Presented by Tamirat Kore

Agricultural Quality Research Laboratory, Addis Ababa

December 31, 2015

Introduction of wheat

Nutritional composition and health benefits of wheat

Types of wheat

Quality of wheat

Wheat milling process

Types of flour

Wheat products

Bread

Biscuits and cookies

Pasta, macaroni and cookies

Yeast raised doughnut

Wheat is the most important staple food crop for more than

one third of the world population

Globally, wheat is the leading source of vegetable protein in

human food, having higher protein content and more calories

than maize or rice, the other major cereals.

It is nutritious and easy to store and can be processed into

various types of food.

It is an excellent health building food

Wheat is considered as a good source of protein,

minerals, B-group vitamins and dietary fiber

Although the environmental conditions can affect

nutritional composition of wheat grain with its essential

coating of bran, vitamins and minerals.

Wheat grain is stable food used to make flour for

leavened, flat, and steamed breads, biscuits, cookies,

cakes, breakfast cereals, pasta, and noodle and for

fermentation to make beer, other alcoholic beverage.

Wheat Composition

•Carbohydrate 70%

•Protein 9-15%

•Fat 2-2.2%

•Fiber 2-2.5%

•Ash 1.8 %

•Moisture 9-13%

Wheat is one of the most important foods in a balanced

diet

The nutrition community recommends that 55-60

percent of our daily calories come from carbohydrates.

Also, no more than 30 percent of our calories should

come from fat, and approximately 12-15 percent of

calories should be derived from protein.

Clearly, calories acquired from carbohydrates such as

wheat products are the healthiest and most important to

incorporate in our diets.

Complex carbohydrates provide essential nutrients, are

less likely to be stored as fat and more likely to be

stored as muscle fuel

So, what’s in wheat that makes it so healthy?

One major component in wheat which is only found in

plant foods is dietary fiber.

Dietary fiber is the carbohydrate in food which humans

cannot digest.

sweep out the digestive tract as well as satisfying a Fiber

acts as a broom to appetite longer

One slice of whole wheat bread contains 2 grams of

dietary fiber; one slice of white bread contains 0.5 grams;

and one ounce of wheat bran cereal contains between 8

and 9 grams of dietary fiber.

The American Dietetic Association recommends eating

20-35 grams of fiber each day, but on average

Insoluble fiber

Found in wheat bran and whole grains,

Insoluble fiber passes through the digestive system quickly,

promoting regularity and reducing the risk of colon

irregularities or diverticulosus, a type of colon disease.

Research suggests foods containing insoluble fiber may also

help reduce the risk of colon and breast cancer when part of

a low-fat diet.

Soluble fiber–

Found in oats, beans, some fruits and vegetables and refined

white flour products.

Studies indicate foods containing soluble fiber may help

decrease blood pressure and cholesterol levels, helping to

reduce the risk of heart disease.

They may also help control blood sugar levels in people

with diabetes.

Thiamin (B1)-

Needed daily for good appetite, digestion, and healthy nerves.

It also helps the body make better use of fat and carbohydrates.

Riboflavin (B2)-

This vitamin is essential for the use of protein by the body.

Niacin (B3)-

This is the “anti-pellagra” vitamin.

Pellagra is a nutrient deficient disease that has been virtually eliminated since the enrichment of white flour products.

Iron

Iron is essential for providing our bodies with energy.

Iron acts in this way by carrying oxygen from the lungs to

muscles and other parts of the body.

A deficiency of iron causes a disease known as anemia which

results in a lack of energy.

Protein

Wheat foods provide 2-4 grams of protein per one ounce serving.

Six to seven ounces of protein per day are required for the average teenager and adult.

Protein is an important component of every cell in the body.

Hair and nails are mostly made of protein. Our body uses protein to build and repair tissues and use protein to make enzymes, hormones, and other body chemicals.

Protein is an important building block of bones, muscles, cartilage, skin, and blood

Wheat cultivars are further classified in terms of wheat

hardness, protein content, and protein quality.

1. Hard wheat

They have high gluten content(higher protein quantity and

quality)

When hard wheat is milled the endosperm cells separate along

the cell wall margin into easily sifted particles

It has high extraction of white flour

Hard types tend to have possessing a vitreous

endosperm with starch granules tightly packed in a

protein.

