Solubility phytic acid

Within the gut, oxidative damage may be prevented by phytic acid, obtained from cereals and vegetables (Graf et al., 1987), and by soluble non-starch polysaccharides like pectin (Kohen et al., 1993). The use of antioxidant vitamins in the treatment of inflammatory bowel disease has also been su ested (Evans et al., 1990). 

Figure 3- Effect of phytic acid on the solubility of 10 mM Ca + in 100 mM HEPES pH 7 4. (Reproduced with permission from Ref. 26. Copyright 1984 J. Nutr., American Institute of Nutrition.)...

In conclusion, phytic acid forms soluble complexes with Ca2+ at intestinal pH under a variety of conditions and fails to inhibit Ca2 bioavailability to mice in our experimental system. Despite the hazard in direct extrapolation of results obtained with animals kept on a well-defined dietary regimen to humans consuming a complex diet, many elements of which affect Ca2+ bioavailability, our data demonstrate the need for a reevaluation of the putative antinutritional properties of dietary phytate. Our further contention that adequate levels of dietary phytate may actually be beneficial due to its food preserving properties and its protection against colonic cancer will warrant a prospective epidemiological human study designed to assess the longterm effects of dietary phytate on mineral bioavailability and inflammatory bowel diseases. 

HV057 Sasatamoinen, M., S. Plaami, J. Kumpulainen, and O. Rantanen. Concentrations of water soluble and in- HV068 soluble beta-glucan and phytic acid in 6 row and 2-row barley. Cereal Res Commun 1991 19(4) 391-397. 

Phytase (Aspergillus niger var.) Produced as an off white to brown powder or as a tan to dark brown liquid by controlled fermentation using Aspergillus niger var. Soluble in water, but practically insoluble in alcohol, in chloroform, and in ether. Major active principles (1) 3-phytase and (2) acid phosphatase. Typical applications used in the production of soy protein isolate and in the removal of phytic acid from plant materials. 

The ash content of soybeans is relatively high, close to 5 percent. The ash and major mineral levels in soybeans are listed in Table 5-7. Potassium and phosphorus are the elements present in greatest abundance. About 70 to 80 percent of the phosphorus in soybeans is present in the form of phytic acid, the phosphoric acid ester of inositol (Figure 5-5). Phytin is the calcium-magnesium-potassium salt of inositol hexaphosphoric acid or phytic acid. The phytates are important because of their effect on protein solubility and because they may interfere with absorption of calcium from the diet. Phytic acid is present in many foods of plant origin. 

Multiple carboxylic acid compounds such as citric acid, ethylenediaminetetraa-cetic acid (EDTA), and phosphoric acid derivatives (polyphosphates and phytic acid) are commonly used in extending the shelf life of lipid-containing foods because of their metal chelating properties. Typically these chelators are water soluble, but citric acid exhibits solubility in lipids, which allows it to inactivate metals... 

A method is being developed to transform actinide ions in the near surface environment to less soluble, less reactive, thermodynamically stable phosphate minerals phases through application of organophosphorus complexants. These complexants decompose slowly, releasing phosphate to promote the formation of stable phosphate mineral phases, particularly with the more soluble trivalent, pentavalent, and hexavalent actinide ions. The complexant of choice, myo-inositol(hexakisphosphoric acid) or phytic acid, is a natural product widely used as a nutritional supplement. We have determined that phytic acid decomposes slowly in the absence of microbiological effects, that crystalline phosphate minerals are formed as a consequence of its decomposition, and that the formation of actinide (lanthanide) phosphates reduces the solubility of trivalent and hexavalent metal ions under environmental conditions. 

We have shown that phytic acid readily hydrolyzes to produce phosphate with a projected lifetime of 100-150 years in the absence of microbiological effects, that actinide-phytate compounds are insoluble, and that europium and uranyl phytates are converted to phosphates within a month at 85 °C. Thorium solubility, on the other hand, is controlled by hydroxide or oxide species. Furthermore, the solubilities of radiotracer europium and uranyl are reduced by phosphate dosing of a simulated groundwater solution, even in the presence of citric acid. In the same systems, neptunium(V) solubility is only affected by 0.01 M phosphate at pH greater than 7. The results of these tracer-scale immobilization experiments indicate that phosphate mineral formation from representative deposits is under thermodynamic control. 

Monoferric phytate is the major fraction of iron in wheat bran, and is a highly bioavailable form of dietary iron in contrast to insoluble di- or tetra-ferric phytate. Monoferric phytate equilibrates with the miscible nonheme iron pool of a meal in extrinsic label iron absorption tests. Whole wheat bran depressed absorption by humans of nonheme iron in a meal. Dephytinized wheat bran also inhibited nonheme iron absorption by humans and the inhibition could not be clearly attributed to either the insoluble or soluble fractions of the dephytinized bran. Adult men who consumed 36 g of wheat bran per day had positive iron balances. Iron balance was not increased when dephytinized bran was consumed. The form of ferric phytate must be known to properly explain the effect of phytic acid on iron absorption. The overall meal composition must be considered to evaluate the effect of wheat bran on iron nutrition of humans. 

