Module 8- corn processing and products Flashcards
how is most corn processed
Most corn is processed by wet milling the grain
what is wet milling
Wet milling uses water in the grinding process to effect a separation of the starch, fibre, protein and soluble components of the grains
what is wet-milled food used for
Wet milled corn products are used in a wide variety of feed, food and industrial applications.
what is the process of wet milling
The process begins with a thorough cleaning of the incoming material followed by steeping or soaking in water that contains a trace of sulphur dioxide. The corn is steeped for 1.5 to 2 days at 50°C to soften the grain and increase the moisture content to 45 to 50 percent. The sulfur dioxide inhibits bacterial growth and begins the breakdown of the protein in the starchy endosperm. The pre-soaked grain is then shredded in a degerminating mill to separate the oil-rich germ from the starchy endosperm. The germ is collected by density separation, dried and removed for oil extraction. A high quality protein meal is produced from the germ after the oil is extracted. The degermed grain is ground very fine in a wet milling system and screened to remove bran and endosperm cell wall fibre. The resulting starch-protein milk is separated into solid (starch) and liquid (protein, sugars, etc.) fractions by centrifugation. The starch is further refined by washing and drying yielding a very refined starch product. The soluble liquid fraction is a by-product that usually enters the livestock feed chain
what are the steps of corn milling
1) cleaning
2) steeping
3) degermination
4) milling
5) screening
6) centrifusion
7) cleaning
what comes out of the steeping process of wet milling
steepwater
what comes out of degermination of went milling
the germ
what comes out of the screening process of wet milling
fiber
what comes out of the centrifugation process of wet milling
protein and starch
what is dry milling of corn used for
Dry milling of corn is used to produce bran, germ, grits, meal and flour
when is corn bran and germ removed for roller milling
Corn bran and germ are removed prior to roller milling
what is the bran used for from roller milling
The bran is used for human consumption and in livestock feeds
what is the germ used for from roller milling
The germ is used for the production of corn oil and cornmeal
what are the grits, flour and starchy endosperm from roller milling used for
Grits, flour and meal from the starchy endosperm are used in the production of snack foods, tortillas, chapattis, ready-to-eat breakfast cereals, brewing and distilling and the production of grain alcohol
is roller milling corn like roller milling wheat
Roller milling corn requires some modifications relative to the process used for wheat because of the large germ and the different end-products being collected
explain the process of corn milling
Corn milling begins with a degermination step during which the moisture level is raised to approximately twenty percent and the kernels are torn open to expose the germ. Following degermination, the process is essentially the same as that used for wheat; a gradual reduction in particle size and separation of bran, germ and starchy endosperm as discrete fractions. Dry milling improves palatability, digestibility and functionality of the grains
what kind of corn is mostly milled
Most of the corn milled is dent corn
why isn’t flint corn and flour corn as easy to mill
Flint corns are much harder and, therefore, more expensive to grind. Flour corns are easily ground but lack disease and insect resistance making them more expensive and more difficult to cultivate
how much of the world’s corn grown is feed to livestock
Globally, seventy percent of corn grown is used for livestock feed
why is it not the worst thing that most of the corn goes to livestock
many of the products used for livestock feed cannot be consumed by humans
what do livestock ingredients include
Livestock feed ingredients include processed or unprocessed stalks and leaves, by-products of processing for human consumption and by-products of biofuel processing
what is the largest crop produced in the usa
corn
why is corn a good crop to be grown
Corn is a versatile, high-yielding crop and the thousands of commercial varieties make corn productive across a wide range of environments
Is corn commonly used for direct consumption? In what form is the most common
Only a small fraction of the corn produced in the United States becomes food for domestic human consumption and most of that which is used for human consumption is high-fructose corn syrup
what is involved in the corn industry
Corn production is widely criticized as production is geared towards biofuels and livestock feeds, it supports widespread monoculture farming and maximizing yield requires high water and fertilizer inputs
why is something we can do to improve corn production
While corn is a renewable resource with a myriad of uses, its sustainability requires closer examination.