During milling, some starch grains are damaged,

resulting in an increased surface area that leads to

higher water absorption

The bran is easily separated from the endosperm

It capable of high water absorption during dough

production

2. Soft wheat The gluten content is low

Soft wheat has much lower extraction rate

The flour consists of a mass of fine cell debris with poor

flow characteristics

The softer wheat have a less compact starch-protein

complex which results in less starch damage and lower

water absorption.

The protein level of soft wheat is usually lower, producing

less resistant, more extensible dough

It is required for biscuit making

3. Durum wheat It is the hardest wheat grown

Durum wheat is suitable for pasta and macaroni

It is most often ground into a granular flour with a light

yellow color known as semolina, which has the ideal

properties for making the best pasta

Durum is high in protein and gluten, which are necessary

for making good pasta

It is occasionally used for baked goods (especially risen

breads), but it is not used for this purpose as often as other

wheat varieties.

1. Physical

2. Chemical

3. Botanical

Physical

◦ Test weight (HLW)

◦ 1000 kernel weight

◦ Hardness

◦ Color

◦ Impurities

◦ milling quality

◦ virtuousness

2. Chemical

Moisture

protein content

alph-amylase

ash or color grade value

fat acidity

3. Botanical- commercially important wheat’s falls under three

species (Triticum aestitivum, Triticum compactum and

Triticum Durum)

Test weight/Hectoliter weight

Test weight, measured as weight of grain per unit

volume, is the simplest and most widely predictor for a

grain’s milling quality.

Test weight per bushel is a grading factor

Test weight is defined kg/hl

Wheat 74kg/hl =poor, 78kg/hl=good and 82kg/hl=very

good

Wet gluten

Gluten is prepared by washing out most of the starch and soluble from a piece of dough developed from flour and water.

The wet gluten can be examined visually for its color and elasticity. The required sample:-10g of flour, 20g salt, 1000ml of waterProcedure

Take 10g of flour and added to dish Add 5-6ml of 2% NaCl solution Then mix well for 8-10 minutes, and then put for 10 minute in

distilled water After 10 minutes, then wash carefully with 300-400ml of NaCl

solution. Press it to remove the water by using small presser Weight in the balance Calculate the percentage of the gluten content by multiplying with

10.

Wheat flour is the most important ingredient in home

baking

It is the framework for almost every commercially

baked product and pasta.

Of the grains available for the production of flour,

wheat is unique

It is the only cereal grain with sufficient gluten content

to make a typical loaf of bread without being mixed

with other grains

There are three part of wheat kernel (wheat berry)

Wheat Flour cont….

The wheat kernel consists of the bran, endosperm and germ.

Bran is the hard outer covering of the wheat kernel

◦ Botanically known as coat of many layers, precarp, seed coat,

hyaline, aleurone layer.

◦ It is high in fiber and nutrients

Endosperm constitutes more than 80% by weight the inside of

the kernel-mostly starch

Germ is the nutrient rich embryo that will sprout and grow into a

new wheat plant.

◦ major distinctive part of the germ are embryonic axis and

scutellum

Wheat berry Part %

Bran Preicarp and testa 6.4

Aleurone layer 6.7

Endosperm Starchy endosperm 84.1

Germ embryonic axis 1.3

scutellum 1.5

Total 100

Bran All purpose flour

1. All-purpose flour

is a product of the ground endosperm of hard wheat or a

combination of hard and soft wheat kernels.

It can be used for

any recipe requiring flour such as breads, cakes, and pastries;

as a coating for meat, vegetables, and other food items

intended for frying or sautéing;

and as a thickening agent for gravies, sauces, and stews.

All-purpose flour is available in bleached, unbleached

and enriched

1.1. Enriched all-purpose flour has iron and B-

vitamins (thiamine, niacin, and riboflavin) added in

amounts equal to or exceeding that in whole wheat

flour.

1.2. Unbleached all-purpose flour

Unbleached all-purpose flour is bleached by oxygen

in the air during an aging process and is off-white in

color.

Nutritionally, bleached and unbleached flour are

equivalent.

1.3. Bleached all-purpose flour

It is exposed to chlorine gas or benzoyl peroxide to

whiten and brighten flour color.

Chlorine also affects baking quality by “maturing” or

oxidizing the flour, which is beneficial for cake and

cookie baking.