In conclusion, the insoluble fraction, which is by far the main part of cereal dietary fiber, does not bind measurable amounts of ash after digestion with proteolytic and amylolytic enzymes under conditions similar to those in the human gastrointestinal tract. All the binding capacity seems to be due to the small soluble fraction in which the polysaccharides but also most of the phytic acid is recovered. 

Phytic acid (Figure 4.3) is the hexaphosphoric ester of me o-inositol. The affinity of ferric iron for phosphoric anions, already described in connection with the ferric casse mechanism, is responsible for calcium phytate s effectiveness in eliminating iron from red wines. Under these conditions, phytic acid produces a mixed calcium-iron salt, known as Calciphos, with the following composition Ca, 20%, P, 14% and Fe +, 2%. This mixed salt is not very soluble in water and easily precipitates, thus eliminating the excess ferric iron. Phytic acid is very widespread in plants. It acts as a phosphorus reserve, located in the seed coat, i.e. in wheat, rice and corn bran. Wheat bran may be used directly to eliminate iron from wine. 

Essential nutrient elements snch as Cu, Fe and Mn can be successfully incorporated into slowly soluble phosphate glass pellets, and fed to ruminant animals (Section 12.9). The glass pellet stays lodged in the rumen for several months where it supplies the nutrient elements [12]. Phospholipids are incorporated in some formnlations to improve animal metabolism. Phosphorus compounds are sometimes added to commercial prodncts for anti-microbial action or to increase their stability. Grains and seeds generally contain more P than hays and grasses, but in the former case much is present as phytic acid salts which are not easily nutritionally available. In some cases appropriate enzymes can be added to rectify this. 

Fig. 6.20A-F. Changes in various phosphate components in the roots (a), shoots (x) and non-axial parts —NAP ( ) of germinated oat seedlings. (A) Fresh weight, (B) Total phosphate, (C) Acid soluble phosphate. In the NAP this is comprised mainly of phytic acid, and in the shoot and root of inorganic phosphate and some acid soluble organic phosphate (but no phytic acid), (D) Nucleic acid phosphate, (E) Lipid phosphate, (F) Protein phosphate. Based on Hall and Hodges, 1966 [58]...

The addition of phytic acid to white flour markedly reduced the absorption of these minerals in short-term studies. With prolonged ingestion, the body can adapt to a high phytate intake apparently as a result of the action of enzymes which release the phosphate from soluble phytates. Phytases may be derived from the food, the digestive secretions or the intestinal bacteria. 

The recommended daily dietary doses of copper are 0.4-0.7 mg for children under 1 year, 0.7-2.0 mg for children aged 1 to 10 years, 1.5-2.5 mg for adolescents and 1.5-3.0 mg for adults. Resorption of copper and its retention in the body depend on the chemical form in which this element is present in the diet. Experiments on laboratory animals have shown a higher utilisation of copper in the form of neutral and anionic complexes contained in plant material than in the form of copper sulfate. Availability of copper increases the presence of proteins and amino acids in the diet. Also, carboxylic and hydroxycarboxylic acids stimulate resorption of copper. In contrast, higher doses of ascorbic acid, fructose, molybdenum, sulfur compounds and zinc significantly reduce the resorption of copper. Ascorbic acid reduces cupric compounds to slightly soluble cuprous compounds. The effect of phytic acid and dietary fibre on copper resorption is, in comparison with the effect of these components in zinc, less pronounced. 

Phytic acid R 0 I 0. -0 II y Y R R- -P. R, .L J-, HO OH V V R.O R Forms complexes with Ca, Fe, Mn, Zn and lower their bioavailability but also discussed to be cancer preventing Noncowdent interactions with proteins Forms insoluble electrostatic complexes with globulins and change their IP to low pH Seed dehuUing Pre-extraction at minimal protein solubility pH wdues Use of high ionic strenghts for protein isolation Ultrafiltration Phytase treatment... 

The aleurone layer differentiates from the rest of the starchy endosperm approximately 2 weeks after pollination. There is clear evidence that aleurone cells synthesize starch granules after fertilization however, the starch granules disappear and the cell walls thicken as the grain matures. The cytoplasm of aleurone cells contains phytic acid bodies, protein bodies, and spherosomes or fat depots. The aleurone ceU walls contain soluble and insoluble dietary fiber, phenolics such as ferulic acid, ara-binoxylans, and P-glucans that fluoresce when viewed under a microscope equipped with ultraviolet light. 

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