Bread wheat

Weiss-blech, n. tin plate, -biechdose, /. tin can, tin box, tin. -blechwaren, f.pl. tinware, -blei, n. tin. -bleiche, /. bleaching, full bleach, -bleierz, n. white lead ore, cerussite. -biiitigkeit, /. leukemia, leucocythemia, -boden, m. Tech.) white ground, -brenneo, n, calcining at white heat, -brot, n. white bread, wheat bread. 

JUNTUNEN K S, MAZUR W M, LIUKKONEN K H, UEHARA M, POUTANEN K S, ADLERCREUTZ H C T, MYKKANEN H M (2000) Consumption of wholemeal rye bread increases sermn concentrations and urinary excreation of enterolactone compared with consiunption of white wheat bread in healthy Fiimish men and women, British Journal of Nutrition, 84, 839 6. 

In inner layers, changes are much the same as during boiling. Tocopherols and tocotrienols present in wheat and rye are partially destroyed during baking. In ordinary wheat bread, losses of a-tocopherol amount to about 25%, but in the case of rye bread, prepared by traditional technology, a loss of about 50% was reported (Piironen et al, 1987). Losses of natural antioxidants in coffee brews and tomato puree were also observed (Nicoli et al, 1997). 

Fig. 23.1 Schematic flow diagrams showing which major steps were present in five different supply chains for organic wheat bread from leaflets no. 9 and 10, Organic...

Rye, like wheat, has bread making potential and rye dough can develop however, rye bread does not have the potential for expansion that wheat bread does. 

Rye Breads. The British consumer, in general, does not like the taste of rye bread. Most of the rye bread made in the UK is for the benefit of immigrant communities that traditionally eat rye bread. In Scandinavia, Central and Eastern Europe, rye breads are eaten as a delicacy not as a substitute for wheat bread. It has been recorded that the Vikings brought rye bread to Britain but they were an immigrant group. 

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. 

The brown or whole meal bread diets employed by previous investigators were often variable in calcium and phytate intakes, not only between individuals, but by the same individual subjected to different diet treatments. Nevertheless an estimate of the molar ratio of phytate/calcium in the brown or whole meal bread diets used by McCance and Widdowson (UO), Walker et al. (11) and Reinhold et al. (2, 12) is 0.25 or greater. These investigators observed either negative or less positive calcium balance and apparent absorption when the brown bread diets were consumed compared to white bread diets with phytate/calcium molar ratios less than 0.05. Our results support their findings. Reinhold et al. (2) and McCance and Widdowson (33) used sodium phytate in some studies as well as whole wheat bread and observed similar results. 

More than 40 years ago, calcium absorption from brown (whole wheat) bread which was fed to human subjects was found to be poorer than was that when white (extracted wheat flour) was fed 04,5). Since then, many studies have sought to define the extent of inhibition of calcium intestinal bioavailability by various forms of dietary fiber with mixed results and conclusions (6-18). 

Defatted flours are especially attractive as protein sources, since 10-12% substitution of wheat flour with 50% protein flour will raise total protein content of typical wheat breads by approximately 50%, and 25% substitution will almost double the protein content of cookies. Preparation of protein-enriched breads has been reported in the literature using soy flours and protein concentrates (25), peanut flours and peanut protein concentrates C26, 27), glandless cottonseed flours, concentrates and isolates (28), sunflower seed flours and seed protein concentrates (27) and sesame flours and protein concentrates (26). 

Sandberg, G. Hallmans, and H HV201 Andersson. Substrates available for colonic fermentation from oat, barley and wheat bread diets. A study in ileostomy subjects. Br J Nutr 1996 76(6) HV202... 

Juntunen, K.S., Mazur, W.M., Liukkonen, K.H., Uehara, M., Poutanen, K.S., Adlercreutz, H.C., and Mykkanen, H.M., Consumption of wholemeal rye bread increases serum concentrations and urinary excretion of enterolactone compared with consumption of white wheat bread in healthy Finnish men and women, Br. J. Nutr., 84, 839, 2000. 

Kaack, K., Pedersen, L., Laerke, H., Meyer, A. (2006). New potato fibre for improvement of texture and colour of wheat bread. Eur. Food Res. TechnoL, 224,199-207. 

For estimating the contribution of volatile compounds to bread aroma Rothe and coworkers (S) defined "aroma value" as the ratio of the concentration of some volatile compounds to the taste threshold value of the aroma. This concept was further developed by Weurman and coworkers (9) by introducing "odor value", in which aroma solutions were replaced by synthetic mixtures of volatile compounds in water. These mixtures showed the complexity of the volatile fractions of wheat bread, because none of them resembled the aroma of bread. Recently two variations of GC-sniffing were presented (10-11), in which the aroma extract is stepwise diluted with a solvent until no odor is perceived for each volatile compound separately in the GC effluent. The dilution factors obtained indicate the potency of a compound as a contributor to the total aroma. 

The characteristic aroma of wheat bread crust has been attributed to 2-acetyl-1-pyrroline, and its formation depends on the presence of bakers yeast [31]. In model systems it was demonstrated that the acetylpyrroline is formed from the reaction of proline with pyruvaldehyde or dihydroxyacetone. Other compounds with bread-like aromas formed in the reaction of proline with pyruvaldehyde include l-acetonyl-2-pyrroline and 2-acetyltetrahydropyridine (Scheme 12.5). These compounds are unstable, which explains why the characteristic aroma of freshly baked bread disappears quickly during storage. 

Grahamite rooming houses sprang up, where boarders could thrive on meatless meals consisting of coarse whole-wheat bread, uncooked vegetables, oatmeal, and barley — not unlike... 

Several essential amino acids have been shown to be the limiting factor of nutrition in plant proteins. In advanced countries, the ratio of vegetable proteins to animal proteins in foods is 1.4 1. In underdeveloped nations, the ratio is 3.5 1. which means that people in underdeveloped areas depend upon vegetable proteins. Among vegetable staple foods, wheat easily can be fortified. It is used as flour all over the world. L-Lysine hydrochloride (0,2% ) is added to the flour. Wheat bread fortified with lysine is used in several areas of the woilcl in Japan it is supplied as a school ration. 

H4PteGlu, wheat bread Hepes/Ches buffer, (250 X 4.6 mm. 

A first approach to analyze such volatiles is the application of the AEDA on extracts prepared by dynamic headspace extraction. An apparatus used for the extraction especially of solid foods is shown in Figure 5 [55]. The powdered material is placed into a rotating cylinder and the volatiles are continuously flushed onto a polymer material (Tenax( )) by using a stream of helium (1 L/min). After 3 hr the volatiles are desorbed from the polymer by elution with a small amount of diethyl ether and evaluated by AEDA after concentration. Since different yields may change the composition of the volatiles during headspace extraction [7], it is essential to sensorially evaluate the flavor of the extracts in comparison with the food flavor itself. The following examples show applications of this method on fresh and stored wheat bread crust [55] and on fresh rye bread crust [P. Schieberle and W. Grosch, unpublished results]. 

On the basis of high FD-factors (Table 3) the sensory significance of 3-methylbutanal and 2-acetyI-l-pyrroIine with malty, roasty odors previously identified as the key odorants in fresh wheat bread crust [21] was established. During storage for 4 days the FD-factors of both odorants decreased significantly, while especially butanoic acid (rancid) and (E)-2-nonenaI remained unchanged. The fatty, green note of the latter odorant especially contributes to the stale note detectable in the overall crust flavor of the stored wheat bread. 

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