The germ of a cereal grain is the part that develops into a plant; [1] it is the seed embryo. [2] Along with bran, germ is often a by-product of the milling [3] that produces refined grain products. Cereal grains and their components, such as wheat germ oil, [4] rice bran oil, and maize bran, [5] may be used as a source from which vegetable oil is extracted, or used directly as a food ingredient. The germ is retained as an integral part of whole-grain foods. [6] Non-whole grain methods of milling are intended to isolate the endosperm, which is ground into flour, with removal of both the husk (bran) and the germ. Removal of bran produces a flour with a white rather than a brown color and eliminates fiber. The germ is rich in polyunsaturated fats (which have a tendency to oxidize and become rancid on storage) and so germ removal improves the storage qualities of flour. [7]
Nutritional value per 100 g (3.5 oz) | |
---|---|
Energy | 1,598 kJ (382 kcal) |
51.8 g | |
Sugars | 7.8 g |
Dietary fiber | 15.1 g |
10.7 g | |
Saturated | 1.83 g |
Monounsaturated | 1.5 g |
Polyunsaturated | 6.62 g |
29.1 g | |
Vitamins | Quantity %DV† |
Thiamine (B1) | 145% 1.67 mg |
Riboflavin (B2) | 68% 0.82 mg |
Niacin (B3) | 35% 5.59 mg |
Pantothenic acid (B5) | 28% 1.387 mg |
Vitamin B6 | 75% 0.978 mg |
Folate (B9) | 88% 352 μg |
Vitamin C | 7% 6 mg |
Vitamin E | 107% 15.99 mg |
Minerals | Quantity %DV† |
Calcium | 5% 45 mg |
Iron | 70% 9.09 mg |
Magnesium | 90% 320 mg |
Manganese | 950% 19.956 mg |
Phosphorus | 164% 1146 mg |
Potassium | 32% 947 mg |
Zinc | 175% 16.67 mg |
†Percentages estimated using US recommendations for adults. [8] |
Wheat germ or wheatgerm is a concentrated source of several essential nutrients, including vitamin E, folate (folic acid), phosphorus, thiamin, zinc, and magnesium, as well as essential fatty acids and fatty alcohols. [9] [10] It is a good source of fiber. [11] White bread is made using flour that has had the germ and bran removed. [12] Wheat germ can be added to protein shakes, casseroles, muffins, pancakes, cereals, yogurt, smoothies, cookies, and other goods. [13] Wheat germ can become rancid if not properly stored in a refrigerator or freezer [14] and away from sunlight. [15] Some manufacturers prevent rancidity by storing wheat germ in vacuum-sealed glass containers, or by placing an oxygen-absorbing sachet inside air-tight packaging.
In molecular biology, wheat germ extract is used to carry out cell-free in vitro translation experiments since the plant embryo contains all the macromolecular components necessary for translating mRNA into proteins but relatively low levels of its own mRNA. [16] [17]
Wheat germ is also useful in biochemistry since it contains lectins that bind strongly to certain glycoproteins; therefore, it can be used to isolate such proteins.
The embryo is that part of the seed that germinates and grows into the vegatative plant. In cereal grains, embryos (germs)...
...the germ or embryo of the grain...
There are two methods that are used for the dry-milling process: milling without removal of the cereal germ, the oldest method, and milling with removal of the cereal germ, the method most used today to ensure a better preservation.
Table: Vegetable Oil Stability [includes wheat germ]
In addition, some maize and rice bran are used to make vegetable oil.
Whole-grain flours are typically stone-ground or hammer-milled. Refined flours, from grains stripped of their bran and germ, must be milled with rollers.
Table 3.4. Nutritional Components of Wheat Germ, Soy, Egg Yolk, Broccoli Florets, and Beef Liver
...the germ is a highly concentrated source of nutrients, including niacin, thiamin, riboflavin, vitamin E, folate, magnesium, phosphorus, potassium, iron and zinc. The germ also contains protein, fibre and some fat.
Fibre... whole grains contain it, and wheat germ is an especially good source.
...ordinary white flour (and white bread made from it) contains no bran, germ, or semolina...
People who choose to add wheat germ to their food often incorporate it into casseroles, muffins, and pancakes or sprinkle it over cereal or yogurt. The texture of wheat germ can add a great crunchiness and taste to these foods in a very convenient way.
Always keep opened wheat germ in the refrigerator to prevent rancidity.
Carrier oils also turn rancid over an extended period of time and deteriorate with excess exposure to sunlight and oxygen. Most carrier oils like wheat germ... have a shelf life of eight to ten months.
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize. Edible grains from other plant families, such as buckwheat and quinoa are pseudocereals. Most cereals are annuals, producing one crop from each planting, though rice is sometimes grown as a perennial. Winter varieties are hardy enough to be planted in the autumn, becoming dormant in the winter, and harvested in spring or early summer; spring varieties are planted in spring and harvested in late summer. The term cereal is derived from the name of the Roman goddess of grain crops and fertility, Ceres.
