Yeast folates

Manufacturing processes can result in a substantial loss of the vitamin for example, during the milling of whole wheat to white flour, 75% of the folate is lost (B8). Bread was found to contain more folate than the flour fixim which it was made and this was due to the effect of the added yeast. Folate deficiency has been found to be relatively uncommon in Iran and this prompted Russell (R8) to measure the folate content of various Iranian breads since bread is the staple food in that country. They found village wholemeal bread to have a free folate concentration of 340 M.g/kg and leavened breads made... 

In historical terms, folates are among the most recently identified of the vitamins. Wills was the first to describe a form of anaemia associated with pregnancy and malnutrition which could be cured by yeast or liver extract (Wills, 1933 Wills et al, 1937). The active constituent of these dietary... 

Vitamins such as thiamin, biotin, and vitamin Bj2 are often added. Once again, the requirements of anaerobes are somewhat greater, and a more extensive range of vitamins that includes pantothenate, folate, and nicotinate is generally employed. In some cases, additions of low concentrations of peptones, yeast extract, casamino acids or rumen fluid may be used, though in higher concentrations, metabolic ambiguities may be introduced since these compounds may serve as additional carbon sources. 

Folates Yeast, liver, fresh green vegetables Nucleotide metabolism... 

Eolates are present in nearly all natural foods. Those with the highest folate content include yeast, liver and other organ meats, fresh green vegetables and some fresh fruits. The term folic acid arose from its first identification in leafy vegetables (e.g. spinach). 

The major sources of folate are green vegetables, citrus fruits, legumes, egg yolk, wheat germ, and yeast [417]. This vitamin can be added only in the form of pteroylmonoglutamic acid [402]. The multiplicity of forms, low stability, low concentration, and the complex extraction and detection techniques make the analysis of folate in food a difficult task. 

About 10-25%, i.e. 50-200 pg, of the daily dietary intake of folic acid in yeasts, liver, and green vegetables is absorbed via active and passive transport in the proximal jejunum. As humans do not have dihydropteroate synthetase, which synthesizes folic acid in bacteria, we require folic acid in the diet. Only small amounts of folate can be stored in the body and dietary deficiency for only a few days can result in symptomatic folate deficiency. 

HjPteGlu, yeast bovine pH 7.8 containing C18 (100 X tetrabutyl-ammo- 258 and 5-19% for total folate... 

Vitamin M Vitamin M is also called pteroylglutaminic add or folic acid. It was isolated from yeast extract by Wills in 1930. Its structure was described by Anger in 1946. Folic add is made up of pteridine + p-aminobenzoic add + glutamic add. There are several known derivatives, called folates, which are capable of mutual restructuring. The coenzyme tetrahydrofolic acid, which plays a role in many biochemical reactions, is formed with the help of Bi2. Around 50% of total body folate are stored in the liver. A folate-binding protein (FBP) is available for transport. Folate undergoes enterohepatic circulation. The release of folate from the liver cells is stimulated by alcohol, which increases urine excretion. Folate deficiency (e.g. in the case of alcohol abuse) is accompanied by the development of macrocytosis. 

Folic acid is obtained primarily from yeasts and leafy vegetables as well as animal liver. Animal cannot synthesize PABA nor attach glutamate residues to pteroic acid, thus, requiring folate intake in the diet. 

Chronic alcoholism is the major cause of folate deficiency in the United States. Alcoholics generally have poor diets — for example, one liter of whiskey per day. It is not dear if the alcohol induces metabolic defects that interfere with the metabolism and function of folate. Beer docs contain folate, as this product is brewed with yeast, an organism containing high levels tif the vitamin. Wine and hard liquors, on the other hand, contain little or no folate. The elderly may also be at risk for folate deficiency. It is thought that in the elderly the deficiency is due to poor diets rather than age-related defects in the absorption and utilization of folate. 

There may be a case for using folate with a long-chain glutamic acid residue such as that contained in yeast for absorption studies rather than a pteroylmonoglutamate. This should provide more useful information on the patient s ability to absorb food folates. However, in practice this is seldom done. 

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