The bleaching agents react and do not leave harmful

residues or destroy nutrients.

2. Bread flour

It is ground form the endosperm of the hard red spring wheat kernel.

Bread flour is similar to all purpose flour, but it has greater gluten strength and is generally used for yeast breads.

The high gluten content is necessary in order for bread to rise effectively.

The use of bread flour results in larger bread loaves with a lighter and less crumbly texture.

Bread flour is unbleached, high-gluten flour that typically contains 99.9 % hard wheat flour with malted barley added to increase the yeast activity, making it ideal for bread making.

Bread flour is also referred to as unbleached flour.

3. Cake flour

Cake flour is produced from the endosperm portion of

the wheat kernel of soft wheat varieties.

It is high in starch and has a low protein content, which

means that it contains very little gluten, making it

suitable for cake recipes.

It is especially suitable for cakes, cookies, crackers, and

pastries.

If cake flour is not available, cornstarch makes a good

substitute.

4. Pastry flour

Pastry flour is produced from soft-wheat and it has a fine-texture and a high starch content, but less starch than cake flour.

It is milled from a soft, low gluten wheat and is used for pastries.

Pastry flour is finely ground, but it is not as fine as cake flour.

It is available in bleached and unbleached varieties and is most often used for making flaky pie crusts, cookies, biscuits, and assorted pastries.

5. Semolina Flour

Semolina flour is available coarsely ground or ground

twice for a fine texture with a light yellow color

It is the coarsely ground endosperm of durum wheat

which is used almost exclusively for making pasta.

Durum wheat has the ideal properties for making the

best pasta.

It is high in protein and gluten, which are used to create

high quality pasta products such as macaroni and

spaghetti

6.Whole-Wheat Flour

Whole-wheat flour is produced from grinding the full wheat berry (kernel).

All parts of the wheat berry are used in the flour including the bran, germ, and the endosperm, which when milled, creates the speckled brown color that is characteristic of the flour

Three granulations (particle size) of whole-wheat are produced: fine, medium, and coarse.

The particle size influences the rate liquid is absorbed into the flour.

Finer grained flour absorbs liquid at a faster rate than medium or coarse grains, thus affecting the preparation of the dough.

Fine grain whole-wheat flour is used for all types of baked goods, such as breads, rolls, and pastries.

Medium grained can be used for the same types of foods, but will provide a coarser crumb.

Coarse whole-wheat flour has a much larger bran particle and consequently is most often used to provide breads with natural, nutty flavors and rough textures.

WHITE FLOUR is made from endosperm only= not whole grain

WHOLE WHEAT FLOUR combines all 3 parts of the wheat kernel=whole grain

Quality parameters of the flour such as color, protein, granulation distribution, gluten quantity and quality, and starch damage play a role in the suitability of flour for the baker.

Physical test:- Color, milling quality and Virtuousness.

Chemical test:-Moisture, protein, fiber, starch, mineral content and color grade

Amounts and types of final products vary among mills are a result of differences in flow-sheet, adjustments, and

kinds of wheat milled

Flours from the different stages in the mill are not identical in physical appearance, chemical analysis, or baking

properties.

Another important factor besides the determination of quality is the concept of flour uniformity

Optimum flour granulation distribution is an important parameter for the baking process.

Drastic change in granulation effects on water absorption, water retention during

fermentation, proofing, and

quality of finished breads.

Flour color depends on wheat cleanliness,

tempering level,

fineness of flour, and

the amount of bran particles it contains.

Too much fine bran effects flour shade, producing a darker shade.

Change in mill ambient conditions could also affect flour color.

Mixing of different quality wheat varieties so as to meet desired product quality.

Blending is mostly done on protein basis.

Hard wheat varieties are blended with soft wheat varieties in order to obtain the desired level of protein content in the resulting flour.

Traditional wheat product used in Ethiopia

Wheat Nifro and Qolo Wheat Injera Difo Dabo Chechebsa Dabo qolo Kitta

Wheat products In world Bread Biscuits Cookies Pastry Cakes Macaroni Pasta Noodle Beer and alcoholic

beverage

1. BREAD It is yeast leavened wheat product Bread is made by many different procedures. The particular procedures used depend on

tradition, the amount (cost) and type of energy

available the type and consistency of the flour

available, the type of bread desired, and the time between baking and eatingWhat are the major recipes?

