Crumbs, structure

The method uses extra yeast and a higher temperature with just a single proof before baking. The finished bread is not very pleasant as the crumb structure is coarse with thick walls, and also it stales rapidly. 

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. 

In some cases proteases are added to open up the crumb structure. This is more likely to happen in North America than the UK. The response in the UK would probably be to use a weaker flour. 

A solid phase, as discussed in detail in Chap. 2, is composed of varying amounts of mineral and organic matter which influence the crumb structure and the binding capacity, by the association of clay minerals with organic matter of the solid. The ability of a solid phase to sorb organic pollutants is also influenced by variable system conditions and differing environmental conditions. 

Baking. Flour contains enzymes, the most important of which are amylases and proteases. However, the quantities of these enzymes are not always ideal for baking purposes, and supplementary enzymes are often added. Many potential applications of enzymes are being investigated to improve the properties of bread. Traditional applications of enzymes are for improvement of the dough, loaf volume, crumb structure, and shelf-life. The enzyme products used are free-flowing microgranulates that are easy to handle and freely mixed with flour. 

Assessment of the soil in terms of these criteria gives a very accurate picture of the state of the soil. In particular, the distribution of the crumb structure, roots and moisture very soon reveals where horizons that impede plant growth are present in the soil. 

When dead plant material is broken down by soil animals and microorganisms, it forms humus, which slowly releases minerals into the soil and makes nutrients available for plants. Humus can remain in the soil for hundreds of years. In a healthy soil, the organic humus and mineral particles stick together to form tiny crumbs a millimeter or so thick. These crumbs are held together by electrical attraction, and by organic glues produced by bacteria. The tiny pores in between this crumb structure form a kind of sponge that helps to retain water in the soil. 

Podzol-like soils formed in deciduous forests, where there is less resistant surface organic debris, are much less extracted. Deciduous trees assimilate more soil bases from the subsoil than do coniferous trees, and since the leaves decay more readily there is a constant return of bases from the subsoil to the surface, thereby offsetting in part the downward movement in the drainage. These podzol-like soils may have no bleached layer and much less distinct horizons than the true podzols. They are less acid, more fertile than the typical well-developed podzol, and the organic matter is more mixed with the soil mass. Typical podzols have little or no granular structure, whereas the gray-brown soils often have a fairly well-developed crumb structure. 

Table 20.11, taken from Cope, shows how an ash soil differs from a hypothetical fertile soil. It is light brownish-grey to dark purplish-grey and consists of more than 50% glassy material, mostly 20-200 m in diameter mixed with larger particles of ash and clinker. Ash soils have very poor crumb structure and low exchange capacity, as would be expected, since organic matter is absent. 

Dough conditioners. Dough conditioners or stabilisers and emulsifiers reduce the necessity for resting times and improve tolerance towards dough handling in the bakery equipment. The bread volume is increased and the crumb structure becomes finer and more uniform. In addition, dough conditioners emulsify any fat in the recipe (Tamstorf, 1983 Pyler, 1988). 

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