Starch extraction

This was previously used as a herbicide, and attention has been directed to its degradation in storage areas or where it has been spilled. A strain of Clostridium bifermentans KMR-1 (that is protected by a U.S. patent) was unable to use dinoseb as carbon or energy source. In the presence of a starch extract, however, a low level of transformation was observed, and the products could subsequently be mineralized by aerobic bacteria (Hammill and Crawford 1996). These observations have been extended to the remediation of soil slurries from a contaminated site by adding phosphate and starch waste that achieved anaerobic conditions, and inoculation with a culture from a pilot-scale... 

The development of a by-production system could further minimize the cost of such plant-derived products. For example, potatoes are the raw material for the production of technical grade starch. During this process, soluble proteins are separated by heat treatment and sold as animal fodder. Recombinant proteins could be produced in transgenic potato tubers as a by-product of starch extraction, and this would be useful for proteins produced in large amounts with a low commercial impact, like structural fiber proteins. 

Kozlov, S. S., Blennow, A., Krivandin, A. V., Yuryev, V. P. (2007). Structural and thermodynamic properties of starches extracted from GBSS and GWD suppressed potato lines. Int J. Biol Macromol, 40,449 60. 

Yusuph, M., Tester, R. F., Ansell, R., Snape, C. E. (2003). Composition and properties of starches extracted from tubers of different potato varieties grown under the same environmental conditions. Food Chem., 82,283-289. Zhu, Q., Bertoft, E. (1996). Composition and structural analysis of alpha-dextrins from potato amylopectin. Carbohydr. Res., 288, 155-174. 

Critically analyzes various barley starch extraction techniques and suggests an improved technique to maximize yield. 

Reports the dough washing procedure for wheat starch extraction. 

Mohammadkhani, A., Stoddard, F.L., Marshall, D.R., Uddin, M.N., and Zhao, X. 1999. Starch extraction and amylose analysis from half seeds. Starch 51 62-68. 

Amylose content determines the degree of translucency of the endosperm (hence the name waxy when amylose is absent), and it affects the cooking and eating qualities of the grains and the industrial properties of the starch extracted from those grains. 

Figure 12.6 Changes in granular structure of cassava starch extracted from roots (a) planted during the rainy period and harvested at 6 months (b) planted during the rainy period and harvested at 12 months (c) planted during the dry period and harvested at 6 months (d) planted during the dry period and harvested at 1 2 months, when observed by hot-stage microscopy at different temperatures.

Type of Starch Extracted from Granule shape Granule size (pm)... 

In order to relieve the stresses of compression at higher densities by thermoplastic processes instead of with wire or twine, several conditions must occur. A balance between the pressure, and retention time must be found so that the material is exposed to temperatures of 200° to 300°F (93-150°C), and pressures of 1000 psi to 1500 psi (6.9-10.3 MPa) at moisture levels of 12 to 25 (9, 10). Moisture and agglutinant substances such as soluble sugars, starches, extractives, phenolic acids and lignins which will plasticize at these conditions must be evenly distributed throughout the material. The geometry of the material must allow a uniform fiber matrix and intimate contact between adhesive surfaces during compression. 

Starch factories need industrial water for flotation and washing of potatoes and for starch extraction. Water for extraction should be of drinking water quality. 

Figure 2 Size-exclusion chromatograms of lightly hydrolyzed starch extracted with mixtures of ethanol-water at different ratios. Determination of limiting solubility. Columns, Shodex S803/S801. Solvent, water at 60°C, 1mlmin Detection, refractometer. Calibrants, Shodex kit, Pullulan, P802.

The tropical plant cassava has tubers rich in starch but low in protein. Dried cassava meal and by-products from starch extraction are used in animal feeds, but they must be prepared in such a way that cyanogenetic glucosides are inactivated. 

Leaves and subterranean plant organs are additional sources of protein materials. Potato proteins are largely available as a by-product of the starch extraction. A promising source of soluble proteins is represented by the leaves of many species leaves contain about 80-90% water and 10-20% organic material, a small part of this (10-30%) is made of proteins. About 50% of the proteins are water soluble and can be extracted and purified as a crystalline protein fraction with a molecular weight in the range 10-60 kDa, suitable for food and cosmetic purposes (leaf protein concentrate) (18). 

The cereal seeds, tubers, starch storage roots, and bean/pea seeds are directly consumed as food in human diet or animal feed and are used as a source of starch. Extracted starch can be used to produce starch derivates or hydrolyzed to produce soluble sugars, food additives, or glucose syrup. Also, extracted starch can be used for other applications in nonfood industries (Nghiem et al. 2011). For example, it is used as a thickener and as a source of renewable raw material for bioethanol production. The major source of starch for the world market is cornstarch holding more than 80 % of the market, but wheat, potato, cassava or tapioca, and to a lesser extent rice and sweet potato starches are also commercialized (Thomsen et al. 2008). 

Foam fractionation is a relatively inexpensive technique for protein separation. Most studies in the literature are, however, experimental and very few report on industrial appUcations. Among other appUcations, foam liaclionation has been used to separate wheat flour proteins, ovalbumin, lysozyme, egg albumin, milk proteins (e.g., beta-casein, bovine lactoferrin, bovine serum albumin, alpha-lactalbumin, and beta-lactoglobulin) and potato protein from potato juice waste water after starch extraction (Weijenberg et al., 1978 Keller et al., 1997 Hossain and Fenton, 1998 Brown et al., 1999 Wang and Liu, 2(X)3 Wang etal., 2009). 

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