Flour niacin

The enrichment program followed in the United States is (/) the enrichment of flour, bread, and degerminated and white rice using thiamin [59-43-8] C 2H y N O S, riboflavin [83-88-5] C2yH2QN4Na02P, niacin [59-67-6] CgH N02, and iron [7439-89-6]-, (2) the retention or restoration of thiamin, riboflavin, niacin, and iron in processed food cereals (J) the addition of vitamin D [67-97-0] to milk, fluid skimmed milk, and nonfat dry milk (4) the addition of vitamin A [68-26-8], C2qH2qO, to margarine, fluid skimmed milk, and nonfat dry milk (5) the addition of iodine [7553-56-2] to table salt and (6) the addition of fluoride [16984-48-8] to areas in which the water supply has a low fluoride content (74). 

Some of the nutrients lost when the wheat germ and bran are discarded are returned to the flour by adding small amounts of vitamins and minerals. Among the nutrients most commonly added are niacin, thiamine, riboflavin, folic acid, iron, and calcium. 

White and brown flour in the UK have to be fortified with calcium, iron, thiamine (vitamin Bl), and niacin (vitamin B3 also known as nicotinic acid) as follows flour should contain not less than 235 mg per 100 g and not more than 390 mg per 100 g calcium carbonate, iron not less than 1.65 mg, thiamine (vitamin Bl) not less than 0.24 mg, and nicotinic acid not less than 1.6 mg or nicotinamide (which is nutritionally equivalent to nicotinic acid) not less than 1.60 mg. 

Niacin is found in many foods, including corn. The niacin in corn, however, cannot be absorbed in the intestinal tract. In regions of the world where corn is a major part of the diet, niacin deficiency can occur. If you add calcium oxide or wood ash to the water in which you boil corn, the resulting basic solution allows the niacin to be absorbed. The flour for making corn tortillas is commonly prepared using this method. 

Oxidation of nicotine with chromic acid led to the isolation of pyridine-3-carboxylic acid, which was given the trivial name nicotinic acid. We now find that nicotinic acid derivatives, especially nicotinamide, are biochemically important. Nicotinic acid (niacin) is termed vitamin B3, though nicotinamide is also included under the umbrella term vitamin B3 and is the preferred material for dietary supplements. It is common practice to enrich many foodstuffs, including bread, flour, corn, and rice products. Deficiency in nicotinamide leads to pellagra, which manifests itself in diarrhoea, dermatitis, and dementia. 

Nicotinic acid and nicotinamide, members of the vitamin B group and used as additives for flour and bread enrichment, and as animal feed additive among other applications, are made to the extent of 24 million pounds (nearly 11 million kilograms) per year throughout the world. Nicotinic acid (pyridine-3-caiboxylic acid), also called niacin, has many uses. See also Niacin. Nicotinic acid is made by the oxidation of 3-picolme or 2-mcthyl-5-cthylpyridine (the isocinchomcnc acid produced is partially deearboxylated). Alternatively, quinoline (the intermediate quinolinic acid) is partially deearboxylated with sulfuric add in the presence of selenium dioxide at about 300° C or with nitric acid, or by electrochemical oxidation. Nicotinic acid also can be made from 3-picoline by catalytic ammoxidation to 3-cyanopyridine, followed by hydrolysis. 

Enrichment. Vitamins and minerals, such as vitamin D, thiamin, and niacin, are added to fortify milk and flour. 

The Federal Enrichment Act of 1942 required the millers of flour to restore iron, niacin, thiamin and riboflavin lost in the milling process. Enriched flours and baked goods made from them are now excellent sources of niacin. Niacin may also be found in meat, poultry, fish, whole grains, and peanut butter. Besides direct niacin intake, humans can convert the amino acid tryptophan to niacin. Many people take daily vitamin supplements to ensure they get enough niacin and other essential nutrients, see also Coenzyme Nicotinamide Adenine Dinucleotide. 

Thiamine is particularly sensitive to thermal processing the published retention values range from 0 to 95% (Killeit, 1994). Wheat flour extruded with no added water suffered large thiamine losses, and increased barrel temperature decreased the vitamin only at the slowest feed rate used (250 g/min versus 500 and 750 g/min) (Andersson and Hedlund, 1990). In the same study, extrusion conditions did not affect the content of riboflavin (B2) or niacin ascorbic acid (C) decreased with higher temperatures at 10% moisture. Since enriched wheat flour is an important source of B vitamins in the United States, care must be taken to protect these vitamins. Relatively little is known about the stability of synthetic vitamins compared with natural sources, or the effects of added vitamins as opposed to endogenous nutrients. 

Niacin in mature cereal grains, particularly in com, is largely bound and is poorly available alkali treatment of the grain increases the percentage absorbed. Meat and fish have the scarce free form of niacin and niacinamide but contain high levels of NAD/ NADP, which are available as niacinamide after digestion (Prousky et al. 2011). Fortification of flour and cereal products adds up to 20 mg of the free form of niacin per serving to items such as breakfast cereals (Food and Nutrition Board 1998). 

