Sour Breads

The organic acids generated by fermenting bacteria such as acetic, lactic, hydroxya-cetic, formic, pyruvic, etc., are the main flavor precursors. Acetic add is considered the main acid. It improves dough characteristics, speeds up fermentation, and affects final bread properties. It is generated mainly from maltose and other simpler carbohydrates. 

The miCToorganisms that ferment sourdoughs act as leavening agents, improving bread volume. An excessive inocula concentration results in high dough acidification 

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Predict the reaction of acid phosphate, soda water, sour bread, basic lead acetate, sour wine, tart preserves, pickles. 

According to end use, wheat is classified as soft, hard, and durum. The first two classes are almost always dry-milled into refined flour for the manufacturing of fermented and chemical-leavened bakery products such as breads, cakes, crackers, cookies, and flour tortillas (Figure 1.8). Durums are dry-milled into coarse refined meals called semolina, ideally suited for manufacturing of long and short pasta products. Rye flour is usually mixed with wheat flour for the production of fermented breads including sour breads, especially in Germany, Poland, Ukraine, and other European countries. 

Lactic Acid B cteri. The lactic acid bacteria are ubiquitous in nature from plant surfaces to gastrointestinal tracts of many animals. These gram-positive facultative anaerobes convert carbohydrates (qv) to lactic acid and are used extensively in the food industry, for example, for the production of yogurt, cheese, sour dough bread, etc. The sour aromatic flavor imparted upon fermentation appears to be a desirable food trait. In addition, certain species produce a variety of antibiotics. 

Four characteristics of odor are subject to measurement by sensory techniques intensity, detectability, character (quality), and hedonic tone (pleasantness-unpleasantness) (16). Odor intensity is the magnitude of the perceived sensation and is classified by a descriptive scale, e.g., faint-moderate-strong, or a 1-10 numerical scale. The detectability of an odor or threshold limit is not an absolute level but depends on how the odorant is present, e.g., alone or in a mixture. Odor character or qualit) is the characteristic which permits its description or classification by comparison to other odors, i.e., sweet or sour, or like that of a skunk. The last characteristic is the hedonic type, which refers to the acceptability of an odorant. For the infrequent visitor, the smell of a large commercial bread bakery may be of high intensity but pleasant. For the nearby resident, the smell may be less acceptable. 

Sauermachen, n. acidification, sauermachend, p.a. acidifying, s uem, v.t. acidify, acidulate sour leaven (bread). — v.i. sour. 

Sour dough bread is made all over the world in both primitive and advanced societies. In primitive societies there is no alternative, but in advanced societies sour dough bread is made for its special flavour. Sour... 

Sour dough bread has a range of flavours that are not present in other bread also it keeps relatively well. The keeping properties, no doubt, originate from some of the products of the side-reactions that have taken place in the dough. There is no need to add propionic acid as a mould inhibitor as some is likely to be present naturally. Quite possibly, some of the substances produced by the fermentation would not be permitted as additives ... 

Types of Rye Bread. The usual descriptions are logical. Rye bread is bread made solely from rye flour, rye/wheat bread contains a minimum of 50% of rye flour while wheat/rye bread contains not less than 50% wheat flour with not less than 10% of rye flour. Some recipes for San Francisco sour dough bread have a proportion of rye flour. No doubt, originally, the prospectors used what ever was available. 

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. 

Some sour dough bread is made by using commercial yeast but with a proportion of genuine sour dough. Ordinary baker s yeast is at a disadvantage in rye sour dough because the low pH that is essential for rye bread is not the optimum pH for the yeast. 

Triticale flour has been extensively tested in Poland, a country where rye bread is traditional. The best results were obtained by using 90% triticale flour with 10% rye flour. The rye flour was made into a flour brew for 24 hours at 28-29°C. Half the triticale flour was made into a sour dough for 3 hours at 32°C followed by mixing with the rest of the ingredients plus 1.5% of salt on the flour weight. The bread was then scaled and proved for 30 min at 32°C followed by baking at 235-245°C. 

Traditional pitta bread is made by a sour dough process but it can be made using manufactured yeast. If the sour dough process is used a relatively large portion of sour dough (approximately 20%) is used, giving a more rapid fermentation than most sour dough products. 

There is a view that muffins originated in Wales. They were originally a sour dough flat bread. They seem to have disappeared from British life, except in a nursery rhyme. Presumably the original product had a short shelf life. The sort of product now sold as an English muffin has overcome some of these problems. The modem product is a disc shaped product about 7-10 cm in diameter and 2 cm high. 

Acrolein has been detected in effluent water streams from industrial and municipal sources. Municipal effluents from Dayton, Ohio, for example, contained between 20 and 200 pg acrolein/L in 6 of 11 analyzed samples (USEPA 1980 Beauchamp et al. 1985). Acrolein is also a component of many foods, and processing may increase the acrolein content (USEPA 1980). Acrolein has been identified in raw turkey, potatoes, onions, coffee grounds, raw cocoa beans, alcoholic beverages, hops (USEPA 1980), white bread, sugarcane molasses, souring salted pork, and cooked bluefin tuna (Thunnus thynnus) (Beauchamp et al. 1985). 

Unfortunately, to be effective against microorganisms in bakery products, acetic acid concentrations must be so high that an overly sour taste is imparted to the products. Sodium diacetate, however, can be used in small concentrations in bread and rolls to control rope and molds. Traditional concentrations of the acetate are 0.4 part to 100 parts of flour. During recent years, the propionates have largely displaced sodium diacetate for this use. 

O Burnt, pungent, fruity F Sour, sweet, fruity O Caramellic-sweet, but rather pungentjof good tenacity F First sour, then sweet, caramellic--fruity, bread-like, depending upon the concentration used. Sour taste mostly noticed in high concentration of the material. 

Mercury, or Mercurial Water, is that water Sulphur that flour, which by a long fermentation, becomes sour and are made into leaven, with which Gold and Silver are made. And as the leaven may be multiplied eternally, and may serve always as a material for making bread, so the Philosophical Medicine may also be multiplied, and serve eternally as the leaven for making Gold. 

Rye is grown mainly in the northeastern countries of Europe and in some locations in North America and Argentina.1 Rye is used mainly for human consumption and is the principal flour used in sour dough breads and in crisp bread. 

Acrolein has been identified in foods and food components such as raw cocoa beans, chocolate liquor, souring salted pork, fried potatoes and onions, raw and cooked turkey, and volatiles from cooked mackerel, white bread, raw chicken breast, ripe arctic bramble berries, heated animal fats and vegetable oils, and roasted coffee (Cantoni et al. 1969 EPA 1980, 1985 IARC 1985 Umano and Shibamoto 1987). Sufficient data are not available to establish the level of acrolein typically encountered in these foods. Trace levels of acrolein have been found in wine, whiskey, and lager beer (IARC 1985). Further information regarding the occurrence of acrolein in food and related products is provided by EPA (1980). 

The meals were breakfast meals, composed of sour milk, white bread and bran or bread with bran in it. 

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