Niacin riboflavin

Niacin, riboflavin, pantothenic acid and vitamin B6 contents are greatly increased in tempeh during fermentation, whereas thiamin exhibits no significant change. H. oligosporus appears to have a great synthetic capacity for niacin, riboflavin, pantothenic acid, and vitamin B, but not for thiamin. 

Increase in vitamins, such as niacin, riboflavin pantothenic acid, Vitamin Be and Vitamin B12, is of great nutritional significance, especially where fortifying foods with synthetic vitamins is not practiced. 

Vitamins are chemically unrelated organic compounds that cannot be synthesized by humans and, therefore, must must be supplied by the diet. Nine vitamins (folic acid, cobalamin, ascorbic acid, pyridoxine, thiamine, niacin, riboflavin, biotin, and pantothenic acid) are classified as water-soluble, whereas four vitamins (vitamins A, D, K, and E) are termed fat-soluble (Figure 28.1). Vitamins are required to perform specific cellular functions, for example, many of the water-soluble vitamins are precursors of coenzymes for the enzymes of intermediary metabolism. In contrast to the water-soluble vitamins, only one fat soluble vitamin (vitamin K) has a coenzyme function. These vitamins are released, absorbed, and transported with the fat of the diet. They are not readily excreted in the urine, and significant quantities are stored in Die liver and adipose tissue. In fact, consumption of vitamins A and D in exoess of the recommended dietary allowances can lead to accumulation of toxic quantities of these compounds. 

A standard reference material for infant formula has also been certified for vitamin C, riboflavin, niacin, and pyridoxine (197). Another recent study (198) indicated that off-the-shelf wheat germ is suitable for use as a secondary reference material for thiamine and niacin riboflavin was also evaluated but found to be somewhat unstable over time. Powdered orange drink was deemed suitable as a secondary reference material for vitamin C. 

A good source of niacin, riboflavin, other B vitamins, iron, and calcium... 

High in niacin, riboflavin, and other B complex vitamins... 

Niacin, riboflavin, and lipoic acid give rise to coenzymes that participate in redox reactions. Niacin and riboflavin are essential in the human diet, whereas lipoic acid may be synthesized within the human organism. Lipoic acid is a required growth factor in many microorganisms and protozoa. It reacts covalently with the e-amino groups of apoenzymes to give the active holoenzymes ... 

The vitamin content (Table 1.9) is also interesting, because QS have high levels of vitamin B6 and total folate, whose amounts in 100 g can cover the requirements of children and adults. The riboflavin content in 100 g contributes 80% of the daily needs of children and 40% of those of adults (National Academy of Sciences, 2004). The niacin content does not cover the daily needs, but is beneficial in the diet. Thiamin values in quinoa are lower than those in oat or barley, but those of niacin, riboflavin, vitamin B6, and total folate are higher (Ranhotra et al., 1993 USDA, 2005). 

Almost all the activated carriers that act as coenzymes are derived from xnta-mins. Vitamins are organic molecules that are needed in small amounts in the diets of some higher animals. Table 15.3 lists the vitamins that act as coenzymes (Figure 15.17). This series of vitamins is known as the vitamin B group. Note that, in all cases, the vitamin must be modified before it can serve its function. We have already touched on the roles of niacin, riboflavin, and pantothenate. We will see these three and the other B vitamins many times in our study of biochemistry. 

Under aerobic conditions pyruvate is converted to acetyl CoA. The coenzymes NAD+, FAD, thiamine pyrophosphate, and coenzyme A are required by the pyruvate dehydrogenase complex for the conversion of pyruvate to acetyl CoA. These coenzymes are synthesized from the vitamins niacin, riboflavin, thiamine, and pantothenic acid, respectively. If the vitamins are not available, the coenzymes will not be available and pyruvate cannot be converted to acetyl CoA. Because the complete oxidation of the acetyl group of acetyl CoA produces the vast majority of the ATP for the body, ATP production would be severely inhibited by a deficiency of any of these vitamins. 

Ans. In order to accomplish these operations, the protein portion of an enzyme lacking catalytic properties, called an apoenyme, combines transiently with specialized small molecules called cofactors or coenzymes to form the catalytic holoenzyme. Cofactors are ions such as K+, Mg +, or Zn +. Vitamins such as nicotinic acid (niacin), riboflavin, thiamin, and pyridoxine (B ), serve as coenzymes in enzymatic redox, decarboxylation, and group transfer reactions. 

Rosenkrantz (1957) has published a review of the spectra of vitamins, hormones, and coenzymes in the solid state. Among the spectra of vitamins were those of vitamin A and its acetate, vitamin D2, a-tocopherol, menadione (the common substitute for vitamin K), thiamine hydrochloride, nicotinamide, niacin, riboflavin. 

Many people are poorly nourished because of (1) lack of interest in nutrition, (2) inadequate information about the role of foods, and (3) economic deprivation. In cultures where dietary patterns are simple and based on a limited number of commodities, one is able to identify which food could be a carrier for an enrichment program. Traditionally, staples such as wheat, rice, and com have served as vehicles for niacin riboflavin, thiamin, iron, and calcium. Milk has been as reliable a carrier of vitamin D, as table salt has been a carrier of iodine. Also, water Is employed as a carrier for fluorine. 

Skurray, G., A rapid method for selectively determining small amounts of niacin, riboflavin and thiamine in foods, Food Chem., 7, 77-80, 1981. 

Animals also depend on plants for essential organic molecules that they are unable to make. We call some of these molecules vitamins. Several vitamins, including niacin, riboflavin, pyridoxine, and biotin, are key players in catabolic and anabolic metabolism, and deficiencies in these vitamins have severe effects. Also, animals are incapable of synthesizing polyunsaturated fatty acids (fatty acids with more than one double bond). Polyunsaturated fatty acids are essential components of membrane lipids and must be obtained in the diet. So, the next time you have a salad, pay a tribute to photosynthesis. 

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