Versatility and Impact of Milled Grain

Whole grains are often favored by health-conscious individuals due to their nutritional benefits. However, milled grains, though often criticized for their potential role in obesity, offer their own advantages and applications.

Milling grains not only extends their shelf life by removing the outer layers rich in fats prone to rancidity but also facilitates their incorporation into various food products. The by-products of milling, while sometimes used in animal feed, contribute to minimizing waste.

The resulting flour from milling serves as a key ingredient in a plethora of culinary creations. From bread and pasta to desserts and dumplings, the versatility of milled grain flour is undeniable. Additionally, flour derived from sources like potatoes, chestnuts, and pulses further expands the diversity of options available for culinary exploration and dietary needs.
Versatility and Impact of Milled Grain

Teff flour

Teff Flour comes from a gluten free ancient grain that originated in Ethiopia. Teff flour has a favorable nutrient profile. It is high in dietary fiber and protein and contains more nutrients per serving than all-purpose flour.

Teff is a type of grain that comes from a species of lovegrass (Eragrostis tef) or Williams’ lovegrass that is native to the Horn of Africa. It is an ancient grain believed to have been domesticated around 4000 and 1000 BC. Whole teff grain is a staple grain in Ethiopian diets.

Teff is a nutritional powerhouse. It is the smallest grain in the world—about 100 grains of teff are the size of a single kernel of wheat.

Its edible seeds which are roughly the size of poppy seeds and come in a variety of colors ranging from white to red to dark brown. These seeds are typically ground into flour and used to make a variety of baked goods including the traditional bread known as injera, a fermented pancake-like bread.

Compared to other grains, it has a much larger percentage of bran and germ so it's a very good source of dietary fiber, protein, iron, amino acids, vitamin C and calcium. Another teff flour benefit is the calcium content that significantly surpasses that of all other grains. Teff contains 20% to 40% resistant starches and has a low glycemic index (GI) rating – this makes it a great choice for diabetics to help manage blood sugar.

Teff flour is naturally gluten free, making it a popular choice among people following a gluten-free diet. This includes individuals with celiac disease, non-celiac gluten sensitivity, and wheat allergy.
Teff flour

Nutrient rich buckwheat flour

Buckwheat is a plant that originates from Mongolia and belongs to the family Polygonaceae. The buckwheat seed is a dark brown or even dark black achen of triangular shape with a length of 4-9 mm and the mass of 1000 seeds in the range of 15-35 g.

Buckwheat flour mixed with rye flour is used for bread production. According to chemical composition the buckwheat and buckwheat flour are excellent sources of minerals and lysine.

The amino acid composition of buckwheat proteins is well balanced and of a high biological value, although the protein digestibility is relatively low. Buckwheat grains are an important source of microelements, such as: Zn, Cu, Mn, Se, and macroelements: K, Na, Ca, Mg. With 80% unsaturated fatty acids more than 40% are constituted by polyunsaturated fatty acid (PUFA).

The significant contents of rutin, catechins and other polyphenols as well as their potential antioxidant activity are also of significance to the dietary value.

The primary source of carbohydrates in buckwheat is starch, and its content generally varies from 65 to 75%of the dry matter. The buckwheat starch is slowly digestible compared to wheat starch that is generally fast digestible. Therefore, by combining wheat flour with buckwheat flour products are obtained that provide slow digestible starch, giving them special nutritional importance, having similar effects to those of dietary fibers (prevention of colon cancer, lowering the glycemic index, could be nutritionally important diabetics).

Buckwheat is cultivated today primarily because of the grain, which is usually processed into flour after peeling the grain, and be prepared and used in different ways in different countries.

Specialties from buckwheat flour are pancakes and pie, while fried grain of buckwheat- porridge, is used as traditional dish in eastern Europe. In Japan usually are prepared slices of buckwheat. In Europe and North America usually buckwheat flour is mixed with wheat flour for preparation of pancakes, biscuits, chips.

