Wheat, protein content

Protein content Wheat Beef Cow s Fodder Yeast from... 

Hard red winter (HRW) is an important bread wheat that accounts for more than 40% of the United States wheat crop and wheat exports. This fall-seeded wheat is produced in the Great Plains, which extend from the Mississippi River west to the Rocky Mountains, and from the Dakotas and Montana south to Texas. Significant quantities are also produced in California. HRW has moderately high protein content, usually averaging 11—12%, and good milling and baking characteristics. 

When compared to whole meal rye flour (280 kcal/1160 kJ) and to wheat flour (320 kcal/1320 kJ), phloem powder (140 kcal/580 kJ) contains approximately 50% less energy. As is typical for all flours, phloem powder also contains a low amount of fat (total amount 2.3 g/100 g). The protein content of phloem is only 2.5 g (per 100 g), whereas the respective amount in whole meal rye flour is 8.8 g and in wheat flour 12.1 g. The content of carbohydrates in phloem ( 30 g/100 g) is about 50% less than in rye (55 g) and wheat flours (59 g). The relatively low energy, protein and carbohydrate content of phloem when compared with commonly used flours, is related to its high content of different fiber. Detailed nutritional data for phloem and phloem breads used in our trial are presented in Table 14.1. 

Table 1. The composition of neutral sugars and content of anhydrogalacturonic acid (%) in XRPP extracted with pH 1.6 HCl solution at 85° C for 4 h (1 g wheat straw/100 mL extractant) from defatted, protein-free wheat straw.

Our group has used twin-screw extrusion to produce many texturized whey-fortified puffed snacks. Whey protein has been blended with barley flour, com meal, rice flour, and wheat starch prior to extrusion, leading to corn puffs with a protein content of 20% instead of the usual 2% (Onwulata et al., 2001a). 

This would have a substantial proportion of Canadian wheat and would be suitable for any long process. It can be used to make ordinary bread but is more likely to be used to make Viennas or rolls. The protein content could be as high as 14% with a water absorption of 62-64%. This product would have a high tolerance in the bakery. One use would be with a suitable improver to produce very well blown up rolls. 

This grade has less imported wheat and a lower protein content than the top grade but more than the baker s grade. The protein content might be 13%. 

This is the standard grade used by small bakers to make bread. There will be sufficient third country wheat, probably Canadian, for it to work in a long process such as bulk fermentation. The protein content would be around 12%. 

This is the flour that would go into the Chorleywood bread plants. It would be based on all EU wheat (in most years all English). The protein content would probably be 10.6 11.5%. This flour could also be used for making puff pastry. 

The Kjeldahl titration remains the chemical method for determining the nitrogen and hence protein content of wheat or flour. The method works... 

Wafers are normally made from a low to medium protein soft wheat flour. Too high a protein flour produces too hard a wafer. Conversely, too low a protein content will give very fragile wafers. 

Figure 4. Protein content (%) of sugar cookies prepared from defatted peanut, soybean, and cowpea flours at 0, 10, 20, and 30% wheat flour replacement levels. Reproduced with permission from Ref. 3. Copyright 1978, American Association of Cereal Chemists.

Field Pea Flours in Pasta. Incorporation of non-wheat flours into noodles improves the protein content and quality, but may have an adverse effect on the flavor and texture of the pasta. Hannigan (38) reported that 10% substitution of wheat flour with pea or soy flour resulted in satisfactory quality of Japanese Udon noodles. 

Nielsen et al. (39) used pea flour and pea protein concentrate, both cooked and raw, in noodles and spaghetti. The pasta was made from composite flours prepared by blending 33% pea flour with 67% wheat flour or 20% pea concentrate with 80% wheat flour. Protein content of the fortified noodles was approximately one-third higher than the wheat flour noodles. Addition of pea flour reduced the cooking time, but resulted in a softer product and lower yield than the wheat pastas. Precooking the pea flour improved flavor and decreased noodle dough stickiness, but the texture and yield of the cooked pasta was still less than that of wheat products. 

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). 

Wheat, rye, and barley have a common ancestral origin in the grass family. Oats are more distantly related to the analogous proteins in wheat, rye, and barley and the oat prolamins (avenin) have substantially lower proline content. Avenin accounts for 5-15% of the total protein in oats, whereas in wheat, barley, and rye, prolamins constitute 40-50% of the total protein (Kilmartin et al., 2006). Some investigators believe that there are similarities between the protein structure of oats and some wheat-like sequences, which may indicate that large amounts of oats could potentially be toxic to patients with celiac disease. However, the putative toxic amino acid sequences are less frequent in avenin than in other prolamins, which explains the less toxic nature of oats (Arentz-Hansen et al., 2004 Ellis and Ciclitira, 2001, 2008 Shan et al., 2005 Vader et al., 2002, 2003). 

Potatoes are an excellent source of carbohydrates and contain significant amounts ofphosphorus, potassium, calcium, and vitamins, especially vitamin C. Potato protein content, at over 10%, is relatively close to that of wheat flour (11%) also, thanks to their lysine, methionine, cystine and cysteine contents, potatoes are a valuable supplement to cereal proteins. For instance, potatoes provide a significant source of proteins (10-15% of total requirements), a major source of vitamin C, an important source of energy, and also minerals like iron and other vitamins such as thiamin, nicotinic acid, riboflavin, and pro-vitamin A (p carotene) (Salunkhe and Kadam, 1991). 

For the application of indirect calibration methods, one should have several samples available with known constitution. These samples should be of exactly the same type as the unknown sample. For example for the determination of the fat, water and protein content in wheat by near infrared reflectance spectrometry, one should have available a number of wheat flour samples of which the amount of fat, water and protein is known, or determined by a conventional method. 

In trading grain, for example, if exported wheat is analyzed by both buyer and seller for protein content, they should be confident that they will obtain comparable measurement results in other words, results for the same sample of wheat should agree within the stated measurement uncertainties. If the results do not agree, then one party or the other will be disadvantaged, the samples will have to be remeasured, perhaps by a third-party referee, at cost of time and money. Different results could arise from genuine differences in the value of the quantity for example, the wheat could have taken up moisture or been infected with fungus, so it is important that the analysis does not lead to incorrect inferences. 

---