2.  Phytic acid is used widely as a food
additive in Japan.
 It is a yellow color liquid that
decomposes on heating.

3.  Empirical formula: C6H18O24P6
 Molecular weight:660.08
 physical appearance: Yellow colored
liquid
 Solubility: Miscible with water, 95% ethyl
alcohol, glycerol.
 Toxicity: Oral rat LD50: >90 ml/kg.
 Stability: Stable under ordinary
conditions.

4.  At low pH it precipitates iron
quantitatively
 At higher pH it forms insoluble complexes
with all other polyvalent cations.
 Some of the important physiological
function-of phytic acid include storage
of phosphorus, high-energy phosphate
groups, am; cations, and protection of
seeds against oxidative damage during
storage.

5.  The antioxidant functions of phytic acid have been
described by Graf and Eaton
 Phytic acid has a relatively high binding affinity for iron and
is a potent inhibitor of iron-mediated hydroxyl radical
formation.
 In the absence of phytate, Fe + is completely insoluble at
neutral or higher pH due to the formation of large
polynuclear iron hydroxide complexes.
 High concentrations of phytic acid solubilize iron in the form
of Fe(III) 1-phytate, whereas low concentration precipitate
iron as Fe(III)3- and Fe(III)4-phytate complexes.
 Chelating of iron by phytic acid prevents the formation of
polynuclear aggregates even at iron concentrations as low
as 6 nM.
 The six coordination sites of trivalent iron are occupied by
water and hydroxide ions in aqueous solutions.

6.  Most chelating agent displace five of these ligands and
form a pentadentate chelate with H2O occupying the
sixth coordination site.
 Phytic acid, however, is unique in occupying six
coordination sites and displacing all of the coordination
water in the Fe(III)complex.
 Iron-catalyzed formation of hydroxyl radical requires the
availability of at least one reactive iron coordination site
as well as iron solubility.
 Phytic acid preserves the solubility and makes the metal
totally enactive.
 In molar phytate-to-iron ratios of 0.25 and above, the
supcroxidc-driven generation c: hydroxyl radical is
completely blocked.

7.  Phytic acid appears to be one of the most effective agents
for the inhibition of iron-mediated lipid oxidation in foot
products.
 In meat products, it presumably removes myoglobin-derived
iron froivi negatively charged phospholipids and prevents
their autoxidation and off-flavor formation.
 Phytic acid substantially inhibits oxygen uptake,
malondialdehyde formation, and warmed-over flavor
development in cooked minced chicken breasts stored in
sealed oxygen-impermeable containers at 4°C.
 In a soybean oil-in-water emulsion system, the oxidation was
significantly decreased by the addition of 1M phytic acid.
 Phytic acid also significantly reduces the iron-catalyzed
oxidation and partially inhibits the copper-mediated
oxidation of ascorbic acid in model systems

8.  Phospholipids or phosphatides occur in all living organisms
and make up l-2% of many crude oils and animal fats.
 The term lecithin was initially used for crude fractions of
phospholipids obtained from vegetable oils or fats.
 At present it is used to refer to phosphatidylcholine (l,2-
diacylglycero-3-phosphorylcholinc).
 It is also used to describe soybean lecithin, which is
composed of soybean-phosphatides and soybean oil.
 Chemically, phosphatidylcholine consists of a glyceride in
which two of the hydroxyl groups are esterified with fatty
acids and the third is verified with a phosphoric acid that
in turn is bound to a molecule of choline. In
phosphatidylethanolamine, the choline is replaced by
ethanolamine.
 The commercial source of lecithin is mainly soybeans.

10.  Some of the parameters that characterize commercial
lecithin are acetone-insoluble matter, acid value,
moisture content, hexane-insoluble matter, color,
consistency, and clarity.
 Commercial lecithin insists of about 66% phospholipids, the
other major components being the glycerides.
 Lecithin is classified as plastic or fluid according to its viscosity.
 Each of these is further classified into natural, bleached, or
unbleached grades based on color.
 Only the unbleached grades are permitted as food additives.
 Commercial lecithin can also be produced as a powder by
alcohol or acetone extractions.
 It is soluble in oils and is hydrated in water with the formation
of an emulsion.

11.  The phospholipids function synergistically with primary
antioxidants, especially the tocopherols, in stabilizing various
fats and oils.
 Lecithin also functions as a carrier for antioxidants such as PG
in commercial mixtures.
 Commercial mixtures containing lecithin, a-tocopherol, and
ascorblypalmitate or ascorbic acid are available.
 In such mixtures, ascorbic acid regenerates tocopherol
mediated by lecithin.
 However, the mechanism is not understood.
 The various applications of the synergistic mixtures have been
described here under the food applications of toeopherols.

12.  Thank you