Cereal Grains, Legumes & Oilseeds

Ag Processing

Cereal Grains Many types Markets have expanded their range of uses

General Structure and Composition Outer bran coat

5% of the kernel Cellulose Minerals and some vitamins

Aleurone layer 8% of the kernel Lies just under the bran coat Rich in protiens, phosphorus and thiamine

Endosperm 82% of the kernel Large, central portion of the kernal Contains the most starch Also contains most of the protien but has very little mineral or fiber

Germ Small Rich in fat, protein, minerals also contains most of the riboflavin

Cereals Processed grains that are generally 75-80%

carbohydrates Fiber is also an important attribute

Bran cereals may contain 10-26 grams of fiber per cup

Contain both soluable and insoluable fiber Insoluable fiber is good for the digestive tract and

helps reduce the risk of certain cancers Soluable fiber- lowers blood cholesterol, originates

in the endosperm and is found in oats, legumes, fruits and vegetables

Starch

Starch Storage form of carbohydrate deposited as

granules or aggregate of granules in the cells of plants

Size and shape of the granules differ from various sources

Parts of the plant that serve most prominently in the storage of starch are: Seeds—cereals and legumes Roots and tubers—parasnips, potatoes, sweet

potatoes Cassava root—Tapioca Pith of the Tropical palm--Sago

Starch Make-up Granules are made up of many starch

molecules arranged in an organized matter Two types

Amylose Amylopectin

Amylose Polysaccharide of glucose Contributes gelling characteristics to cooked

and cooled starch mixtures

Amylopectin Highly branched polysaccharide of glucose Provides thickening properties but does not

usually contribute to gel formation Most starches are a mixture of the two

Milling of Grains

History of Milling Stones, wood were used by primitive people Led to water driven mills with large mill stones Modern milling replaced the mill stone with

rollers

Flour Milling Bran covering, germ and endosperm are

seperated to a desired extent Endosperm is pulverized Middlings (inner portion of the kernel) is fed

through a series of smooth rollers after being seperated from the bran to further reduce the size of the particles and produce a finer flour

6-8 streams of flour are produced from the rolling and sifting of the purified middlings, this results in various grades and types of flours. They vary in bran, germ and gluten content

White Flour Final production step is often bleaching and/or

maturing Freshly milled unbleached flour is yellowish in

color when used for baking produces a fairly course textured loaf

If the flour is stored for several months the color lighten and the baking qualities improve

FDA approves the use of nitrogen trichloride and nitrogen tetroxide, chlorine dioxide, benzyl peroxide, acetone peroxides, & azodicarbonate to bleach and mature flour

The flour then must be bleached

Flour Composition Depends On Class of wheat used Conditions under which the wheat is grown Degree of fractionation

Classes of Wheat Hard, Soft, Durum Durum is used almost exclusively for

producing semolina-granular flour of high gluten content and is in the manufacturing of macaroni products

Durum

Hard Red Spring

Hard Red Winter

Geographical Production Areas Hard Spring Wheats

North Central US, Western Canada Hard Winter Wheats

South Central and Middle Central States Soft Winter Wheats

East of the Mississippi River and Pacific Northwest Climatic and soil conditions affect the

composition of wheat, wide varations may occur within the classes

http://www.smallgrains.org/WHFACTS/growreg.htm

Grades of Flour Based on the four streams used to make them Straight grade should contain all of the four streams

resulting from the milling process However 2-3% of the poorest streams is withheld and

very little flour on the market is straight grade Patent flours come from the more refined portions of

the endosperm & may be made from any class of wheat and are divided as followed in order of quality First Patent Second Patent First Clear Second Clear Red Dog

Types of White Flour Bread Flour

Slightly higher percentage of gluten and a much stronger and more elastic gluten than other types of flour

Made chiefly from hard wheat All-Purpose Flour

Less strong and elastic gluten than bread flour May be a blend of hard and soft wheat or entirely hard or soft winter

wheats Pastry Flour

Made from soft winter wheat Contains a weaker quality of gluten and a slightly lower percentage of

gluten than bread and all purpose flours Cake Flour

Specially prepared to reduce the gluten content about 7% Best made from soft wheat Finely ground Highly bleached with chlorine

Enriched Flour White flour to which specified B vitamins and

iron have been added Calcium and vitamin D may also be added Enrichment of bakers white bread and rolls

was made compulsory by the federal government in 1941 as a war measure to improve the nutritional status of people

