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Types of Corn

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					SCSC 306: Grain, Fiber, & Oilseed Crops




               Corn
        Types and Utilization

                        Wayne Smith
                  Professor, Cotton Breeding
                    Office: (979) 845-3450
                  Email: cwsmith@tamu.edu
SCSC 306: Corn: Basic types and their utilization



 Five Basic Types:
 • Dent (USA)
 • Flint
 • Popcorn (USA)
 • Sweet (USA)
 • Floury
 • Pod
SCSC 306: Corn: Basic types and their utilization - Specialty Types


   Specialty Types of Corn

   • Food Corn
      –   White
      –   Yellow
      –   Blue
      –   QPM
   • Waxy
   • High Amylose
     Corn
   • High Oil Corn
      – IP (identity
        preserved) issues
SCSC 306: Corn: Basic types and their utilization

     Modified Endosperm in Corn
     • Normal Endosperm
         – 75 % Amylopectin
         – 25 % Amylose
     • Waxy Endosperm
         – 100 % Amylopectin
         – Industrial Uses
     • High Amylose
         – 50 % Amylopectin
         – 50 % Amylose
         – Industrial Uses
SCSC 306: Corn: Basic types and their utilization -- HOC

     High Oil Corn
     • 3-4% higher in oil             Type              Oil
     • Higher energy feed           Normal            5-6%
       grain
     • Developed from a             High Oil          8-10%
       long term recurrent
       selection program for            Xenia: Effect of the
       high oil content.                pollinator on the grain
     • Utilize the xenia effect
       and Top Cross
       technology to produce
       high oil crop.
SCSC 306: Corn: Basic types and their utilization -- HOC
             Top Cross Technology to Produce
                      High Oil Corn
                                                                                      Produces
            Inbred 1 x                    Inbred 2                                    excessive
                                   (male fertile but not a
             (male sterile)
                                    restorer of fertility)                             pollen

                                                               High Oil
                      F1 Hybrid                      +
                           (5% oil)                            Pollinator
                         (male sterile)                      (15% oil, male fertile
                                                              and same maturity)
                         (90 %)
                                                                 (10 %)

  This mix (in green above) is sold to producers. The HOP pollinates the
  hybrid and thus the farmer harvests seed from the hybrid and the HOP
  plants. Xenia** effect increases oil content in the grain to 8-10%,
  depending on environmental conditions.
  ** Xenia: botanical meaning is the influence of pollen upon the form of the fruit
  developing after pollination.
SCSC 306: Corn: Basic types and their utilization -- HOC
            Top Cross Technology to Produce
                     High Oil Corn
   Advantages of High Oil Corn:
   The primary advantage of high oil corn is to the livestock producer,
   particularly poultry, dairy, and swine producers. Rapid rates of weight gain
   require the intake of enormous amounts of energy. High oil corn contains more
   stored energy in the form of oil than regular corn, resulting in as much as 10%
   increase in weight gain or milk production.

   Disadvantages
   Lower corn yields, increased kernel damage, and the potential for increases in
   insect damage. Lower yields due to yield potential of the hybrid AND because
   almost 10% of the planting seed in the bag are the unproductive male
   pollinator.
SCSC 306: Corn: Basic types and their utilization – Food corn

        Food Corns
    •   Food Corn –harder dent type
    •   White Cob – no staining of grain
    •   Types (White, Yellow, Blue)
    •   QPM (quality protein maize)
         – High in lysine and threonine, better
           amino acid balance
         – Important in developing countries for
           more balanced human nutrition
         – Interest in the US is in lower feed input
           costs for balanced ration
    • Zero tolerance of mycotoxins
    • Contract Growers
         – Nebraska, Iowa
         – Texas has limited production
    • Most Food Corn is Dry Milled
SCSC 306: Corn: Basic types and their utilization in USA