The major ingredients for bread making are wheat flour, yeast, water and salt

The other ingredients are fat, sugar, milk or milk solids, oxidants, enzymes, surfactants, and additives to protect against molds.

Flour is responsible for the structure of the bread and it allows the formation of visco-elastic that retains gas.

Yeast is the major role to convert fermentable carbohydrates into Co2 and ethanol.

The gases provide the lift that produces a light or leavened loaf of bread.

The Salt functions in bread making are taste and affect rheological properties.

It makes dough stronger by shielding charges on the dough protein.

The last fundamental ingredient is water which is a

plasticizer and solvent. Shortening/oil-bread stays soft and more palatable for a

long period of time.

giving increased volume to bread

acts as a plasticizer in dough

Sugar- It is source of fermentable carbohydrates for the yeast

It provides a sweet taste to the bread

Oxidants- ascorbic acid, potassium bromate, and calcium peroxide at level PPM

improve dough strength and results in bread with better loaf volume and texture.

The processing of bread can be divided into three basic operations:

mixing or dough formation,

fermentation, and

baking

Two procedures1. Straight-dough system

2. Sponge-and dough process

Type of breada. Pan bread

b. Baguettes and Hearth breads

c. Flat breads

d. Buns

e. Croissants

Bread ingredients

The basic dough formula for 500 g flour consisted of salt (7.5 g), yeast (5 g), baking powder (4 g) and water, which needed to have a consistency

Procedures for bread making

Mix 500g of the flour with small amount of water little by little

Then add and mix 5gm of yeast, 7.5gm of sugar, 5gm of salt (Common salt) and 0.5gm improvers to the flour.

If the dough creates a smooth surface then it’s enough for water observation and extruding.

After mixing, the dough will be placed in the fermentation cabinet at a temperature of 30°C and 85% RH for 45 min.

Then again set for 2nd development for 20 minutes

After fermenting the dough divided and molded using a dough-forming device and put into pans for the final proofing.

The dough samples will ferment until they reach 2 cm above the rim and then baked.

The baking oven temperature reaches to 230-260°c for 20-22 minutes

Cool the bread loaves at room temperature for 5min

Test the color of the bread(crumb, sponge)

Test the weight

Test volume(texture)

Test water absorption

Flow sheet for the straight dough procedure of bread processingAll formula ingredients

Mix to optimum development

Ferment for 100 min

Punch (Mixing 2or more)

Ferment for 55 min

DivideIntermediate proofing for 25 min

Mold and pan

Proofing for 55 min

Baking

The main ingredients for biscuits and cookies production are

wheat flour, fat (shortening), sweeteners (sugar), Leavening agents (baking powder), eggs, milk, salt and flavors.

Wheat flour Wheat gluten generally determines the suitability of

flour for biscuit making.

The softer wheat have a less compact starch-protein complex which results in less starch damage and lower water absorption.

The protein level of soft wheat is usually lower, producing less resistant, more extensible dough.

Soft wheat is a unique blend of white, soft grained wheat varieties.

Less starch damage from soft wheat flour thus occurs which favors an increase in biscuit diameter.

Flour protein levels needed for biscuit making typically range from 7 to10% and are often selected by functionality for end use , price, and availability

The flour protein has a major influence on biscuit quality and in particular, on its diameter.

The quantity and quality of the protein present in flour have a major role in influencing the rheological behavior, particularly when flour is the major constituent of the formula.

Sweeteners (sugar) All biscuit formula contains sweeteners, which contain

the bulk of dissolved material in most dough. It contributes to texture, flavor, sweetness and color in

biscuit The quantity, granulation and type of sugar used

influence the quality of biscuits Sucrose, a non-reducing disaccharide, is the common

sugar used in biscuit preparation The continuing change in texture and development of

the final crispness has been attributed to slow crystallization of sucrose from concentrated sugar syrup formed during the earlier stage of processing

Up on cooling, much of it crystallizes and strongly affects the texture of baked biscuits.

Sugars functionality in biscuits systems includes more than only imparting sweetness

Shortening (Fat)

Fat are used as surface sprays in cream filling and coating and as

release agents

Fat functionality is very versatile in baked products that include

providing of flavor and mouth feel and contributes to the

appearance, palatability and texture of the biscuits

Fat is the principal recipe responsible for tenderness, keeping

quality, grain and texture and it adding a rich quality to biscuit.