After the war, enrichment became voluntary

Gluten 85% of the protiens of white flour are

insoluable Separate into two fractions

Gliadin—syrupy substance that may bind the mass together

Gutenin—exhibits toughness and ruberiness that contribute to strength

Together they form gluten

Other Flours Cornmeal

Used to make quick breads Corn flour

Used to make commercial pancake mixes Barley flour

Used for making extruded cereals, cakes, cake donuts, cookies and crackers

Oat flour Not common Cakes, cookies, crackers

Rice flour Used in many products as a substitute for those who have an

allergy to wheat Cannot be used in products that require gluten Basically rice starch

Corn Refining

Corn Refining Leading example of value added agriculture 1.2 million bushels of corn are used to

produce for the world market Food Industrial and feed products

Refiners separate shell corn into its components Starch Oil Protein Fiber

Convert them into higher value products

Inspection and Cleaning Upon arrival the corn is inspected and cleaned

twice to remove cob, dust, chaff and foreign materials

Corn Refining See handout

Steeping Corn is soaked for 30-40 hours in 50 degree F

water Moisture level of the corn is increased from 15

to 45% More than doubles in size Mild acidity of the steep water begins to

loosen the gluten bonds and release starch Corn is coursely ground after steeping to

break the germ loose Steepwater is condensed to capture nutrients

for use in animal feed and for use in later fermentation processes

Ground corn in a water slurry goes to the germ seperators

Germ Separation Cyclone separators spin the corn germ out of

the slurry Germs are pumped onto screens and washed

repeatedly to remove starch Mechanical and solvent processes are used to

extract the oil from the germ 85% of the oil in the corn is found in the germ

Oil is then refined and filtered into finished corn oil

Germ residue is saved as another component of animal feed

Fine Grinding and Screening Corn and water slurry are ground a second time in

an impact or attrition impact mill after leaving the germ seperator

This releases the starch and gluten Suspension of starch, gluten and fiber flows over

concave screens that catch fiber but allow starch and gluten to pass through

Fiber is collected, slurried and screened a second time to reclaim residual starch or protien then sent to the feed house where it is used as a major ingredient in animal feeds

Starch-gluten suspension called mill starch is piped to the starch seperators

Starch Separation Mill starch is passed through a centrifuge

where the gluten is spun out for use in animal feeds

Starch is diluted, washed 8-14 times, rediluted and washed again to remove protiens to produce high quality starch that is more than 99.5% pure

Starch is dried and marketed in one of the following forms Unmodified corn starch Modified speciality starch Corn syrup and dextrose (most)

Syrup Conversion Starch suspended in water is liquified in the presence of acid

and/or enzymes that convert the starch to a low dextrose solution

Treatment with another enzyme continues the conversion process

Throughout the process refiners can halt acid or enzyme actions at key points to produce the right mix of sugars like dextrose and maltose for syrups that meet different needs

For example: To produce low to medium sweetness syrups starch to sugar

conversion is halted at an early stage In others the conversion is allowed to continue until the syrup is

nearly all dextrose. The syrup is then refined in filters, centrifuges and ion-exchange columns and excess water is evaporated.

Syrups are then sold directly, crystallized into pure dextrose or further processed to create high fructose corn syrup

Fermentation Dextrose is one of the most fermentable

sugars Following the conversion of starch to dextrose

many corn refiners pipe dextrose to fermentation facilities where the dextrose is turned into alcohol

After fermentation the resulting broth is distilled to recover alcohol or concentrated through membrane separation to produce other bio-products.

Carbon dioxide from fermentation is recaptured for sale and nutrients remaining after fermentation are used as componenets of animal feed ingredients.

Bioproducts Ethanol Organic acids Amino acids-used in animal nutrition Vitamins Food gums Citric and lactic acids Plastics Eco-foam packing peanuts

Legumes

Legumes Provide protien and energy to much of the

world’s population Found almost everywhere in the world

Common Legumes Alfalfa Beans

Kidney, Navy, Pinto, Snap Cowpea Chickpea Field pea Garden Pea Lentil Lima Bean Peanut Soybean

Nutritional Composition Good sources of Carbohydrates Fats Proteins Minerals Vitamins Mixtures of legumes and grains have a protein

quality that comes close to that of animal protein

Legume Products Fermented Foods

Soysauce, tempeh, tofu Flours

Soybean flour (used to make soy milk and low-gluten baked foods)

Imitation meat Infant formulas Oil

Soybean and peanut Sprouts

Assignment Design a poster showing all the products that

can be made from soybeans. Show pictures of these products and give a description of them.