FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
TITLE OF THE INVENTION "OXIDATIVELY STABLE BIOASSIMILABLE MICROENCAPSULATED IRON "
APPLICANT
Indian Institute of Technology, Bombay of Dept. of Biosciences and Bio engineering , Powai, Mumbai-400076, Maharastra, India; Indian
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed

FIELD OF INVENTION
This invention relates to oxidatively stable, bioassimilable, microencapsulated iron. This invention particularly relates to a white coloured, oxidatively stable, bioassimilable hydrogen reduced iron powder microencapsulated in biodegradable stearic acid and soya phosphatidylcholine. These micro capsules are substantially free of trans-fats and sugars. This invention also relates to a process for preparing the above referenced microcapsules.
BACKGROUND OF THE INVENTION
Iron deficiency anemia is rampant in infants, children and women of child bearing age. In many developing countries, ferrous sulphate capsules as an additional iron supplement have had poor patient compliance. Fortification of food is an attractive strategy for improving the iron levels in the population. However, iron supplementation in food is hindered by its colour and undesirable metallic taste. There is a need for the development of technologies that can mask the colour, taste and other undesirable properties of iron by developing biodegradable, food grade material encapsulated iron for fortification.
Prior Art
US patents (US 7458765, 6033791, 5439535, 4929288 and 4029140) deal with the development of non-degradable hard coatings for wear resistant white iron alloys which are not suitable for fortification. They consist of using a laser beam with diamond coatings on ferrous substrates for white iron castings in pumps, or wear resistant carbides selected from silicon, manganese, chromium mixtures or development of white iron molding process using tellurium or

bismuth along with clay. None of these patents deal with food grade biodegradable materials and the processes and compositions described contain toxic elements not suitable for food fortification.
Patent US 6998143 claims a ferric fortification system using ferric ions and caseinates. It is made by dissolving a casein source in an aqueous liquid to provide a casein solution; adjusting the pH of the casein solution to about 5.4 to about 6.2; dissolving ferric sulfate in an aqueous liquid to provide a ferric solution; adjusting the pH of the ferric solution to about 5.4 to about 6.2; combining the ferric solution with the casein solution and adjusting the pH to about 5.4 to about 7.0; and collecting ferric-caseinate complex. Casein can form complexes with ferric salts, which lead to a lower bioavailability. It is restricted to the complexes formed with ferric salts and does not use other forms of pure iron powder in the form of hydrolytic or hydrogen reduced iron. Many individuals have allergic reactions to casein.
Patent US 6207204 claims a cereal grain kernel coated with a metal amino acid chelate, where the coating is comprised of a stabilizer like a hydrocolloid gum for example hydroxypropylcellulose and ethycellulose, and a metal amino acid chelate having a ligand to metal molar ratio from 1:1 to 4:1. The metal content ranges from 0.001% to 2% by weight. The iron chelate is in the form of ferrous bisglycinate or ferric trisglycinate. The patent is restricted in the content of iron and the specific iron chelates that may be used. It requires amino acids and additional hydrocolloid gums for stabilization. Further, it is suitable only for cereal kernel coatings.
Patent US 4931292 claims the development of complex chemically modified iron (III) phosphate compounds for food fortification such that they have low

water solubility and high acid dissolution. This is a new chemical moiety whose biological toxicity and degradation profiles are unknown.
US patent 6830761 describes microencapsulated iron granules in combination with an excipient which is an edible oil in hydrogenated form and optionally one or more bioavailable forms of an additional micronutrient. The coating for encapsulation is prepared from monoglycerides, diglycerides, ethylcellulose, hydrogenated soybean oil, acacia gum and their mixtures. The additional micronutrients are selected from zinc, vitamin A, iodine and ascorbic acid. The iron granules are upto 850 microns in diameter. The composition contains hydrogenated oils which contain trans fatty acids having undesirable health effects and whose long term use acts as risk factors for diabetes, cancer and cardiovascular diseases. The composition also requires the addition of ethylcellulose and acacia gum which can raise the viscosity of the supplement in food particularly fluids like milk.
US patent 7645470 describe iron fortified milk based flavored beverages with improved colour. The composition consists of a nutritional beverage comprising fat; milk protein representing from about 10% to 100% by weight of total protein; carbohydrate comprising from about 75% to 100% by weight of total carbohydrate of from about 0.1% to about 20% maltodextrin by weight of the nutritional beverage, the maltodextrin having a DE value of from about 2 to about 7, an iron-containing material, flavorant, and from about 0.02% to about 5% by weight of sodium hexametaphosphate. The iron containing material is iron sulfate. The patent does not deal with microencapsulated pure iron powder, in electrolytic or hydrogen reduced forms, which is white in colour. It contains additional agents like sodium hexametaphosphate, maltodextrin and is restricted in use for milk based flavored beverages. Sodium hexametaphosphate consumption in large quantities (cumulative) has

