Dough proteins

Oilseed proteins are used as food ingredients at concentrations of 1—2% to nearly 100%. At low concentrations, the proteins are added primarily for their functional properties, eg, emulsification, fat absorption, water absorption, texture, dough formation, adhesion, cohesion, elasticity, film formation, and aeration (86) (see Food processing). Because of high protein contents, textured flours and concentrates are used as the principal ingredients of some meat substitutes. 

The role of yeast in fermenting dough maturation is even less clear. The alcohol and carbon dioxide developed during fermentation must influence the elastic properties of the protein matrix. However, experimental procedures that would permit this to be checked in the absence of yeast have not been developed. 

Tetrasodium pyrophosphate is used as a pH buffer (a substance that maintains a particular acidity level), and as a dough conditioner in soy-based meat alternatives. It promotes binding of proteins to water, binding the soy particles together, and is used for the same purpose in chicken nuggets and imitation crab and lobster products. 

Fumaric acid breaks the sulfur-to-sulfur bonds in the elastic protein gluten in bread doughs. This makes the doughs more machine-able. It also is a key ingredient in rye and sourdough breads—it makes them sourer. 

Gluten is used to refer to dried wheat gluten, all the proteins in a dough, and by chemists as a class of proteins. 

Enzymic actions that depolymerise proteins such as the high molecular weight glutenins will cause the viscosity of the dough to drop. This outcome is predictable on the basis of polymer science. 

Dried Gluten. This material is sold as vital wheat gluten, it is produced by a scaled up version of the process for producing wet gluten for flour testing. A flour and water dough is made and then washed to remove the starch, the soluble proteins and the pentosan-based gum fraction. This latter fraction is an example of a non-starch carbohydrate. 

Soy beans are another crop that will not grow in Europe. The soy bean is used as a source of both protein and vegetable oil. Enzyme active soy flour has been used in bread since the 1930s. The flour contains a lipoxygenase system that assists with the development of the dough and slightly bleaches the bread. Soy flour is classed as an ingredient rather than an additive. 

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. 

These tests measure the way in which flour behaves when it has been made into a dough. They work with a specially made dough and give an indication of how the flour will behave in that situation. This sort of information is inherently more useful than a mere protein content. 

Rye Proteins. While rye is the only European cereal able to completely replace wheat in bread, rye protein is not as effective as wheat protein. One reason for this is that as much as 80% of the protein in a rye sour dough is soluble compared with 10% of soluble protein in a wheat dough. One factor that inhibits the formation of a gluten-like complex is the 4-7% of pentosans present, which bind water and raise the viscosity of the dough. The crumb structure is then formed from the pentosans in combination with the starch. 

Pretzels are made from a very stiff dough that is made from a low protein soft wheat flour, e.g. one made from a soft white winter wheat. The water level would be only 38 42%, with 0.25% yeast and 1% shortening, 1 % salt and 1 % dry malt. The dough would be mixed in a Z blade mixer and then left to prove for up to 4 hours. 

Initial work to establish chip preparation conditions showed that end product characteristics were influenced by meal particle size, by the amount of water added to form the dough, and by the length of time the dough was mixed (1). A very acceptable product was achieved with these process conditions a blend of particle sizes most of which were in the 14-30 mesh range, an 18% added water level, and a mixing time of 5 min. The final product had a crisp texture, a typical roasted peanut flavor, and was quite similar in composition to full-fat roasted peanuts. Chips contained about 49% oil, 27% protein, and 1% moisture. 

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