Cereal Grains, Legumes & Oilseeds
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Transcript of Cereal Grains, Legumes & Oilseeds
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.