Nutrient rich buckwheat flour 

Milling in ancient Egypt

Neolithic Egyptians developed bread from emmer, barky, and even a type of millet. The grain was stored in beehive-shape silos until needed and they ground the grain on flat stones called querns and then baked in and oven or in heated clay bread molds.

Both men and women assisted in making bread, with men performing many of the tasks. Women generally were the millers. Figures of women milling grain have been found in the tombs of the later Old Kingdom (c.2575-2510 BC) to early Middle Kingdom (c.2030-1640 BC).

Milling itself was a tedious process and the cause of many injuries. Several handfuls were place on a stone quern with a gently curve surface for milling. The upper surface is not perfectly smooth, but is kept somewhat roughed. A stone shaped like rolling pin with a curve to match the curvature of the grinding surface was rolled back and forth, grinding the grain into flour, which was caught in a container at one end of the quern.

The miller kneeled over on the ground, grinding on the wide saddle quern; then in the Middle Kingdom, the milling process was performed on workbenches. The rotary quern was not invented until about the fifth to third centuries BC, somewhere in the western Mediterranean.
Milling in ancient Egypt

Flour from heavy frosted wheat

Frost can be a fairly common occurrence in the temperate wheat-growing regions. If a number of frosted grains present, it will make the wheat work a little uncertainty, while the sound wheat is not of such high quality and natural weight. The grains are duller and lack the bright, clear, handsome appearance characteristic of the best grade.

As the degree of frost damage increases, wheat kernels become harder; flour yield decreases; starch damage increases; and because the bran becomes tightly adhered to the endosperm and is difficult to remove, flour ash content increases and flour become darker, reducing the overall flour yield potential.

Frosted wheat, when the entire see coat is badly affected produces a flour of poor dough quality. Flour produce from heavy frosted grain produces bread of lower loaf volume, poorer texture and darker color. The flour yield from such grain is reduced and the ash content is likely to be abnormally high.
Flour from heavy frosted wheat

What is the most suitable flour for making noodles?

Classification of wheat flour is based on grain properties such as softness/hardness, winter, spring growth habit, red/white bran and protein content.

Starch and protein, two major components of wheat flour, largely determine the processing and product quality of many wheat-based foods, not only because of their proportions in wheat four, but also due to their wide variations in functional properties.

Middle-wheat flour is best suited for noodles, hard and semi hard wheat flours are best for bread and soft-wheat flour is used when making a cake.

In Asian noodles, physicochemical and characteristics of starch and protein may play a much bigger role in processing and product quality than in any baked products including bread, cookies, cakes and pastries.

Wheat flour with ~ 10% protein content is considered suitable for white salted noodle-making. A positive relationship has been reported between protein content and textural properties of noodles.

Water absorption for making noodles, dough mixing, and sheeting, frying and cooking, as well as texture of cooked noodles are all largely governed by the quantitative and qualitative characteristics of starch and protein.

Flour from medium-hard wheat genotypes with low ash content, high flour whiteness, medium protein content, medium to strong gluten type and good starch viscosity is considered suitable for making Chinese noodles.
What is the most suitable flour for making noodles?

Organic flour

Organic flour is from wheat and other grains that are grown without chemicals; the designation ‘organic’ for flour is not standardized because it varies from state to state.

According to the United States Department of Agriculture (USDA), products labeled ‘organic’ may likely contain a lower level of pesticide contamination that conventionally grown foods: but there is not an absolute guarantee that they are completely free of pesticides.

Organic flour is grown and stored without the use of synthetic herbicides or insecticides. No toxic fumigants may be used to kill pests in the grain and no preservatives may be added to the flour, packaging or food product.

Organic flours have their benefit and nutrition but are heavier and drier to bake with. They simply do not have the gluten, i.e. body sand structure, on their own to provide the loft and crumb the people accustomed to when baking with white flour.