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many cultures. Corn flour has been important in Mesoamerican cuisine since ancient times and remains a staple in the Americas. Rye flour is a constituent of bread in both Central Europe and Northern Europe.
Breakfast cereal is a breakfast food made from processed cereal grains. It is traditionally eaten as part of breakfast, or a snack food, primarily in Western societies.
Bran, also known as miller's bran, is the hard layers of cereal grain surrounding the endosperm. It consists of the combined aleurone and pericarp. Corn (maize) bran also includes the pedicel. Along with the germ, it is an integral part of whole grains, and is often produced as a byproduct of milling in the production of refined grains.
The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid in most species, which may be auxin-driven. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in animal diet. For example, wheat endosperm is ground into flour for bread, while barley endosperm is the main source of sugars for beer production. Other examples of endosperm that forms the bulk of the edible portion are coconut "meat" and coconut "water", and corn. Some plants, such as orchids, lack endosperm in their seeds.
White bread typically refers to breads made from wheat flour from which the bran and the germ layers have been removed from the whole wheatberry as part of the flour grinding or milling process, producing a light-colored flour.
Wheat flour is a powder made from the grinding of wheat used for human consumption. Wheat varieties are called "soft" or "weak" if gluten content is low, and are called "hard" or "strong" if they have high gluten content. Hard flour, or bread flour, is high in gluten, with 12% to 14% gluten content, and its dough has elastic toughness that holds its shape well once baked. Soft flour is comparatively low in gluten and thus results in a loaf with a finer, crumbly texture. Soft flour is usually divided into cake flour, which is the lowest in gluten, and pastry flour, which has slightly more gluten than cake flour.
Enriched flour is flour with specific nutrients added to it. These nutrients include iron and B vitamins. 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.
A whole grain is a grain of any cereal and pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm.
Corn kernels are the fruits of corn. Maize is a grain, and the kernels are used in cooking as a vegetable or a source of starch. The kernel comprise endosperm, germ, pericarp, and tip cap.
Species belonging to the genus Amaranthus have been cultivated for their grains for 8,000 years. Amaranth plants are classified as pseudocereals that are grown for their edible starchy seeds, but they are not in the same botanical family as true cereals, such as wheat and rice. Amaranth species that are still used as a grain are Amaranthus caudatus L., Amaranthus cruentus L., and Amaranthus hypochondriacus L. The yield of grain amaranth is comparable to that of rice or maize.
Refined grains have been significantly modified from their natural composition, in contrast to whole grains. The modification process generally involves the mechanical removal of bran and germ, either through grinding or selective sifting.
Wheat middlings are the product of the wheat milling process that is not flour. A good source of protein, fiber, phosphorus, and other nutrients, they are a useful fodder for livestock and pets. They are also being researched for use as a biofuel.
Sprouted bread is a type of bread made from whole grains that have been allowed to sprout. There are a few different types of sprouted grain bread. Some are made with additional added flour; some are made with added gluten; and some, such as Essene bread and Ezekiel bread are made with very few additional ingredients.
A Unifine mill is a single one-pass impact milling system which produces ultrafine-milled whole-grain wheat flour that requires no grain pre-treatment and no screening of the flour. Like the grist or stone mills that had dominated the flour industry for centuries, the bran, germ, and endosperm elements of grain are processed into a nutritious whole wheat flour in one step. Consumers had accepted whole wheat products produced by grist or stone mills. The flour produced by these mills was quite coarse as they included the bran and the germ elements of the grain.
A staple food, food staple, or simply staple, is a food that is eaten often and in such quantities that it constitutes a dominant portion of a standard diet for an individual or a population group, supplying a large fraction of energy needs and generally forming a significant proportion of the intake of other nutrients as well. For humans, a staple food of a specific society may be eaten as often as every day or every meal, and most people live on a diet based on just a small variety of food staples. Specific staples vary from place to place, but typically are inexpensive or readily available foods that supply one or more of the macronutrients and micronutrients needed for survival and health: carbohydrates, proteins, fats, minerals, and vitamins. Typical examples include grains, seeds, nuts and root vegetables. Among them, cereals, legumes and tubers account for about 90% of the world's food calorie intake.
Whole-wheat flour or wholemeal flour is a powdery substance, a basic food ingredient, derived by grinding or mashing the whole grain of wheat, also known as the wheatberry. Whole-wheat flour is used in baking of breads and other baked goods, and also typically mixed with lighter "white" unbleached or bleached flours to restore nutrients, texture, and body to the white flours that can be lost in milling and other processing to the finished baked goods or other food(s).
The Roller Mill was created by Hungarian bakers in the late 1860s and its popularity spread worldwide throughout the 1900s. Roller mills now produce almost all non-whole grain flour. Enriched flour is flour that meets an FDA standard in the United States. Roller milled white enriched flour makes up over 90% of the flour that comes out of the United States.
Flour extraction is the common process of refining Whole Grain Flour first milled from grain or grist by running it through sifting devices, often called flour dressers.
Rice is commonly consumed as food around the world. It occurs in long-, medium-, and short-grained types. It is the staple food of over half the world's population.