Wet milling products

Table II. Yields and processing efficiency of dry and wet milled products from field pea and fababean, dry basis.

Proper operation of a wet-milling system requires the use of 1420-1830 L of fresh water per metric ton of corn (15-22 gal per 1001b), all added at the final hydroclone stage. This water must eventually be removed from the products by evaporation, since most wet-milled products are marketed at 10-12% moisture content. 

Yahl, K.R., Watson, S.A., Smith, R.J., and Barabolok, R. (1971). Laboratory wet-milling of corn containing high levels of aflatoxin and a survey of commercial wet-milling products. Cereal Chem., 48 385-391. 

Laboratory Milling Procedures and Quality Control Parameters Commonly Used to Determine Yields and Qualities of Dry- and Wet-Milled Products... 

The breakfast cereal industry relies on the quality control parameters previously discussed for whole grains, dry- and wet-milled products, and wheat quality tests. 

A higher density sol—gel abrasive, produced by the introduction of seed crystaUites formed by wet-milling with high alumina media or by introduction of submicrometer a-alumina particles, was patented (28) and designated Norton SG. The microstmcture of this abrasive consists of submicrometer a-alumina crystals (Fig. 1) and its bulk density approaches that of fused alumina. Norton SG has proven to be an exceptional performer in coated and bonded abrasive products it was awarded the 1989 ASM Engineering Materials Achievement Award (29). 

Some of the information available on designs of com wet-milling plants in which com oil and other products are produced indicate that integration with an alcohol plant may be more efficient than a conventional com alcohol plant. 

Gasohol in the United States. Over 90% of the fuel ethanol in the United States is produced from com. Typically, 0.035 m (1 bushel) of com yields 9.5 L (2.5 gal) of ethanol. Ethanol is produced by either dry or wet milling (87). Selection of the process depends on market demand for the by-products of the two processes. More than two-thirds of the ethanol in the United States is produced by wet milling. Depending on the process used, the full cost of ethanol after by-product credits has been estimated to be between 0.25—0.53/L ( 1—2/gal) for new plants (88). Eeedstock costs are a significant factor in the production of fuel ethanol. A change in com price of 0.29/m ( 1.00/bushel) affects the costs of ethanol by 0.08/L ( 0.30/gal). 

Hot Hthopone leaving the calciner has to be cooled quickly to prevent the oxidation of ZnS to ZnO. Rapid cooling is accompHshed by its suspension in water that might contain a small amount of sulfuric acid to remove any traces of undesirable 2inc oxide. The suspension is then wet milled, filtered off, and dried to the commercial product. 

During com wet-milling, a 40—50% soHds-starch suspension is treated with a metal hydroxide and ethylene oxide at approximately 50°C to produce DS of 0.1 and the product is purified by filtration and washing. 

In recent years, several wet milling operations have been initiated with obvious advantages in dust control and potential advantages in the separation of mineral contaminants from the fiber product. On the other hand, large-scale industrial wet classification methods are not in use at present. 

Molasses, corn steep liquor, waste product from sugar industry, and wet milling com are used for the production of penicillin... 

Imported maize is the raw material for several food ingredients used in the bakery industry. While maize can be dry milled like wheat, it is more commonly wet milled. The wet milling process is much better suited to separating the different components of maize so that the oil, the protein and the starch can be recovered separately. Maize starch is used directly in bakery products as corn flour, so-called even in the UK. 

In 2002, approximately 2.2 billion bushels of corn were processed in the United States for the production of food, fuel, and industrial products. Of that 2.2 billion bushels, 19.22 million tonnes (757 million bushels) were used for high fructose corn syrup (HFCS), glucose and dextrose, 6.34 million tonnes (250 million bushels) for pearl starch, 26.69 million tonnes (1051 million bushels) for fuel and beverage alcohol, and 4.75 million tonnes (187 million bushels) for cereals and other products (Corn Refiners Association, 2003). More than 50% of the com processed in the United States is done so using the corn wet milling process. 

Zehr, B.E., Eckhoff, S.R., Nyqyist, W.E., and Keeling, P.L. 1996. Heritability of product fractions from wet milling and related properties of maize grain. Crop Sci. 36, 1159-1165. 

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