These organic grains greatly benefit when combined with some unbleached all-purpose flour, which provides structure to baked goods.
Organic flour

Buckwheat used as food

Cooked and roasted buckwheat grains a good source of magnesium; they also contain potassium, copper, zinc, phosphorus, folic acid, iron and panthotenic acid. Most of the buckwheat grain utilized as human food is sold in the form of groats and flour.

Groats are of white, beige, light brown or dark brown colour, depending on the method of hulling. The color of buckwheat four is darker than wheat flour due to a higher crude fiber content and because the hull fragment cannot to be totally removed by the direct milling of the grain.

Buckwheat seeds

The main product is the grain which is widely used for flour and porridge and in a wide range of cooked products such biscuits, noodles, pancakes and ready to eat breakfast cereals. The chief food use of buckwheat in the United States and Canada is griddle cakes made from the flour, often mixed with wheat flour.

Buckwheat cakes are brown, palatable, and nutritious. Buckwheat is very suitable for replacing rice, and it is used as a popular replacement for rice in white or black pudding preparations.

Buckwheat cake

It is used in its hulled grain form for enriching soup, in industrial meat products (sausages) and slice cold sausages It can also be used for decoration of foods. In Japan, 10 – 50% what flour is added to buckwheat flour, and the mixture to make Soba or buckwheat noodles.

In India flour from the grain is staple food used for making ‘chillare’ an unleavened bread. Buckwheat grain is also fed to livestock. In England, buckwheat is a popular feed for pheasants.
Buckwheat used as food

Rye flour

Rye is a cereal grass that is second only to wheat on world popularity for bread baking. It has a storing, hearty flavor in bread and as a cereal.

Rye flour is commercially ground to a range of colors and particles sizes. It is a gluten containing flour, although it is lower in gluten than wheat. Commercial rye four generally with rye-flour from the centre of the endosperm; cream or light rye flour includes the next layer; and dark rye flour includes the outside of the endosperm.

Light rye: The lightest is nearly white. It has a very fine texture and high percentage of starch, with little protein.

Dark rye: Like clear flour milled from wheat, dark rye comes from the part of the rye grain closest to the bran. Thus, it is darker than other rye flours and has a lower percentage of fine starch particles.

Rye flour makes delicious robust bread. It does not however, respond favorably to commercial yeast, so some wheat flour must be added to dough to enable the yeast to develop. Typical formulas call for 25 to 40% rye flour and 60 to 75% hard wheat four.
Rye flour

Corn flour

Corn is a primary ingredient for corn collets and many pellet products.  Cornmeal, corn grits, corn flour and corn cones are all a different form of dry-milled dent corn, and in general vary only in particle size distribution.

Corn meal which has been leached with lye is called masa harina and is used to make tortillas and tamales in Mexican cooking.

Corn flour, a finer form of corn meal, is yellow four milled form corn. It is very popular in the southern United States and in Mexico. Coarse whole-grain corn flour is usually called corn meal.

Corn flour on its own produces a denser, drier product because it absorbs greater amount of liquid due to the higher carbohydrate content and the type of carbohydrate.

It adds strength to dough and batters and a nice depth of flavor. It tastes sweet, and slightly nutty.
The flour can be used in all baked goods such as breads, tortilla, muffins, loaves, cakes, biscuits, pancakes, crepes, waffles, cookies, pie dough and pasta.

Corn flour is suitable for yeast bread baking when used in conjunction with wheat flour.
Corn flour

Rye flour

Rye is a cereal grass that is second only to wheat in world popularity for bread baking. It has as strong hearty flavor in bread and as a cereal. Most rye is roller milled, though stone milling on the industrial scale was utilized for rye longer than for wheat into the 1920s in some countries.

Because rye is so hydroscopic, the gain requires less tempering before it is milled. Rye four is a gluten-containing flour although it is lower in gluten than wheat. Whole grain rye flour produces dense but very flavorful breads.

