🥣 Cereals, Tubers, and Co-Products

Cereals, Tubers, and Co-Products

Cereal Grains

8 Major Cereal Grains
  • B → Barley (Hordeum vulgare)
  • C → Corn (Zea mays)
  • O → Oats (Avena sativa)
  • W → Wheat (Triticum aestivum)
  • M → Millet (Panicum miliaceum)
  • R → Rice (Oriza sativa)
  • R → Rye (Secale cereale)
  • S → Sorghum (Sorghum bicolor)

Global Cereal Grain Production – 2020

Annual Production
  • Measured in million metric tonnes (MMT)

Corn
  • 1,173 MMT

Wheat
  • 784 MMT

Rice
  • 508 MMT

Barley
  • 147 MMT

Sorghum
  • 60 MMT

Corn production, 1961 to 2020

U.S. Corn Utilization

Fuel Ethanol and Sustainable Aviation Fuel (SAF)

Renewable Fuels
  • Governments around the world have mandated the use of renewable fuels → fuels made from renewable sources
  • Examples → ethanol in transportation and SAF (Sustainable Aviation Fuel)
  • Governments may provide incentives or pass legislation requiring a certain level of renewable fuels to be used by different industries

Production
  • These policies are driving production of ethanol from grains
  • Biodiesel → produced from vegetable oil or animal fats

Why Use Food Resources for Fuel?

Why Use Grains for Fuel?
  • Precious food resources such as grains are used to produce fuels → ethanol, biodiesel, SAF, etc.
  • Driven by arguably important policies → e.g. climate change mitigation efforts
  • Driven by economics → there is demand and buyers for these products, creating opportunities for farmers to make a profit

Co-Products and Animal Feed
  • Fuel production creates co-products that can be valuable animal feed resources
  • Examples → DDGS, oilseed meals
  • Increased demand for renewable fuels can increase global food production because of these co-products
  • Higher production of corn, soybean meal, canola, etc. → higher production of co-products → more feed ingredients available to the animal feed industry

Economics and Food Supply
  • Agriculture, food production, and animal production are driven by economics
  • Issues of food supply, accessibility, affordability, and security in many regions can be caused by logistical and political problems
  • It is never as simple as that → many factors influence food and feed production

Corn Production in Ontario

Corn Production
  • Corn is widely grown across southern Ontario

Grain Corn – 2004–2015
  • Average acreage → 769,000 ha (1.9 million acres)
  • Average yield → 9.53 t/ha (152 bu/acre)

Corn Silage
  • Additional 118,000 ha (0.3 million acres) grown as corn silage for livestock feed

Uses of Grain Corn
  • 55% → used for feed
  • 45% → used for industrial purposes

Grain Milling By-Products – Dry Milling

Dry Milling
  • Large volumes of cereal grains such as wheat, rice, and corn are dry milled
  • Used to produce a variety of food and industrial products

Wheat
  • Dry milled to produce wheat flour for human consumption
  • Process generates by-products used widely in animal feeds
  • Wheat bran
  • Wheat middlings
  • Wheat shorts

Rice
  • Dry milled to remove the husk and bran → produces white rice
  • Process produces several by-products
    • Rice bran
    • Deoiled rice bran (DORB)
    • Rice polishings
    • Broken rice
    • Rice bran oil
  • These products are commonly used as animal feed ingredients in major rice-producing countries

Wheat Milling Co-Products

Co-Products
  • Variety of co-products with different levels of starch, protein, and fiber
  • Bran
  • Middlings
  • Shorts
  • Mill run
  • Red dog flour

Grain Milling By-Products – Wet Milling

Wet Milling
  • Corn and other grains can be wet milled to extract different components
  • Corn is soaked in warm water for 48–60 hours
  • Grain is then ground into a slurry → mixture of grain and liquid
  • Slurry is screened to remove corn bran
  • Then centrifuged → separates the starch

Corn Gluten Meal
  • Remaining protein-rich fraction → corn gluten meal
  • If wheat is wet milled → wheat gluten meal

Steep Water
  • Steep water → water in which corn grains were soaked
  • Contains part of the soluble nutrients of corn
  • Also contains fermentation products → e.g. lactic acid
  • Can be partly dehydrated → produces corn steep liquor

Ethanol Production
  • Corn grains can be fermented with yeast to produce ethanol (EtOH)
  • Ethanol → used as a fuel source
  • Components of the grain remaining after fermentation + yeast biomass are recovered and dried
  • Produces dry distiller’s grains and solubles (DDGS)
  • DDGS is widely used in swine, poultry, and ruminant feeds

Corn Wet Milling Process

Initial Processing
  • Corn cleaners → clean the corn
  • Steep tanks → corn is soaked
  • Steep water → water from soaking
  • Steep water evaporators → concentrate the steep water

Germ Separation
  • Germ separators → separate the germ from the corn
  • Germ extractors → extract components from the germ
  • Germ → used to produce oil and germ meal

Grinding and Separation
  • Grind mills → grind the corn
  • Washing screens → separate hull
  • Centrifugal separators → separate components based on density
  • Gluten → protein-rich fraction
  • Starch washing hydro-cyclones → wash and separate starch

Products and Co-Products
  • Gluten meal
  • Gluten feed
  • Germ meal
  • Condensed fermented corn extractives
  • Oil
  • Starch
  • Sweeteners
  • Ethanol

Other Components
  • Pigments → 200–550 ppm

Ethanol – DDGS Production

Ethanol Production Process
  • 1. Milling → corn is milled into meal
  • 2. Liquefaction → water is added and the meal is cooked
  • 3. Starch Breakdown → starch is broken down into sugar
  • 4. Fermentation → yeast is used to ferment the sugar into ethanol
  • 5. Distillation → ethanol is separated by boiling off and condensing it
  • 6. Water Removal → residual water is removed
  • 7. Denaturing → ethanol is made undrinkable

Roots & Tubers

Cassava
  • Manihot esculenta

Potato
  • Solanum tuberosum

Yam
  • Dioscorea spp.

Sweet Potato
  • Ipomoea batatas

Cassava

Uses
  • Cassava is a tuber that can be used in human nutrition
  • Countries such as Thailand and Indonesia produce large volumes of cassava for use in animal feeds
  • Used in swine and poultry feeds

Nutritional Composition
  • Tubers are very rich in starch
  • Very low in protein

Cassava Peel
  • Peel contains cyanogenic glycosides
  • When the peel is disrupted, these compounds release cyanide