Food fortification thiamin

Vitamin Bj or thiamine (Figure 19.21) is 3-(4-amino-2-methylpyrimidin-5-ylmethyl)-5-(2-hydroxyethyl)-4-methylthiazolium. It is isolated, synthesized, and used in food supplements and in food fortifications as a solid thiazolium salt in the form of thiamine hydrochloride or thiamine mononitrate [403]. 

The majority of breakfast cereals in the United States are fortified with PN, and additional PN is also added to infant formula products to ensure adequate vitamin Be supply to the infant. Gregory (100) reported an isocratic HPLC method for the determination of PN in breakfast cereals (Table 5). Other investigators attempted simultaneous determination of PN and other vitamins used in food fortification. Wehling and Wetzel used ion pair HPLC to separate pyridoxine, riboflavin and thiamine from each other after acid extraction of the vitamins from cereals (101). Using a dual fluorescence detector setup, pyridoxine and riboflavin were monitored by the first detector. After the column eluate had passed the first detector, an alkaline ferricyanide solution was introduced, resulting in the formation of a fluorescent thiochrome derivative of thiamine, which was detected by the second fluorescence detector. A similar method for simultaneous determination of pyridoxine and riboflavin in infant formula products has also been described (102). 

Most of the thiamine sold worldwide is used for dietary supplements. Primary market areas include the following appHcations addition to feed formulations, eg, poultry, pigs, catde, and fish (see Feeds and feed additives) fortification of refined foods, eg, flours, rice, and cereal products and incorporation into multivitamins. Small amounts are used in medicine to treat deficiency diseases and other conditions, in agriculture as an additive to ferti1i2ers (qv), and in foods as flavorings. Generally for dry formulations, the less soluble, nonhygroscopic nitrate is preferred. Only the hydrochloride can be used for intravenous purposes. Coated thiamine is used where flavor is a factor. 

The infrared technique has been described in numerous publications and recent reviews were published by Davies and Giangiacomo (2000), Ismail et al. (1997) and Wetzel (1998). Very few applications have been described for analysis of additives in food products. One interesting application is for controlling vitamin concentrations in vitamin premixes used for fortification of food products by attenuated total reflectance (ATR) accessory with Fourier transform infrared (FTIR) (Wojciechowski et al., 1998). Four vitamins were analysed - Bi (thiamin), B2 (riboflavin), B6 (vitamin B6 compounds) and Niacin (nicotinic acid) - in about 10 minutes. The partial least squares technique was used for calibration of the equipment. The precision of measurements was in the range 4-8%, similar to those obtained for the four vitamins by the reference HPLC method. 

Like thiamine, riboflavin is also used for the fortification of certain foods, such as wheat flour and breakfast cereals. Because of its yellow-orange colour, it is also used as a colouring for certain foods, especially cereal products, ice creams and sugar-coated pills. Hydroxyl groups of ribitol can be easily esterified by carboxylic acids. For example, riboflavin-2, 3, 4 5 -tetrabutyrate has been used as an antioxidant. 

By the beginning of World War II, cereal companies had started to enrich their products with thiamin, riboflavin, niacin, and iron. Enrichment means the restoration of some of the nutrients that are removed during the processing of a food. Later, in about 1955, fortification of cereals was started. Fortification means the addition of certain nutrients to foods in order to provide higher levels of such nutrients than are normally present in the natural, unprocessed foods. 

The enrichment of salt with iodine, the fortification of milk with vitamin D, and the start of the thiamin, riboflavin, niacin, and iron, grain enrichment program in 1941, have played a significant role in the practical elimination of the following deficiency diseases simple goiter, rickets, beriberi, ariboflavi-nosis, pellagra and simple iron-deficiency anemia. The average American receives approximately 40% of his thiamin, 25% of his iron, 20% of his niacin and 15% of his riboflavin from enriched foods. 

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.")... 

In addition to food sources, synthetic thiamin is also available mostly as thiamin hydrochloride, although thiamin mononitrate is often used for the thiamin fortification of cereal products that have to be cooked. 

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