Rye flour is commercially ground to a range of colors and particles sizes and various nomenclature:
*White rye flour
Rye flour that consist only the center of the endosperm is known as white rye flour. Rye flour lacks many of the original nutrients found in the kernel. It is the rye flour with bran and germ removed. This flour is a good choice for these on low fiber diets.

*Light rye flour or cream
Inclusion of small traces of bran in white rye flour makes it into light rye flour or cream. The lightest is nearly white. It has very fine structure and high percentage of starch, with little protein.

*Medium rye flour
If more bran is included in the white rye flour, medium rye flour is obtained which has many of the original characteristics of the rye.

*Dark rye flour
Dark rye flour is sometimes also referred to as whole grain flour.  Dark rye comes from the part of the rye grain closest to the bran. Thus, it is darker than other rye flours and has lower percentage of fine starch particles.

*Rye meal
This is the best term for whole grain rye flour. Rye meal contains the bran, endosperm and germ of the original rye berry; it can be ground to fine, medium or coarse levels.

*Pumpernickel
Coarse, whole grain rye flour is known as pumpernickel. It is also the name of the traditional German bread.

Rye four makes delicious robust bread. It does not, however, respond favorably to commercial yeast, so wheat flour must be added to the dough to enable the yeast to develop.
Rye flour  

Graham flour

When wheat is simply reduced to a meal by grinding it once or twice and not removing it any bran, etc, it is known as Graham flour.

Graham flour contains all of the constituents of the wheat grain in their natural proportions. This type of flour has some advantages from the point of view of food value over a flour that does not contain the bran and the germ.

Graham Flour

Graham Flour Named after whole grain proponent Sylvester Graham in the late nineteenth century.

Graham flour is normally used in Canada for making yeast rolls and loafs, quick breads and also cakes. The flour is very popular and healthy wheat flour eaten extensively in Canada in the 60s, and in the US, it now marketed as a coarsely ground whole wheat flour, which is stone-ground.

Normally, Graham fours, which are made for making quick bread laves and rolls are mixed with white flour as to get the best of both worlds. Graham flour makes lighter bread, the whole wheat.
Graham flour

Pseudocereal of buckwheat

Buckwheat belongs to the family Polygonaceae. Common buckwheat (Fagopyrum esculentum Moench) has been a crop of secondary importance in many countries.

It has persisted through centuries of civilization and enters into the agricultures of nearly every country where cereals are cultivated. Buckwheat is a plant cultivated for its grain-like seeds and also used as a cover crop. Despite the name, buckwheat is not related to wheat, as it is not a grass.

This plant makes an aromatic flower and subsequently the buckwheat groats which are small triangle-shaped grain-like seeds covered by a hard shell.

In the United States the two buckwheat varieties are the common and Tartary types. The color can be anywhere from a tan-pink hue to brown. Buckwheat so also sold as roasted kasha, which is known for its subtler flavor.

Tartary buckwheat is known in various localities under such names as Duckwheat, Rye buckwheat, Marino, Mountain, Siberian, Wild Goose, Hull-less and Bloom-less.

The seed of buckwheat is cooked like rice or made into flour for the preparation of noodles, pancakes, porridge, cakes and biscuits.
Pseudocereal of buckwheat

Glutenin in flour

Flour itself does not contain gluten. One of gluten’s main protein fractions in the flour is gliadin which a complex mixture.

At least forty different components may be identified in a single wheat variety. Gluten’s other main protein fraction is glutenin.

Glutenin are protein polymers consisting of high and low molecular weight glutenin subunits HMW-GS and LMW-GS linked though disulphide bonds.

The polymeric glutenin protein have molecular sizes ranging up into the tens of millions of Daltons. The great length of these chains is presumed to confer in wheat its unique dough forming properties.

Glutenin is thought to provide most of the strength also called tenacity, to gluten, while gliadin provides its stretchiness or extensibility. Glutenin also provides elasticity to gluten; that is its ability to bounce back one it is stretched or pressed.

