood sugar levels. In contrast, foods made from whole grains tend to be lower on the glycemic index. Because they contain higher amounts of fiber and other complex carbohydrates, they take longer to digest; therefore, sugars enter the bloodstream in a slow and more controlled manner. A diet containing primarily low glycemic index foods has been related to many health benefits: reduced cholesterol levels, reduced risk of heart disease, and healthy weight loss.
Low glycemic index is not due to fiber but more likely starch structure. Grinding wheat to a fine powder (flour) breaks this structure, creating a higher index. Wholemeal bread differs little from white bread. Grainy breads containing fragments of bran and germ have a lower glycemic index due to the fragments, while semolina has a lower index than flour.
Recipe using Enriched Flour see Here