Types of Breads

Fig. 38.6. Three-dimensional configuration according to a non-metric multidimensional scaling applied to 24 types of bread differing in appearance as assessed by 12 panellists.

Many chemical reactions occur in the kitchen. For example, some types of breads, called yeast breads, rely on the chemical reactions of tiny microbes to make them look and taste the way they do. The microbes, in this case, are yeast spores mixed into the bread dough. Yeast spores are tiny living things that can only be seen under a microscope. When yeast is mixed into bread dough, they feed on the carbohydrates in the flour and produce carbon dioxide gas and alcohol. This process is called fermentation. 

Other types of bread, called quick breads, do not use yeast. These breads instead rely on the reaction between baking soda and an acid to rise. If baking soda is mixed with an acid, it makes... 

First, with constraints on resources always an issue, there is usually a need to balance effectively the range of pesticide residues screened for and the number of samples analysed. The sampling plan for the NZTDS was devised to look closely at foods that were more likely to contain pesticide residues. For example, previous NZTDSs had indicated that carbonated cola beverage was unlikely to contain pesticide residues and so only two composite samples were analysed. By contrast, bread often contains residues of organophosphorus pesticides and so eight samples of each of three different types of bread were analysed. 

To improve the quality of bread produced by modern methods, it is necessary to understand the chemistry of bread flavor. Therefore many studies have been undertaken to clarify the composition and formation of the flavors of different types of bread (1-5). 

Zinc absorption was measured from meals based on wheat bread. A lower absolute amount of zinc was absorbed from a low zinc white bread (72% extraction rate) than from a whole-meal bread with a higher zinc content (100% extraction rate). When the two types of bread where enriched with zinc chloride, more zinc was absorbed from the white bread. By increasing the zinc content of the whole meal bread in form of animal protein sources, such as milk and cheese, the absorption increased to the same level as that from zinc-enriched white bread. Addition of calcium in the form of milk products improved the absorption of zinc from a meal with whole meal bread. 

If in a text-book on the art of baking it was claimed that all types of bread, e.g. loaves of black bread, sponge-cakes and ginger biscuits, should be baked at the same oven temperature and for an equally long time, that book would probably not be a best-seller. This is in essence the concept of "standardized conditions". 

A Bloodhound BH 114 electronic nose was used to differentiate between different types of bread spoilage [34]. Microbial and enzymatic spoilage caused by lipoxygenase can be differentiated from one another and from unspoilt bread after 48 hours by using cluster analysis. This is achieved before visible spoilage signs. Analysis of the bread samples with GC-MS identified the spoilage volatiles and the volatiles from the unspoilt bread. 

A sandwich from Kelly s consists of one type of bread, one meat, and one cheese. ... 

Several other types of bread have been made successfully at Chorleywood using ascorbic acid as sole oxidant in an oxygen-enriched atmosphere including soft rolls, Viennas and hamburger buns. 

Starch degrades to dextrins, mono- and disaccharides at the relatively high temperatures to which the outer part of the dough is exposed. Caramelization and nonenzymatic browning reactions also occur, providing the sweetness and color of the crust. The thickness of the crust is dependent on temperature and baking time (Table 15.51) and type of baked product (Table 15.54). The composition of some types of bread is presented in Table 15.55. 

Table 15.55. Chemical composition of some types of bread...

NUTRITIVE VALUES OF BREADS AND RELATED ITEMS. Bread has often been called the staff of life. This implies that it supplies most of the required nutrients. While this characterization might have had some basis when it was applied to the ancient types of coarse, whole grain breads that sometimes contained malted or sprouted grains, it does not seem to be very applicable to the modern types of breads made from highly refined flours. 

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