The network of glutenin and gliadin is formed when the long glutenin molecules cross link with hooks on the globular gliadin molecules.

This network is very stretchy and liable, and it appears that the combination of gliadin and glutenin responsible for gas retention in wheat four dough.

The stretchiness lets the dough structure hold on the gas of carbon dioxide, which is produced by yeast or baking powder and form the crumb or texture of the bread.

In cases of gluten intolerance, the gliadin fraction is the cause of the symptoms; the glutenin fraction is not.
Glutenin in flour

Gliadin in wheat flour

Gliadin is a heterogeneous group of prolamines. They are rather hydrophobic, hence their insolubility in water or salt solutions. They are single chain proteins and such disulfide bonds that occur are all intra-molecular. 

Gliadin is the major storage protein in wheat. Wheat flour has a total protein content of about 10% and approximately 10% of these proteins are made up of alcohol soluble gliadin proteins.

Gliadin is practically as abundant in the wheat kernel. The proportion of gliadin in wheat flour has much to do with its quality for bread making purpose. It is said that gliadin gives tenacity and elasticity to the gluten, while glutenin gives strength; but the two proteins must be present in proper protein of the gluten is to have the properties desired in bread-making.

In order to make a large light loaf of bread, the flour should have a fairly high gluten content and its gluten should contain a high proportion of gliadin.
Gliadin in wheat flour

Flour for baking cakes

The type of flour used for baking cake defines its flavor and texture. The chemical composition of this flour is ideal for cake making.

Cake flour contains less protein about 8% and more starch than all purpose flour and holds less water. It is low in gluten forming potential, is highly bleached and finely milled. It is made with soft wheat.

The low content of gluten help hold the evenly distributed air bubbles in the batter, makes light textured, tender cakes and biscuits.

Without cake flour, the cakes would not rise, or more likely they would rise and then collapse during baking and cooling.

By using cake flour, during late stages of baking, starch granules gelatinizes to set structure. The starch granules absorb water and swell then thicken batters, even as large amount of water and sugar added.

Rice flour is the most common substitute for wheat flour in cake recipes. If it is used alone in a recipe, however, rice flour will make for a gritty cake texture. Grittiness can be eliminated by combining the rice flour with other flours.

Flour for baking cakes

All purpose flour

All-purpose flour combines the desirable qualities of both hard and soft wheat flour. It does not contain bran or germ and is known as white wheat flour, or simply ‘flour’.

To make flour pure white, it is treated chemically with chlorine dioxide, benzoyl peroxide and acetone peroxide.

It forms less strong and elastic dough than bread flour and it may be enriched or bleached. All purpose flour contains slightly less protein than unbleached.

Many bakers prefer to use bleached flour for cakes, cookies and pastries because they say the result are more delicate.

As its name implies, can be used for many purposes, including baking, thickening and coating. All purpose flour usually is sold pre-sifted and is available bleached or unbleached.

All purpose flour is a blend of flours and each company has its own trademark style and protein content for its all purpose flour.
All purpose flour

Milling process of wheat

The single term ‘milling’ applied in the context of cereals, covers a wide range of processes. In general they are methods of transforming whole grains into forms suitable for consumption or for conversion into consumable products.

The conventional milling process of wheat first involves washing to remove foreign substance such as dirt or rocks.

Milling is a process by which kernel components are separated physically or chemically.

Once the endosperm is separated it subsequently is ground multiple times in reduction rolls to become finer and finer for flour.

As the bran and germ are removed, the refined flour contains streams that contain less vitamins and minerals.

If flours streams of the endosperm are blended during the milling process various flours are created.

Other products of the process, e.g. vital gluten, can supplement other edible products. Millfeeds, the material remaining after all the usable flour is extracted is used by the feed industry either directly or as a feed supplement.
Wheat milling practices might cause significant differences in flour quality, which are due to flour particle size, extraction rate, and the level of starch damage.

