Refined grains facts for kids
Grains like wheat, rice, and corn are an important part of our diet. When we talk about refined grains, we mean grain products that have been changed a lot from their natural state. Think of it like taking a whole apple and peeling off its skin and removing the core.
Contents
What Are Refined Grains?
Grains naturally have three main parts:
- The bran: This is the outer layer. It's full of fiber, B vitamins, and minerals.
- The germ: This is the part that could sprout into a new plant. It has B vitamins, Vitamin E, and healthy fats.
- The endosperm: This is the biggest part. It's mostly carbohydrates (starch) and some protein.
When grains are "refined," the bran and germ are usually removed. This is often done by grinding the grain or sifting it. After this, the grain might be mixed, bleached, or treated in other ways.
Why Are Grains Refined?
Refining grains makes them last longer on shelves because the oils in the germ can go bad over time. It also gives them a finer texture and a different taste that many people prefer. For example, white bread and white rice are made from refined grains.
What Happens to Nutrients?
When the bran and germ are removed, many important nutrients are lost. These include fiber, iron, and several B vitamins like thiamin, riboflavin, and niacin.
To make up for some of these losses, food companies often "enrich" refined grain products. This means they add back some of the vitamins and iron that were removed. However, even with enrichment, refined grains usually don't have as many nutrients as whole grains. For example, fiber is rarely added back during enrichment.
A Special Case: Corn and Nixtamalization
There's a special way corn is refined called nixtamalization. This is a chemical process where corn is soaked and cooked in an alkaline solution (like limewater). This process actually makes a nutrient called niacin much easier for our bodies to use. This is very important because it helps prevent a disease called pellagra, which can happen if people eat a lot of corn but don't get enough niacin.
Comparing Refined and Whole Grains
The table below shows how refining changes the nutrients in wheat and rice. The numbers are percentages compared to the whole grain (which is 100%). You can see that many nutrients drop a lot when grains are refined. When they are "enriched," some nutrients like thiamin, niacin, and iron are added back, sometimes even more than in the original whole grain. But others, like fiber, vitamin E, and magnesium, stay low.
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% |