Precision obtained for the samples in Table 19.2, expressed as relative standard deviations (RSD), ranges from 0.5% to 2.7%. Mean levels of niacin obtained for the commercial flour and cereal samples are higher than the expected values, but this is not surprising. Due to labelling requirements for fortified foods (Bender et al. 1998), such foods are often fortified in excess of the stated amounts. Results for the flour (RM 8437) and cereal (RM25C) reference... 

Table 19.2 Results of niacin determinations for food samples. Niacin determinations by LC-IDMS are compared to expected values for six grain-derived food materials. Expected levels for the commercial flour and cereal samples (Brands A, B, C, and D) are according to the package labelling, although it should be noted that actual vitamin levels of vitamin fortified foods are often higher than the stated amounts. The determined niacin levels for these samples, listed in the third column with their 95% confidence limits, are from 30% to 70% higher than the claimed levels. Determined niacin levels for the two reference materials (RM) are in agreement with the expected levels. Data are from Goldschmidt and Wolf (2007), with permission from the publisher.

LaCroix, D.E., Wolf, W.R., and Vanderslice, J.T., 1999. Determination of niacin in infant formula and wheat flour by anion-exchange liquid chromatography with solid phase extraction cleanup. Journal of AOAC International. 82 128-133. 

In some countries, nicotinic acid is added to white wheat flour and to other cereal products. The complex with menadione bisulfite, which shows the activity of niacin and vitamin K, has been used in animal nutrition. Nicotinamide in combination with ascorbic acid is used as a meat colour stabiliser, but has not found wider application in the meat industry (under anaerobic conditions, metmyoglobin in raw meat is reduced back to myoglobin by enzymes that contain NAD as a cofactor). 

Usually made from coarse bailey flour, produced by milling the de-huM, whole gram, with added rngrediems such 8S yeast, tricalaum phoS phate, salt, iron, niacin, and thiamin. 

Vitamins— Thiamin, riboflavin, and niacin are often added to white flour and breakfast cereals, and sometimes to white rice. Milling also removes much of the other B-complex vitamins present in whole grains. Vitamins A, C, and D are not always added to cereal products so, other sources of the vitamins should be consumed along with the cereal products. 

For this purpose, rice fortified to the same levels as enriched white wheat flour in the United States seemed appropriate. As distributed, each pound of the product contained 2 mg of thiamin, 16 mg of niacin, and 13 mg of iron. 

In 1940, the National Academy of Sciences-National Research Council appointed a Committee on Food and Nutrition (later called the Food and Nutrition Board) to develop a table of Recommended Daily Allowances for Specific Nutrients. This committee proposed the use of the term enriched and set up minimum and maximum limits for the enrichment of bread and flour with thiamin, riboflavin, niacin, and iron. With the support of the millers, enriched flour became available to the public and wtis used by the Army and Navy. 

Also see ADDITIVES CEREAL GRAINS, section headed "Enriched or Fortified Cereals" CORN, Table C-23 Com Products and Uses for Human Food FLOURS, section headed "Enrichment and Fortification of Flours" IRON, section headed "Sources of Iron" NIACIN, section headed "Sources of Niacin" NUTRIENTS REQUIREMENTS, ALLOWANCES. FUNCTIONS, SOURCES RIBOFLAVIN, section headed "Sources of Riboflavin" RICE, section headed "Nutritional Value" THIAMIN, section headed "Sources of Thiamin" and WHEAT, section headed "Enriched Flour.")... 

Type of Flour Calcium IroR TbioRiiR Ribofluvin Niacin... 

It may be seen from Table F-14 that the milling procedures used to make white flour result in a product containing much less calcium, iron, thiamin, riboflavin, and niacin than whole wheat flour. However, enrichment of white flour restores the iron, thiamin, riboflavin, and niacin to levels equaling or slightly exceeding those in whole wheat flour. The use of calcium monophosphate in self-rising flour constitutes calcium fortification because it raises the level of this mineral so that it greatly exceeds the calcium content of whole wheat flour. 

About 20% of the iron in the average U.S. diet comes from fortified products. Enrichment of flour (bread) and cereals with iron (along with thiamin, riboflavin, niacin, and with calcium enrichment optional), which was initiated in 1941, has been of special significance in improving the dietary level of iron in the United States. It is noteworthy that the major iron-enriched foods provide the following quantities of iron ... 

Enrichment The most common practice is to add the specified amounts of iron, thiamin, riboflavin, and niacin in chemically pure form. However, the restoration of iron and three vitamins replaces only a few of the two dozen or more essential nutrients that are removed in substantial amounts during the conversion of whole wheat kernels into semolina or flour. 

The U.S. Department of Agriculture reports that there are sufficient available food sources in the United States to provide an average consumption of 26 mg of niacin per person per day with 45% of the total contributed by meat, poultry, and fish, and 31% contributed by flour and cereal products. 

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