In general, 100 pounds of wheat will produce 72 pounds of flour. The remaining 28 pounds is classified as millfeed.
Milling process of wheat

Wheat Flour

Wheat Flour
High protein flour is desirable for some types of baked products, flour of moderate protein content for others, and high starches low protein content flour is desirable for still other baked foods.

The smaller flour particles are higher in proteins; the larger flour particles are higher in starch. Through air classification in a turbomill it is possible to separate flour particles into various size, which can be blended to provide whatever protein or starch content is required by the baker or other users of flour.

Turbomilling developed in the late 1950s, is considered to be significant milling innovation, because only through this process is the variety of blends for different products possible.

In the United States, wheat flour is enriched with the mineral, iron (as a salt). Enrichment with calcium salts is optional for some types of flour but mandatory for enriched, self-rising flour.

Wheat flour is use to make leavened products, such as alimentary pastes (macaroni, spaghetti, noodles, etch. Cake mixes are also prepared with flour, and flour is used for thickening canned and homemade stews, soups gravies and white sauces.

Various breakfast cereal products are made from wheat. Generally, in these products, the wheat is precooked an passed though heated rolls to form flakes.

It may also be shredded, or it may be heated to above the boiling point of water under pressure, with puffed wheat formed when the pressure is released.

Wheat bran may also be produced as flakes. High protein cereals may be produced from wheat together with added wheat starch sugar malt, minerals (such as phosphates), vitamins and other ingredients.

Some wheat flakes are coated with very thin layers of sugar.
Wheat Flour

Wheat Grain Processing

Wheat Grain Processing
Wheat is harvested by combines that cut the stalk remove and collect the seed, and either return the straw to the soil, to be plowed under with the stubble and thus provide hummus or compress and bale it for future use as litter, ensilage and so on.

Wheat may be bagged in jute sack and stored in warehouses or it may be stored in bulk in elevators. The latter method provides the best protection against rodent and insect infestation.

The moisture content of bulk stored wheat should not be higher than 14.5% and that of sack stored wheat not higher than 16%. Otherwise, microorganism may grow and cause heating and spoilage. When it is necessary to lower the moisture content of wheat it may be dried in bins by blowing hot air (not higher in temperature than 175 degree F) across the bins.

In preparing wheat for milling, it is blown into hopper scales that record the quantity of uncleaned wheat. Some of the coarser impurities are removed by this process. The grain then passes over a series of coarse and fine sleeves that further remove contaminating materials, including chaff and straw. Still in dry states stones may be removed by passing wheat over short openings that allow the heavier stones to fall out of mass and be trapped.

The wheat is next passed over discs or cylinders containing indented surface that remove seeds short or longer than wheat following a pass through a magnetic separator to remove any metals present. The next cleaning process is dry scouring to remove adhering dirt.

The wheat is then washed in water, a process that both removes dirt and adds 2 – 3% water to the grain. The added water is necessary to provide desirable conditions for milling. A stone trap is including in the washer. Excess water is removed by centrifugation. A second wet cleaning with a light brushing action is ordinarily used, followed by aspiration (blowing air through the grain), which is the final cleaning operation.

The grain is then carried into a bin from which it is fed to the milling operation. This bin is located on the top floor of the flour mill, the grain having been elevate do this position during the various cleaning operation.

In milling, grain is fed automatically though scale hoppers that regulate the flow of the seeds at rates corresponding to those of the following operations:

Milling may be carried out by passing the grain through a series of corrugated rolls rotating toward each other, which remove chunks of the endosperm from the bran. After each passage through the break rolls, the material is sifted through cloth, or wire sieve and separated according to particle size.

The various streams of different sized flour particles are finally blended to provide the different grades of flour. The more finely ground flour is nearer to white but less nutritious than the coarser ground flour.

This results from the more effective removal of bran and germ from finely ground flour. Impact milling is now used in some operations. With this method, the seed is broken open by impact in a machine. Flour particles of different sizes are separated by air classification or by centrifugation.
Wheat Grain Processing