Wheat flours separation

Soft-wheat flours are sold for general family use, as biscuit or cake flours, and for the commercial production of crackers, pretzels, cakes, cookies, and pastry. The protein in soft wheat flour mns from 7 to 10%. There are differences in appearance, texture, and absorption capacity between hard- and soft-wheat flour subjected to the same milling procedures. Hard-wheat flour falls into separate particles if shaken in the hand whereas, soft-wheat flour tends to clump and hold its shape if pressed together. Hard-wheat flour feels slightly coarse and granular when mbbed between the fingers soft-wheat flour feels soft and smooth. Hard-wheat flour absorbs more Hquid than does soft-wheat flour. Consequently, many recipes recommend a variable measure of either flour or Hquid to achieve a desired consistency. 

There is another type of gluten available and that is produced in France by air classifying wheat flour. Air classification works by separating materials in an air stream on the basis of density. This air classified gluten has not been wetted and dried and behaves more like the gluten found in flour. 

Wafer Flour. Wafer flour is a type of biscuit flour with the same basic specification of low protein soft wheat flour with a low starch damage. Once again the required dough property is extensibility. The only differences are that if the protein is too low the wafer will be too soft to handle, and if the protein is too high the wafer will be too hard. The other important property is a resistance to gluten separation. Wafer flours are likely to be brown. 

Most of the applications of HPLC for protein analysis deal with the storage proteins in cereals (wheat, corn, rice, oat, barley) and beans (pea, soybeans). HPLC has proved useful for cultivar identihcation, protein separation, and characterization to detect adulterations (illegal addition of common wheat flour to durum wheat flour) [107]. Recently Losso et al. [146] have reported a rapid method for rice prolamin separation by perfusion chromatography on a RP POROS RH/2 column (UV detection at 230nm), sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), and molecular size determination by MALDl-MS. DuPont et al. [147] used a combination of RP-HPLC and SDS-PAGE to determine the composition of wheat flour proteins previously fractionated by sequential extraction. 

A method for determination of various types of peroxides consists of RP-HPLC separation and applying post-column UV radiation to convert the peroxide to H2O2, which may be determined by CLD with bis(2,4,6-trichlorophenyl) oxalate (140) in the presence of 2,4,6,8-tetrathiomorpholinopyrimido[5,4-(J]pyrimidine (194) as fluorescence enhancer. Dibenzoyl peroxide and f-butyl perbenzoate have LOD (SNR 3) 6.8 and 7.5 p.M, respectively, and linearity range from 40 to 400 p.M. The method was applied for determination of dibenzoyl peroxide used as whitener of wheat flour, after extraction with ethanol . See a similar method in Section VLB.3. 

In this paper, we will explore the measurement of and the basis for the cohesive and elastic properties of a commonly used component of foods that excels in these characteristics, wheat gluten. Gluten constitutes from 10 to 16% of wheat flour, from which it may be separated by Martin, batter, or Raisio processes (2, 3). The separated wheat gluten is 70 to 80% protein, of which 85% is insoluble in saline solution. We shall also seek to correlate some of the basic concepts developed in studies of gluten to other protein systems, such as those of soybean protein isolates and concentrates. 

Figure 6. Types of proteins in wheat flour as separated by solubility...

JA Prieto, A Ebri, C Collar. Optimized separation of nonpolar and polar hpid classes from wheat flour by solid-phase extraction. J Am Oil Chem Soc 69 387-391, 1992. 

Liquorice is a slightly unusual example of a starch gel instead of separating the starch, wheat flour is used directly. It is also a product where brown sugars and treacle are used. Liquorice paste is typically made from treacle, wheat flour, liquorice extract and caramel. Caramel in this context means the brown colour produced from sugar and not a form of toffee. Industrial caramel is made by the action of ammonium hydroxide on a carbohydrate, typically glucose syrup. The resulting product is not well defined chemically, and for this reason its use is recommended to be limited to 0.2% maximum. 

In contrast to natural structures the morphological features of structures in fabricated foods are in principle within our control. The source of the many structures of foods, even those made from a single raw material (e.g., wheat flour), lies in the ingredient mix and the fact that thermodynamic equilibrium is practically never required or achieved during processing. These metastable structures can be attained because they are favored kinetically, that is, the approach to equilibrium is slow. At any point during the development of a particular structure a process of shape stabilization sets in, usually by vitrification, partial crystallization, phase separation and/or formation of a network (Figure 12.5). 

This is a starch which is obtained by separating the gluten from wheat flour,... 

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)]... 

In 1928 the Wheat Flour Institute was formed. It is the educational division of the Millers National Federation. Its basic function is to halt the trend of declining per capita consumption of flour through education and basic product promotion. The Wheat Flour Institute joins bakers and millers, doctors, dentists, nutritionists, educators, research workers, and editors and writers to gain a merited place for bread on America s family table. In 1 year more than 5,000,000 separate pieces of educational literature were distributed by request from the Wheat Flour Institute. These numerous pieces of literature deal with subjects pertaining to the story of wheat and flour, good food, and human nutrition 37-41),... 

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