Mechanical properties of biscuit are largely dependent on the fat

components of the formulation

Water

Water is often a processing aid or catalyst, rather than as an

ingredients.

Water functions in several ways, including

hydrating flour protein and starch,

dissolving sugars, salt and various leavening chemicals

aiding in ingredient distribution and

helping control dough temperature

A dough consistency is directly related to its water content or

absorption.

Water activity is an important way to measure and monitor water

mobility in baked products.

Baking powder (Leavening Agent)

Leavening agent aerates the dough to make light and porous

It is responsible for good volume, improved eating quality and

uniform cell structure.

Mostly used leaving agents are sodium bicarbonate and sodium

Meta bisulfate

Other Ingredients

Other ingredients include milk, egg, salt, honey and aerating

agents.

Milk and eggs are a good source of protein and lactose, which aid

in shape retention and browning reaction.

Salt perform two principal functions in biscuit dough. The first is

flavor and controls fermentation and aids in suppressing

undesirable bacteria as a second function of salt

Biscuit dough generally falls into two broad categories- hard and soft

dough.

The visco-elastic properties of hard dough represent the presence of a

protein (gluten) matrix which is developed during mixing and

sheeting.

During baking, the biscuit may continue to shrink in outline, but

become thicker.

Soft dough does not have formed gluten structure, because of their

high levels of shortening and sugar, and are generally mealy or sandy

in texture.

Dough pieces formed from soft dough tend to retain their shape until

baking, but then they spread or flow, becoming thinner.

Dough undergoes several changes during baking:

Changes in dimension and texture,

loss of moisture, and

color and flavor development are the most important.

Baking is divided into three phases.

The first involves dough expansion and the start of moisture loss.

Dough expansion and water loss reach maximum rates and color

development start during second phase.

The third phase concludes baking with a lower rate moisture loss,

thinning of the biscuit, and increasing surface area

Biscuit ingredients Biscuit dough will be prepared using a mixture of

wheat flour 100g, sugar powder 30 g, shortening 20 g; skimmed milk powder 2 g; sodium chloride 1 g; ammonium bicarbonate 1 g and sodium bicarbonate 0.5 g.

Biscuit preparation 1. Sugar, fat and skimmed milk powder will be

creamed in the mixer for 2 min at 121 rpm and 5 min at 173 rpm, respectively.

2. Add water containing sodium chloride, ammonium bicarbonate and sodium bicarbonate to the above cream and mix for 5–6 min at 121 rpm to obtain a homogenous cream.

3. Finally wheat flour will be added and mixed for 3 min at 60 rpm.

4. Dough will be sheeted/molded using a rolling pin to a thickness of 3.5mm with the help of an aluminum platform and frame

5. Biscuits will be shaped with a cutter of 55mm diameter and baked on an aluminum tray at 200 °C for 9–10 min when a very light brown color form before removal of the biscuit

6. It allows cooling and storing at atmospheric temperature.

Cookies makingCookies ingredients

Cookies with straight grade wheat flour (500 g), sugar (250 g), hydrogenated vegetable ghee (250 g), eggs (60 g each) and baking powder (10 g).

Preparation of cookies1. Weigh the ingredients accurately

2. Mix vegetable ghee (oil) and sugar, then add eggs one by one.

3. The straight grade flour are homogenously mixed and blended with baking powder and sifted.

4. Add the flour to sugar ghee- egg mass and mix to get a homogeneous mass.

5. Roll the batter with uniform thickness with the help of the rolling pin

6. Cookies will be cut out with the help of cookie cutter and placed in trays.

7. Baking will be done at 170–180 °C for 15–20 min.

8. Cookies will be allowed to cool at room temperature for 8–10 min and stored in airtight glass jars

Flow chart for the preparation of Biscuit and cookies

Wheat flour, Water and baking ingredient

Weighing

Mixing

Kneading

Shaping

Baking (175 0C for 20 min)

Cooling

Storage

Pasta

Pasta products are produced/made are semolina (wheat flour), water and other optional ingredients.

The wheat flour (semolina) which consists of fine particles of uniform size and produces the highest quality of pasta products.

Macaroni

The raw material of macaroni products produced from wheat flour, water and other optional ingredients.