     Corn Utilization
     • U.S. Production
         – 56 % Feed Grain
         – 15 % Milled
            • Wet Milled (12%)
              (industrial, food)
            • Dry Milled (3%) (food)
         – 4 % Ethanol (industrial)
         – 25 % Exported (feed,
           food, industrial)
SCSC 306: Corn: Basic types and their utilization – the corn kernel
                                      A corn kernel is:
                                         – Pericarp
                                            • 8-10%
                                            • fiber and ash
                                         – Embryo
                                            • 20 %
                                            • protein and oil
                                         – Endosperm
                                            • 70%
                                            • Starch and Protein
                                      • Proximate Analysis
                                         – 73-5 % Starch
                                         – 4-5 % Oil
                                         – 9-10 % Protein
                                         – 8-10% Fiber, Ash
SCSC 306: Corn: Basic types and their utilization – feed processing

     Feed Corn Processing
     • Corn is Standard Feed           • Industrial Feed
       Grain                             Byproducts
         – Other crop feed value is
           measured relative to corn         – DDG (distillers grain)
                                               from ethanol (feed)
     • For maximum feed
       efficiency, corn must be              – Wet milling
       processed                                   • Corn gluten
         –   Cracking                              • Corn oil meal
         –   Rolling                   Ingredient             RFV to Corn (%)
         –   Grinding                  Alfalfa Hay                 30-40
                                       Animal Fat, Stabilized    210-220
         –   Steam flaking             Yellow Corn                  100
         –   Pelleting                 QPM                       100-105
                                       Barley                      85-90
                                       Grain Sorghum              95-100
                                       Oats, Whole                 80-90
                                       Wheat, HRW                100-105
SCSC 306: Corn: Basic types and their utilization -- milling

                          Grain Milling
     • Milling – purpose is to
       produce specific compounds
       for food and industrial
       applications
     • Two Types
         – Wet Milling - used to process
           grain into chemical
           components of starch protein
           and fat for use in food and
           industrial purposes
         – Dry Milling – used to separate
           the anatomical components of
           grain for use in specific food
           products
     • Most corn is wet milled.
SCSC 306: Corn: Basic types and their utilization – wet milling general


   Wet
  Milling
  Outline
SCSC 306: Corn: Basic types and their utilization – wet milling I

      Wet Milling
    • Inspection/Cleaning Grain
    • Steeping
        – Soak for 40 hours in 50 F
          water
        – Solublize Protein
        – Soften Grain (15 to 45%)
        – Coarse Grind to Separate
            • Hull
            • Embryo
            • Endosperm
        – Steepwater condensed for
          feed byproducts
        – Ground Corn to Germ
          Separators
SCSC 306: Corn: Basic types and their utilization – Wet Milling II
   • Germ Separation
        – Cyclone separate use              Wet Milling (cont’d)
          centrifugal to separate low
          density germ from slurry
        – Germ oil is extracted and
          refined to produce corn oil
        – Germ residue used as feed
          byproduct
    • Fine Grinding and
      Screening
        – Releases starch and gluten
          (protein) from fiber
        – Suspension passes through
          filters, and fiber is collected
          on filters
        – Fiber collected and used as
          feed byproduct
        – Mill starch (starch and gluten)
          to starch separators
SCSC 306: Corn: Basic types and their utilization – Wet milling III
   Wet Milling (cont’d)
 • Starch Separation
     – Centrifuged (hydroclone)
       to separate gluten
       (lighter) from starch
     – Gluten used as feed
       byproduct
     – Starch rewashed and
       hydrocloned 8-14 times
       to produce 99.5% pure
       unmodified starch
         • Used directly
         • Syrup Conversion
SCSC 306: Corn: Basic types and their utilization – Wet Milling IV


      Wet Milling (cont’d)
     • Syrup Conversion
         – Suspended starch (in H2O)
           is liquified with
           enzymes/acids
         – Modifying enzymes are
           added to convert starch to
           various forms and
           combinations of sugars
         – Reactions are stopped to
           produces syrups of different
           sugars and sweetness
         – Refined or Concentrated
             • Syrups
             • Crystals
             • Powders
SCSC 306: Corn: Basic types and their utilization – Wet Milling products

