Fractionation of wheat proteins

Figure 7. Fractionation of wheat proteins on sepharose-CL4B columns by gel filtration chromatography in 0.125 trisborate buffer, pH 8.9 and 0.1% SDS (20).

Proteins from wheat flour Asymmetrical Fractionation of wheat proteins in the size range from 5 to 45 nm separation of gliadins from glutenin [K.-G. Wahlund, M. Gustavson, F. MacRitchie, T. Nylander, and L. Wannerberger,/. Cereal Sci. 23 113-119 (1996)]... 

Calcium stearoyl-2-lactylate—a recognized bread dough conditioner (24)—is known to complex with certain water-soluble fractions of wheat protein (3), but there is little hard evidence pointing to a direct interaction between it and gluten proteins on the order of that seen between the nonionic surfactants and gliadin. Some evidence (25) suggests that calcium stearoyl-2-lactylate interacts with gluten proteins in the presence of starch. 

Stevenson, S. G., and K. R. Preston. 1996. Flow field-flow fractionation of wheat proteins. Journal of Cereal Science 23 121-131. 

Truust H and Johansson G (1996) Fractionation of wheat proteins by counter-current distribution using aqueous two-phase systems containing propionic acid. Journal of Chromatography B 680 71-80. 

Proteins from wheat flour Asymmetrical Fractionation of wheat proteins in the size range from 5 to 45 nm separation of gliadins from glutenin. ... 

Proteins have been studied for a long time. Beccari published an account of his experiments to isolate gluten in 1747 In 1805 Einhof discovered that a fraction of wheat gluten was soluble, while in 1858 Denis showed that many proteins of both plant and animal origin were soluble in saline solutions. In 1859 Ritthausen started to prepare highly purified proteins, only to be criticised by Weyl for using alkali to extract the proteins. Weyl in his work used the Denis method of extraction with neutral salts. 

Wahlund, K.G., MacRitchie F., Nylander T., and Wannerberger, L. (1996). Size characterization of wheat proteins, particularly glutenin, by asymmetrical flow field flow fractionation. 

Wheat protein fractions Symmetrical Size distribution of wheat protein fractions (albumins and globulins, gliadins, glutenins) prepared by extraction influence of oxidation on size distribution of high-MW glutenin [S. G. Stevenson, T. Ueno, and K. R. Preston, Anal. Chem. 71 8-14 (1999)]... 

Pasaribu, S. J., J. D. Tomlinson, and G. J. McMaster. 1992. Fractionation of wheat flour proteins by size exclusion—HPLC on an agarose-based matrix. Journal of Cereal Science 15 121-136. 

The first two reports on the use of flow FFF for separating wheat proteins appeared in the literature in 1996 when researchers firom two independent laboratories reported characterization of wheat proteins from different varieties extracted by different methods and analyzed on two different types of flow FFF apparatus. Wahlund et al. - used asymmetrical flow FFF to examine proteins extracted firom two bread wheat varieties of different protein content using sequential extraction with increasing concentrations of dilute hydrochloric acid (HCl). Stevenson and Preston used symmetrical flow FFF to examine proteins extracted firom Katepwa, a high quahty bread wheat variety, using a modification of the traditional Osborne extraction procedure. Results from both studies showed that for the monomeric gliadin-type fractions ranged in size from 8 to... 

Field-flow fractionation has shown to be usefiil for systematically monitoring changes in molecular size distribution of wheat proteins, for example, those caused by treatment with... 

Continued improvements in FFF instrumentation, refinements in technique and hyphenation with detectors such as MALLS have broadened the application of this method and effectively elevated it from the status of possibly useful technique to a reliable applied research tool for assessing the size and shape of wheat proteins. For additional reading concerning FFF theory, principles, and applications, the reader is referred to other sections of this encyclopedia as well as to Field-Flow Fractionation Handbook edited by Schimpf et al. A review of the application of FFF to wheat protein analysis can also be found in Preston and Stevenson. 

Figure 2 Location of stabilizing disulfide bonds (schematic) in the two main fractions of wheat gluten proteins (a) gliadin and (b) glutenin. 

Figure 12. Effect of free radical scavenging by cysteine on distribution of glucosamine protein-starch linkages in soluble protein and insoluble residue fraction of wheat flour extrudates. Adapted from (4) with permission. Copyright Amer. Assoc. Cereal Chemists, 1996.

The glutelin fraction of cereal protein is more heterogeneous than the other storage proteins and consists of several different proteins. Wheat gliadin, for example, is separable into four major fractions a, j3, y and a> but, in all, the gliadin may have as many as 46 components revealed by gel electrophoresis... 

A fractionation of gluten proteins is possible by two-dimensional electrophoresis. Figure 15.3 provides a schematic overview of the position of the most important protein groups in a two-dimensional electropherogram. The pattern of glutenins of two wheat cultivars are shown in Fig. 15.4. 

Coeliac disease is an allergy to one specific protein in wheat - the gliadin fraction of wheat gluten. The result is a considerable loss of intestinal mucosa and flattening of the intestinal villi, so that the appearance of the intestine is similar to that seen in... 

Fine grinding and air classification make possible the production of some cake flour from hard wheat and some bread flour or high-protein fractions from soft wheat. AppHcation of the process theoretically frees the miller from dependence on different wheats, either hard or soft, that change each crop year. The problem is how to market the larger volume of low protein or starch fractions at prices adequate to justify the installation and operation of the special equipment (46). 

In our investigations, we also detected the sorption of isoPO from potato, Arabidopsis and wheat, by calcium pectate. Moreover, we observed the binding with calcium pectate of potato PO from the fraction of proteins ionically bound with cell walls. It is likely that the ability of some PO isoforms to bind with pectin ensures the spatial proximity of these enzymes to the sites of the initiation of lignin synthesis and that these "pectin-specific" isoforms take part in this process. 

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