undesirable health effects and is not suitable on sodium restricted diets. Maltodextrin is derived from corn and needs to be avoided in cases of allergy.
Patent 5888563 describes the use of bilayer forming emulsifiers in nutritional compositions comprising divalent mineral salts to minimize off tastes and interactions with other dietary compounds. The iron sources are selected from ferrous fumarate and ferrous succinate and the iron source is preferably spread on the surface of a lecithin coated edible carrier such as sucrose. This is used in chocolate flavored edible mixes, especially chocolate flavored beverages, that are additionally fortified with other minerals and vitamins, like iodine, vitamin A, vitamin C, riboflavin, and folic acid. Phospholipids and bile salts are used as emulsifiers for coating on the surface of edible substrates like corn starch, potato starch, cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose. Preferred edible substrates are sugars, and especially combinations of sugar with a creamer and/or fat. The invention is restricted to ferrous fumarate and ferrous succinate as the sources of iron and does not deal with pure iron powder in the form of hydro lytic or hydrogen reduced iron. The process involved is of coating the phospholipids on the surface of a sugar base rather than the formation of self assembled solid lipid microparticles. The presence of starch, cellulose or sugars may be undesirable for diabetics and the invention is suitable only for flavored beverages like chocolate.
Patent 5670344 deals with chocolate-flavored beverage mixes that are fortified with highly bioavailable sources of iron such as ferrous fumarate and ferrous sulfate, but do not develop undesirable gray color when the beverage mix is reconstituted with water or milk, even when the water or milk has been boiled. The technology used is addition of edible acids such as citric or malic acid as buffering agents in the beverage mix so that the pH of the reconstituted chocolate beverage is about 6.5 or less. The patent does not deal with a

biodegradable microencapsulated white colored pure iron powder in the form of hydrolytic or hydrogen reduced iron. The addition of citric or malic acid and the low pH of the beverage is undesirable due to an increased incidence of cavities.
OBJECTS OF INVENTION
A major objective of this invention is to develop a biodegradable microencapsulated form of hydrogen reduced iron powder which is white in colour.
Another object is to provide a white powder or paste of iron that is suitable for food fortification.
Another object is to provide low density iron for fortification in milk and milk based products without any change of colour, taste or viscosity, even on heating of milk.
Yet another object is to provide nutritionally beneficial components like polyunsaturated fatty acids and phosphatidylcholine in the encapsulating material.
Another object is to additionally supplement other micronutrients and vitamins.
Advantages
The microencapsulated reduced iron of the present invention has the following advantages over prior art. - white in colour

- biodegradable, bioassimilable and stable
- suitable for fortification in milk and other food products without change in colour even on heating
- avoids harmful additives
- sugar free
- contains phosphatidylcholine which is beneficial for neurological functions -contains stearic acid which is a trans free, oxidatively stable, non-LDL cholesterol raising component that is beneficial as an alternative to transfatty acids
- contains polyunsaturated fatty acids which have several health benefits
- contains antioxidants which have beneficial health effects
BRIEF DESCRIPTION OF INVENTION
This invention relates to microencapsulated hydrogen reduced iron in stearic acid and soya phosphatidylcholine which is white in colour.
The composition is suitable for fortification of foods for administration in infants, children, pregnant women, and individuals with dietary restrictions like diabetics, gluten allergies, and those at cardiovascular risk and may be made available in the form of a paste or powder.
The composition can be directly added to foods without requiring any further preparation or processing prior to administration. When added to food, the composition does not adversely affect the taste or colour of the food. The encapsulation allows masking of the metallic tastes of iron and prevents the oxidation of iron even in liquid environments. The composition can be added to milk without any change in colour, taste, viscosity even on heating without the requirement of any addition stabilisers or flavorants.