       Wet Milling - Products
   • Starches (65-70%)                    • Sweeteners (cont.)
      – Unmodified Starch: industrial        – High Fructose Corn Syrup:
      – Acid modified: industrial and          food (1984)
        food                              • Feed Products (25-30%)
      – Maltodextrins: food stabilizers      – Corn Gluten Meal (60%
        and industrial                         protein)
      – Oxidized Starches: industrial        – Corn Gluten Feed (21%
      – Pregelatinized Starch: food            protein, fiber)
      – Waxy Starch: industrial and          – Corn Germ Meal (22%
        food                                   protein)
      – High Amylose Starch:                 – Corn Steep Liquor –
        industrial (packaging) and             (condensed fermented corn
        food                                   extracts) nutrient feed blocks
   • Sweeteners                           • Oil (3-6%)
      – Corn syrups: food                    – Crude: industrial
      – Dextrose: food, industrial           – Refined: food
SCSC 306: Corn: Basic types and their utilization -- Dry milling general


   Dry
  Milling
  Outline
SCSC 306: Corn: Basic types and their utilization – Dry Milling Process

       Dry Milling - Process
   • Cleaning – removes                • Germ and Pericarp (hull) are
     contaminants                        sifted from Endosperm using
   • Tempering                           aspirators and gravity tables
      – Adjusting grain to 20-22%         – Germ extract crude oil
        moisture                          – Hulls used in hominy feed
      – Add moisture and sit for 1-3   • Endosperm passed through a
        hours
                                         series of mills and sifters to
   • Processing                          produce various sized products
      – Beall Degerminator –              –   Brewers Grits
        physically separates
                                          –   Flaking Grits
          • Pericarp
          • Germ                          –   Corn Meal
          • Endosperm                     –   Corn Flour
                                          –   PreGelled Flour Products
SCSC 306: Corn: Basic types and their utilization – Dry Milling products

       Dry Milling - Products
   • Food Products                       • Total Products
      – Flaking Grits (coarser) – Used     –   Grits, Meal and Flour (60%)
        for breakfast cereals
      – Brewers Grits (finer) –            –   Hominy Feed (35%)
        brewing alcohol                    –   Oil (2%)
      – Meals – baking, mixes, cereal      –   Lost (3%)
        foods, snack foods
      – Flour – cooking baking, snack
        foods
      – Alkali Cooked Corn (dried
        and ground to masa flour) –
        tortillas and tortilla chips
                        Ethanol from Corn
SCSC 306: Corn: Basic types and their utilization -- Ethanol

  Ethanol is a colorless, volatile, flammable liquid; an organic compound
  that has one or more hydroxyl (OH) groups attached to a carbon atom
  (CH3-CH2-OH)
  - an intoxicating agent
  - solvent
  - fuel
  - also called ethyl alcohol or grain alcohol
  - burns to a pale blue flame
      - no residue
      - considerable energy, thus an ideal fuel
  - mixes readily with water (problem!) and most organic solvents
      - ingredient perfumes, paints, lacquer, explosives, etc.
SCSC 306: Corn: Basic types and their utilization – Ethanol production
                        Ethanol from Corn
 How is ethanol produced?
 - a product of fermentation
      - a sequence of reactions which release energy from organic molecules in the absence of
            oxygen
      - energy is obtained when sugar is changed to ethanol and carbon dioxide
      - all beverage ethanol and > half of industrial ethanol is made by simple fermentation
      - steps:
           -starch in corn must be broken down into simple sugars
                 - starch + heat + alpha amylase and glucoamylase (enzymes to speed conversion)
                 - add yeast that feeds on sugar (fermentation)  ethanol plus CO2
                      C6 H12 O6  2 CH3 CH2 OH + 2 CO2
 - Commercial production
      - a more complex process; requiring a mix of technologies that include microbiology,
      chemistry and engineering. Ethanol is produced from corn by using one of two standard
      processes: wet-milling or dry-milling. Dry-milling plants cost less to build and produce higher
      yields of ethanol, but the value of co-products is less


