OAT- AN IMPORTANT CEREAL
DR. S. M. ALAM
Nov 21 - 27, 2011
Oats, known scientifically as Avena sativa, are a hardy cereal grain able to withstand poor soil conditions in which other crops are unable to thrive. Oats gain part of their distinctive flavor from the roasting process that they undergo after being harvested and cleaned. Although oats are then hulled, this process does not strip away their bran and germ allowing them to retain a concentrated source of their fiber and nutrients.
Oats have numerous uses in food; most commonly, they are rolled or crushed into oatmeal, or grounded into fine oat flour.
Oatmeal is chiefly eaten as porridge, but may also be used in a variety of baked goods such as oatcakes, oatmeal cookies, and oat bread. Oats are also an ingredient in many cold cereals, in particular muesli and granola.
Oats may also be consumed raw, and cookies with raw oats becoming popular. Oats are also occasionally used in several different drinks. In Britain, they are used for brewing. A cold, sweet drink made of ground oats and milk is a popular refreshment throughout Latin America. Oatmeal caudle, made of ale and oatmeal with spices, was a traditional British drink and a favorite of Oliver Cromwell.
Oat bread was first manufactured in England, where the first oat bread factory was established in 1899. In Scotland, they were, and still are, held in high esteem, as a mainstay of the national diet. In Scotland, a dish called sowans was made by soaking the husks from oats for a week so that the fine, floury part of the meal remained as sediment to be strained off, boiled, and eaten.
Oats are also widely used there as a thickener in soups, as barley or rice might be used in other countries. Oats are also commonly used as feed for horses - as crimped or rolled oats or as part of a blended food pellet.
The oat hull must be crushed ("rolled" or "crimped") for the horse to digest the grain. Cattle are also fed oats, either whole, or ground into a coarse flour using a roller mill, burr mill or hammer mill.
Oat extract can also be used to soothe skin conditions. It is the principal ingredient for the Aveeno line of products. Oat grass has been used traditionally for medicinal purposes, including to help balance the menstrual cycle, treat dysmenorrhea and for osteoporosis and urinary tract infections.
Oats are generally considered "healthy", or a health food, being touted commercially as nutritious. The discovery of the healthy cholesterol-lowering properties has led to wider appreciation of oats as human food. Oat bran is the outer casing of the oat. Its consumption is believed to lower cholesterol, and possibly reduce the risk of heart disease.
Oats contain more soluble fibre than any other grain, resulting in slower digestion and an extended sensation of fullness. One type of soluble fibre, beta-glucans, has proven to help lower cholesterol. After reports of research finding that dietary oats can help lower cholesterol, an "oat bran craze" swept the U.S. in the late 1980s, peaking in 1989, when potato chips with added oat bran were marketed.
The food fad was short-lived and faded by the early 1990s. The popularity of oatmeal and other oat products again increased after the January 1998 decision by the Food and Drug Administration (FDA), when it issued its final rule allowing a health claim to be made on the labels of foods containing soluble fibre from whole oats (oat bran, oat flour and rolled oats), noting that three grams of soluble fibre daily from these foods may reduce the risk of heart disease.
To qualify for the health claim, the whole oat-containing food must provide at least 0.75 grams of soluble fibre per serving. The soluble fibre in whole oats comprises a class of polysaccharides known as beta-D-glucans.
Beta-D-glucans, usually referred to as beta-glucans, comprise a class of indigestible polysaccharides widely found in nature in sources such as grains, barley, yeast, bacteria, algae and mushrooms. In oats, barley and other cereal grains, they are located primarily in the endosperm cell wall.
Oat beta-glucan is a soluble fibre. It is a viscous polysaccharide made up of units of the monosaccharide D-glucose. Oat beta-glucan is composed of mixed-linkage polysaccharides.
Oats, after corn, have the highest lipid content of any cereal, e.g., greater than 10 percent for oats and as high as 17 percent for some maize cultivars compared to about two to three percent for wheat and most other cereals. The polar lipid content of oats (about 8-17 per cent glycolipid and 10-20 per cent phospholipid or a total of about 33 per cent) is greater than that of other cereals, since much of the lipid fraction is contained within the endosperm.
Oats are the only cereal containing a globulin or legume-like protein, avenalin, as the major (80 per cent) storage protein. Globulins are characterized by solubility in dilute saline.
The more typical cereal proteins such as gluten and zein are prolamines. Oat protein is nearly equivalent in quality to soy protein, which has been shown by the World Health Organization to be equal to meat, milk, and egg protein. The protein content of the hull-less oat kernel ranges from 12 to 24 per cent, the highest among cereals.
Eating oats in our diet provides a wide range of important health benefits especially if we are dealing with diabetes or heart disease.
1. LOWERING OF CHOLESTEROL: Oatmeal and oat bran contain significant amount of dietary fiber. Out of which, half is soluble and the other half is insoluble fibers. Soluble fibre found in oats contains beta-glucans, which has been proven very effective in lowering blood cholesterol.
2. CONTROLLING DIABETES: Eating oats is known to stop rapid rise in blood sugar after the consumption as they are slow digesting. This is very important to control blood glucose and insulin levels, and helps to prevent many complications, which are associated with Type 2 diabetes.
3. HELPS IN CONTROLLING HYPERTENSION: A daily serving of whole oats rich in soluble fibre can reduce hypertension, or high blood pressure.
4. REDUCE THE RISK OF CARDIOVASCULAR DISEASE: Oats also contain phytochemicals, such as avenanthramides (a type of antioxidant). In a study conducted by Tufts University researchers, oats have been known to help prevent free radicals from damaging LDL cholesterol thereby reducing the risk of cardiovascular diseases.
5. IMPROVE DIGESTION: Oats are rich in both soluble and insoluble fiber. Fiber is essential in keeping bowel movements regular. It makes stools heavier and smooth which speeds up their passage through the gut, and helps in reliving constipation.
6. WEIGHT CONTROL: If you are watching your weight, oats can help you in just that. Oats contain soluble fiber and upon digestion, it forms a gel, which causes the viscosity of the contents of the stomach and small intestine to be increased. This delay in emptying your stomach makes you full for longer period and helps to combat frequent hunger.
7. GOOD SOURCE OF PROTEIN: Oats are rich in protein (One cup cooked oats have about 6g of protein) that is almost twice the amount in similar quantity of wheat flakes or other grains, and if you consume it with one cup hot milk, it adds to protein. That's why a bowl of hot oatmeal with milk keeps you full for longer times. Also, the quality of the protein is superior to the quality of protein found in wheat or other grains. Protein is used to build, repair, and maintain all body tissues and provide the body energy.
8. ANTIOXIDANT PROPERTIES: Oats are very good source of selenium which is a cofactor of the important oxidant glutathione peroxides. Selenium works with vitamin E as an oxidant and helps in decreasing asthma symptoms and prevention of heart disease. In addition to this, selenium also has been associated with reducing risk for cancer.