Phytic acids

Functional properties of canola protein products can be improved by succinylation (130,131). Controlled acetylation can reduce undesirable phenoHc constituents as well (132). However, antinutrients in canola and other vegetable protein products such as glucosinolates, phytic acid, and phenoHc compounds have severely limited food appHcations of these products. 

Phytic acid (9), although restricted to a more narrow range of food products, mainly grains, complexes a broader spectmm of minerals than does oxahc acid. Decreased availabiUty of P is probably the most widely recognized result of excessive iatakes of phytic acid, yet Ca, Cu, Zn, Fe, and Mn are also complexed and rendered unavailable by this compound (47—49). Phytic acid has also been reported to reduce the activity of a-amylase and to decrease the activity of both proteolytic and Hpolytic enzymes (50). 

Many plant substances possess antivitamin D activity but the mode of action and in most cases the identity remain unknown. Rachitogenic factors have been observed in yeast. Because of the metaboHc interrelationships that exist between vitamin D, Ca, and P, it is sometimes difficult to differentiate between chelators of mineral elements and tme antivitamins. One reported vitamin D antagonist in oats was later identified as phytic acid (72). 

Minor Constituents. All four oilseeds contain minor constituents that affect the use of the defatted seeds, especially in feeds and foods. Percentages of phytic acid [83-86-3] (3), for example, are soybean, 1.0—1.5 (30) cottonseed kernels, 2.2—3.8 (25) peanut kernels, 0.8 (25) and sunflower, 1.6-1.7 (31). 

Proteins and Meals. Nutritional properties of the oilseed protein meals and their derived products are deterrnined by the amino acid compositions, content of biologically active proteins, and various nonprotein constituents found in the defatted meals. Phytic acid (3), present as salts in all four meals, is beheved to interfere with dietary absorption of minerals such as 2inc, calcium, and iron (67) (see Food toxicants, naturally occurring Mineral nutrients). ... 

Heretofore, no economical method for preparing pure phytic acid was known. The classical method was to dissolve calcium phytate in an acid such as hydrochloric acid, and then add a solution of a copper salt, such as copper sulfate to precipitate copper phytate. The latter was suspended in water and treated with hydrogen sulfide, which formed insoluble copper sulfide and released phytic acid to the solution. After removing the copper sulfide by filtration, the filtrate was concentrated to yield phytic acid as a syrup. 

The phytic acid in the form of a calcium phytate press cake may however be contacted with a cation exchange resin to replace the calcium with sodium to yield phytate sodium. 

Preparation by hydrolysis of phytin isolated from maize steep water [Ca- and Mg-salts of phytic acid (inositol hexa(dihydrogen phosphate))] with diluted sulfuric acid or with water under pressure. 

URBANO G, LOPEZ-JURADO M, ARANDA P, VIDAL-VALVERDE C, TENORIO E, FORRES J (2000) The role of phytic acid in legumes antinutrient or beneficial function J Physiol Biochem. 56 283-94. 

Table 8.2. Properties of cements based on phytic acid Prosser et al, 1983)...

Phytic acid, 40 % PAA 50% Phytic acid, 40 % Cement liquid"... 

Copper(II) oxide and cobalt(II) hydroxide form cements with solutions of many multifunctional organic acids propanetricarboxylic acid, tartaric acid, malic acid, pyruvic acid, mellitic acid, gallic acid, tannic acid and phytic acid (Allen et al., 1984 Prosser et al., 1986). These have been used mainly in cement devices for the sustained release of copper and cobalt (Manston et al., 1985 Mansion Gleed, 1985). Little is known about... 

Graf, E. (1986). Chemistry and applications of phytic acid an overview. In Graf, E. (ed.) Phytic Acid, Chapter 1. Minneapolis Pilatus Press. 

An equally simple chemical study was carried out on phytic acid-aluminosilicate cements (Prosser et al., 1983). Phytic acid, myo-inositol hexakis(dihydrogen phosphate), is a naturally occurring substance found in seeds, and it is a stronger acid than phosphoric acid. Cements were prepared using aqueous solutions of phytic acid, concentrated to 50 wt%, and with 5 wt % zinc dissolved in the acid to moderate the rate of reaction with the glass powder. Discs of cement were prepared and these were... 

Phytic acid (inisitol hexakisphosphate) is the main storage form of phosphorus in plants. The phosphorus is not bioavailable to non-ruminants as they lack the enzymes to break it down. Novozyme has developed a commercial enzyme, phytase, that can be added to animal feed to release the phosphorus. No inorganic phosphorus needs to be added. This shift in the source of phosphorous has a large impact on the environmental footprint of pig farming. 

In addition, there is now epidemiological evidence that dietary antioxidants, such as vitamins A, C, D and E, phytic acid, and protease inhibitors can prevent carcinogenesis, including that of the gastrointestinal (GI) tract (Graf and Eaton, 1990 Block, 1991 Malone, 1991 Troll, 1991 Weisburger, 1991). 

Jariwalla, R.J., Sabin, R., Lawson, S., Bloch, D.A., Prender, M., Andrews, V. and Herman, Z.S. (1988). Effects of phytic acid (phytate) on the incidence and growth rate of tumours... 

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). 

Rounds, M.A. and Nielsen, S. S., Anion-exchange high-performance liquid chromatography with post-column detection for the analysis of phytic acid and other inositol phosphates, /. Chromatogr. A, 653, 148, 1993. 

Steveninck R.F.M. Van, Babare A., Fernando D.R., Steveninck M.E.Van. The binding of zinc, but not cadmium, by phytic acid in roots of crop plants. Plant Soil 1994 167 ... 

Engelman HM, Alekel DL, Hanson LN, Kanthasamy AG and Reddy MB. 2005. Blood lipid and oxidative stress responses to soy protein with isoflavones and phytic acid in postmenopausal women. Am J Clin Nutr 81 590-596. 

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