Academic literature on the topic 'Cereal grinding'

Continenza, Romolo, and Stefano Brusaporci. "Cultural Heritages in Aterno Valley (Italy): Historical Watermills for Cereals Grinding." In History of Mechanism and Machine Science. Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4132-4_18.

"TABLE 11 Common Methods of Processing Sorghum for Use in Livestock Feed Category Type of process Procedure Characteristics Mechanical action Grinding/Rolling Particle size reduction using hammer, Most commonly used, least expensive. plate, pin, or roller mills. Increase feed efficiency and digestibility by 10-20% of whole grain. Wet process Reconstitution Increase grain moisture to 25-30%. Wet Improves feed efficiency about 10-15% grain is anaerobically stored for 2-3 over dry ground grain due to higher weeks prior to grinding and feeding. protein and energy digestibility. Early harvest Grain is harvested at 20-30% moisture Similar to reconstitution. and stored anaerobically or with organic acids (e.g., propionic). Grain is ground prior to or after storage. Soaking Soak grain in water for 12-24 h. Feed Tendency for grain to ferment or sour. whole or crush. Only limited use. Heat and moisture Steam-rolling Grain subjected to live steam (180°F) Slight increase over dry rolling. Reduces 3-5 min then rolled. fines and dust. Steam-flaking Grain exposed to high moisture steam Most common method in feedlots. Thin for 5-15 min to reach 18-20% flaking of sorghum increases moisture. Then grain is rolled to digestibility and feed efficiency equal desired flake thickness. to that of reconstitution. Pelleting Ground grain is conditioned with steam, Reduces dust, improves palatability, forced through a die, and pellets are uniformity, and handling of feeds. cooled. Prevents segregation of micronutrients. Exploding Grain exposed to high-pressure steam, Similar to puffing of cereals for breakfast the starch is gelatinized, the pressure foods. Feed efficiency is similar to is decreased, and rapid expansion of steam flaked or reconstituted grain. the kernel occurs. Hot dry heat Popping Hot, dry air expansion of grain. Bulk Ruptures endosperm increasing starch density is low. Density is increased availability. Feed efficiency is similar by spraying with water and rolling to steam flaking or reconstitution. sometimes. Micronizing Heat grain with gas-fired infrared Feed efficiency similar to steam flaking, burners to the point of eversion exploding or popping. Bulk density followed by rolling through a roller similar to steam-flaked grain. mill. From Refs. 14, 43, 44, and 86. sorghums, especially waxy endosperm types, have im-sorghum production is consumed directly by humans proved feed-processing properties [62]. [71,88]. Moist, dry, and semi-moist pet foods contain sorghum at For the production of most traditional foods, sorghum is various levels depending upon the formulation. The avail-decorticated using a wooden mortar and pestle. Hand-ability of new food-type sorghums with light color and decortication is a laborious chore generally done by house-bland flavor will lead to more use of sorghum in pet foods. wives. Sorghums with thick pericarp and hard endosperm are preferred because they are easier to decorticate [93]. In some instances, mechanical dehullers are used to service Xl. PROCESSING FOR FOOD small villages and urban areas. Milling yields are related to A. Traditional Food Systems kernel hardness, size, and shape. Most of the sorghums are milled to remove 10-30% of the original weight. The use Sorghum is processed into many different traditional foods of diesel or electrically powered abrasive mills for de-around the world (Table 12). About 30-40% of world hulling and grinding has been increasing slowly." In Handbook of Cereal Science and Technology, Revised and Expanded. CRC Press, 2000. http://dx.doi.org/10.1201/9781420027228-21.

"Length of Corrugation Land Cutting Back edge edge 1 0 --(a) (b) (c) FIGURE 8 Roll corrugations: (a) the cutting effect between rolls as a result of corrugations spiral; (b) action between corrugated rolls (S:S); (c) roll cross section showing the shape of corrugation. fast-moving roll scrapes the endosperm from the bran. As mills, it is possible to grind the material fed to the rolls in a the bran flakes get smaller toward the final breaking stages less severe manner. Roll surfaces should be maintained in and the endosperm layer attached to it becomes thinner, good condition to ensure good flour extraction and quality. gradually smaller corrugations are used (or a larger num-Depending on the quality of the steel and the type of ber of corrugations per inch of roll surface). Optimally milling technology used, corrugated rolls should be refur-conditioned wheat and the right corrugations, pressure, bished every 3-6 months of milling Other factors that in-and differential minimize splitting of the bran to particles fluence the need for refurbishing are roll surface alloca-of a size that can be sieved through with the flour. Good re-tion, feed rate per unit, severity of grinding, wheat sults in conventional milling are obtained when most of hardness, and presence of stones or other impurities in the endosperm free bran consists of large flakes. wheat. Recent advances in metallurgy that allow casting of The commercial flow should be designed to meet the re-harder outer surfaces for corrugated rolls extend the time quired capacity, wheat quality, and end products, and it is between refurbishing up to 8 months. based on specific machine surface values as shown in Even when the mix in the mill is changed drastically in Table 3 [56]. For example, the roll unit in the United States wheat size and kernels are smaller or larger than normal, allocates 0.3 inch of roll length per 100 pounds (cwt) of usually mills will continue using the existing corrugations, flour milled per 24 hours. Mills that use the metric system keeping many exiting variables unaltered. Generally, the would express the same roll units as 12.58 mm/100 kg gap between the rolls will be adjusted intuitively by the wheat/24 h. Conventionally with a longer break system, up miller based on his or her experience. A few studies were to six stages in hard wheat and seven in durum wheat conducted to evaluate the first roll action and the different TABLE 3 Mill Technical Specifications for Major Equipment for Different Kinds of Wheats' Wheat Hard Soft Durum Roll unit (mm) 10-15 10-13 16-20 Sifter surface (m 2) 0.055-0.081 0.083-0.088 0.086-0.093 Purifier width (mm) 3-70-38-12 aPer 100 kg processed wheat in 24 hours. Ref. 56." In Handbook of Cereal Science and Technology, Revised and Expanded. CRC Press, 2000. http://dx.doi.org/10.1201/9781420027228-7.