Starch-containing plants wheat

Starch-containing plants Another potential ethanol feedstock is starch. Starch molecules are made up of long chains of glucose molecules. Hence, starch-containing materials can also be fermented after the starch molecules have been broken down into simple glucose molecules. Examples of starchy materials commonly used around the world for ethanol production include cereal grains, potatoes, sweet potatoes and cassava. Typical cereal grains commonly used for ethanol production in the EET are rye and wheat. 

The polysaccharide starch is found in most plants as a storage compound however, only five plants, namely maize, rice, wheat, potatoes, and cassava account for the majority of worldwide produced starch-containing plants. Roughly 2.7 billion tons of these crops are annually harvested. The class of sugar-containing crops contains only two plants namely sugar cane and sugar beet of which about 2 billion tons are... 

Starch is not a pure substance. The term refers to a group of polysaccharides found in plants. Starches serve as a major method of food storage in plant seeds and tubers. Corn, potatoes, wheat, and rice all contain substantial amounts of starch. These plant products serve as major sources of needed food energy for humans. Enzymes in the digestive system catalyze the hydrolysis of starch to glucose. 

Sugar containing plant material can be used without chemical pretreatment either directly as mash or after extraction with water. Examples are fruits, sugar beets, sugar cane, wheat soi hum, and so on. Starch containing agricultural commodities or waste products is pretreated with enzymes. Cellulose materials, such as wood, are cooked with acid to break up the polymeric carbohydrate bonds and to produce monomeric or dimeric sugars. 

Starch is a widely distributed material, occurring in the roots, seeds and fruits of plants. Seeds usually contain 40—70% starch whilst roots and fruits contain about 5-25%. The principal commercial source of starch is com sources of lesser importance include tapioca, wheat and potato. In the extraction of starch, the plant material is ground with water the resulting slurry is filtered to remove coarse tissue fragments, and a suspension of starch granules is obtained. The granules are collected by centrifuging and dried in warm air. 

The quantity of barley starch produced around the world is very little when compared to starch production from corn, wheat, rice, potato or tapioca. There are only a few processing plants around the world that produce starch concentrate or purified starch from barley. Barley starch concentrates containing up to —78% (dry basis) starch are now produced in North America by milling and air-classification of barley grains. Milling disintegrates the grain into fine particles and air-classification separates them on the basis of differences in density, mass and projected area in the direction of air... 

Starch is the main carbohydrate found in the seeds and roots of plants. Com, rice, wheat, and potatoes are common foods that contain a great deal of starch. 

The starch plant for continuous sweet syrup production consists of a container for summer wheat, mill, fermenter, exchangers, bioreactors, and filter as individual process stages, or equipment items as shown in Fig.l(a),(b)and Fig.2. The overall mass balance... 

The most common sources of starch in various regions of the world are potato, maize, cassava (manioc, tapioca, yucca), and rice. Popularity of a given starch and starchy plants do not go together. For instance, in many regions of the world wheat and rye are very commonly used. Wheat starch is only randomly isolated, and rye starch is only exceptionally available. Rye grains contain mucus, which seriously obstructs isolation of starch from this source. 

---