The wheat flour used for macaroni is both hard and durum wheat which consists of fine particles of uniform size and produces the highest quality

The process flow chart of pasta products

Mixing of the ingredients (wheat flour and water)

Pre mixer, Mixer and Vacuum mixer

Dough preparation

Screw conveyer

Extrusion

Cutting

Dryingpre dryer, 1st ,2nd &3rd dryer

Cooling

Packaging

The process flow chart of Macaroni

Mixing of the ingredients (wheat flour, water …)PremixerMixer

Dough preparation

Molding

CuttingDrying (pre dryer, dryer)

Stabilizer

Packaging

Raw material quality of pasta and macaroni The flour granulation level should be checked. If the sieve size is 129µ, the granulation of the flour

must between 35-45% as well as If the sieve size 180µ, the granulation of the flour

must between 60-70%

Final quality determination of pasta and macaroni The quality evaluation of pasta and macaroni

products involves color, appearance, texture and cooking quality

a. Appearance, texture and cooking quality color are evaluated by organoleptic test/sensory

b. Color (brightness, purity) can be assessed by sensory

c. Determination of cooking test

Evaluation of cooking test parameter Cooking tester apparatus are stove, balance, dish and beaker Procedures If possible to check the moisture content of the sampled products Pour 1L of water in the dish and wait till if boil and then add the

sample(100g) .If the sample is long cut pasta to minimized into small pieces Stir using wooden rod and test the cooking sense If the cooking is ok, then distilled water (residue) and rinse with

water Check the aromatic sense check the water observation Check any other defectCalculationWater Observation =Final weight-Install weight/

Install weight Final weight= Weight of the cooked product Install weight= Weight of the product before cooked

Quality defects

The common quality defects of pasta and macaroni

white spot

Crack

Bend for pasta

The color of final product pasta and macaroni are yellow color

There are two classes of deep fried pastries,

1. yeast raised doughnut and

2. cake doughnut.

Both products have rather specific flour requirement that vary somewhat according to end product and process requirements.

In both cases flour blend high protein hard wheat flour and low protein soft wheat flour are required.

Yeast raised doughnut:-

are made from dough containing yeast as leavening agent

This dough is similar to bread dough The ingredients it contain

require a blend (60-100%) hard wheat flour and (0-40%) soft wheat flour usually with 11-12.5% protein and 8.5-9.5% protein respectively.

5-10% sugar5-10% shortening2-3 times yeast level higher than those of

bread The basic mixing or dough development

requirements are similar to bread.

Most Yeast raised doughnut are made with straight dough procedure

all ingredients are added at once

fermentation takes place with all the ingredients in the dough

Higher yeast level, less fermentation requirement than bread.

Regardless of the fermentation process, the dough is subsequently shaped as required and

It allowed to proof or rise for 25-40 minuteThe proofing condition are much drier than those required for

bread;

Proof moisture is 40-70% for doughnut as against 85-95% for bread.

then the dough pieces are fried in a deep fat fryer at about 185-195°c depending on product variety and process limitations:

they are either surface fried with turning point or

fried submerged

4. Cake doughnut (bonbolino)

are similar to cakes in that they are rich, sweet batters

produced with chemical leavening.

However, their formulas are rather different from baked

cakes due to deep fat frying of the batter.

This batter is extruded directly into the frying fat.

It is expanded during frying by the interaction of sodium

bicarbonate and leavening acids (so-called baking powder)

the raw material usedBlend of 70/30 or 50/50 soft wheat flour and hard wheat flour

Generally, a soft wheat flour of 8.5-9.5% protein and a

hard wheat flour of 10.5-12% protein appropriate for

cake doughnuts.

Flour is the predominant ingredient of the formula;

◦ flour quality is important for controlling viscosity and batter

flow

◦ and thus for the quality of the end product

The final properties of the doughnut are influenced by several factors

1. Frying fat is absorbed from the fryer during cooking. 20-24% of the final doughnut is fat, which is absorbed during

frying.

2. Control of the time at which the batter surfaces is also important

3. Control of batter flow during frying is critical4. The batter must have adequate strength just before the

doughnut is turned to prevent excess bubbling or gassiness at the batter surface. this prevents excess fat absorption and small holes in the

surface of the doughnut flour quality helps to support the batter strength