 See Diagram of Dry and Wet Processes Next Slide
SCSC 306: Corn: Basic types and their utilization – Ethanol schematic
                        Ethanol from Corn
SCSC 306: Corn: Basic types and their utilization – Ethanol production
                        Ethanol from Corn
 What’s in a bushel (56 lbs.) of corn?
 - up to 2.5 gallons of ethanol fuel
      - only the starch from the corn is used to make ethanol
           - remaining protein and valuable co-products to be used in the production of food for
           people, livestock feed, and various chemicals
           - per bushel of corn (56 lbs.) used in ethanol manufacturing can also produce the
           following:
          The wet-milling process:            The dry-milling process:
            31.5 pounds of starch              10 one-lb. boxes of cereal
                      or                                  and                    The corn oil is used in producing food
                                         15 lbs. of brewer grits (enough for 1   for human consumption. For example,
              33 lbs. of sweetner                                                1.5 lbs of corn oil from a bushel of
                                                      gal. of beer)
                      or                                  and
                                                                                 corn is equivalent to 2 lbs of
                                                                                 margarine. The 21% protein feed is
             2.5 gal. fuel ethanol       10 eight oz. packages of Cheese Curls   used in making high protein livestock
                      and                                 and                    feed. The carbon dioxide is used as a
         12.4 lbs. of 21% protein feed           1 lb. of pancake mix            refrigerant, in carbonated beverages, to
                                                                                 help vegetable crops to grow more
                      and                                 and
                                                                                 rapidly in greenhouses, and to flush oil
          3.0 lbs. of 60% gluten meal     22 lbs. of hominy feed for livestock   wells. Only the starch of the corn
                      and                                 and                    (carbon, hydrogen, and oxygen) is
              1.5 lbs. of corn oil                0.7 lbs. of corn oil
                                                                                 used to make ethanol
                      and                                 and
           17 lbs. of carbon dioxide           17 lbs. of carbon dioxide
SCSC 306: Corn: Basic types and their utilization - Ethanol energy eq. I

                                   Corn for Ethanol
                                      Energy gain or loss?
    Data from Hosein Shapouri. USDA Office of Chief Economist
SCSC 306: Corn: Basic types and their utilization - Ethanol energy eq. II
                         Corn for Ethanol
                                      Energy gain or loss?
    Data from Hosein Shapouri. USDA Office of Chief Economist
SCSC 306: Corn: Basic types and their utilization-Ethanol energy eq. III
                                       Corn for Ethanol
                                         Energy gain or loss?
    Data from Hosein Shapouri. USDA Office of Chief Economist




   Table 3 summarizes the input energy requirements, by phase of ethanol production on a Btu per
   gallon basis (LHV) for 2001, without byproduct credits. Energy estimates are provided for both dry-
   and wet-milling as well as industry average. In each case, corn ethanol has a positive energy
   balance, even before subtracting the energy allocated to byproducts.
   Table 4 presents the final net energy balance of corn ethanol adjusted for byproducts.
   The net energy balance estimate for corn ethanol produced from wet-milling is 27,729 Btu per
   gallon, the net energy balance estimate for dry-milling is 33,196 Btu per gallon, and the weighted
   average is 30,528 Btu per gallon. The energy ratio is 1.57 and 1.77 for wet- and dry-milling,
   respectively, and the weighted average energy ratio is 1.67.
SCSC 306: Corn: Basic types and their utilization-Ethanol energy eq. IV

                           Corn for Ethanol
                            Energy gain or loss?




   Energy Gain in Making Ethanol from Corn
                      BTU's Percentage Ratio
   Industry average  30,589      38%     1.38:1
   Industry best     62,857      109%    2.09:1
   State-of-the-art  72,413     151%     2.51:1
SCSC 306: Corn: Basic types and their utilization – Grain Grading
SCSC 306: Corn: Basic types and their utilization – Grain Grading II

          U.S. Corn Classes
         • Yellow – not more than
           5% other colored corn
         • White – not more than
           2% corn of other colors
         • Mixed – corn that is
           neither yellow nor white
           class

				
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