The composition is also suitable for addition into powdered milk, puddings, cheese, cottage cheese, soymilk, lactose free milk, yoghurts, and other milk based products, and cereals, infant foods, purees of fruits, vegetables and meat.
The composition consists of reduced iron of up to 750 microns size, along with stearic acid, soya phosphatidylcholine, optionally with sodium taurocholate, and d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS).
The encapsulating material may contain only stearic acid and soya phosphatidylcholine sodium.
The encapsulating material may contain linseed oil as a source of polyunsaturated fatty acids.
The process of making the microencapsulated iron involved emulsion and homogenization techniques. One gram of stearic acid was heated at 80° C and 2 gm of reduced iron powder was added to the molten lipid (solution A). Soya phosphatidylcholine (500mg), preferably and optionally contains sodium taurocholate (1.88 gm) were dissolved in 10ml of water by homogenization and 5ml of 4% w/v solution of TPGS was added (solution B). Solution B was added to the hot solution A at 80C with continuous homogenization. Then this hot emulsion is added to the cold water(l :10v/v) at once and the dispersion was homogenised for another 5 minutes. The resultant mixture was centrifuged at 2500rpm for 10 minutes at 4°C to remove unencapsulated iron particles. The product was a white paste of microencapsulated iron particles which was further freeze dried to obtain a white powder.
The process may be carried out without TPGS and sodium taurocholate to 1 gm

of stearic acid and 750mg of soya phosphatidylcholine constitute the encapsulating composition.
The microencapsulated iron is white in colour and remains so even on storage for prolonged periods.
The microencapsulated iron does not get oxidized or leached when it is added to fluids.
The microencapsulated iron had iron contents ranging from 0.1 to greater than or equal to 8 wt%.
The microencapsulated iron floated in milk on addition and did not cause in change in colour or phase separation.
The microencapsulated iron was completely dissolved in milk and did not cause any change in colour or phase separation even on boiling the milk.
The microencapsulated iron shows acid dissolution which is improved in the presence of ascorbic acid, folic acid or other enhancers of iron absorption.
The microencapsulated iron could be used for fortification in doses of 4 to 24 mg iron /liter without any changes in the viscosity or optical properties of milk.
STATEMENT OF INVENTION
This invention relates to white coloured, oxidatively stable, bioassimilable, hydrogen reduced, food grade iron powder microencapsulated in biodegradable

stearic acid and soya phosphatidylcholine, substantially free of sugar and transfat.
This invention also includes a process for preparing oxidatively stable, bioassimilable trans-fat and sugar free microencapsulated hydrogen reduced food grade iron particles comprising the steps of:
(a) heating stearic acid to about 80°C and adding hydrogen reduced iron powder thereto forming solution A.
(b) dissolving soya phosphatidylcholine in water under homogenization, optiionally in the presence of sodium taurocholate and/or d-alpha-tocopheryl polyethylene glycol (TPGS) to form solution (B)
(c) Mixing solutions A and B under homogenization followed by addition of cold water to said mixture under continued homogenization
(d) Centrifuging said homogenized mixture of solutions and freeze drying the resultant microcapsules
The following examples illustrate the preparation of the microencapsulated iron for food fortification and its effects on addition to foods.
Example 1
Preparation of microencapsulated white iron
The process of making the microencapsulated iron involved emulsion and homogenization techniques. One gram of stearic acid was heated at 80° C and 2 gm of reduced iron powder was added to the molten lipid (solution A). Soya phosphatidylcholine (500mg), sodium taurocholate (1.88 gm) were dissolved in 10ml of water by homogenization and 5ml of 4% w/v solution of TPGS was added (solution B). Solution B was added to the hot solution A at 80C with continuous homogenization. Then this hot emulsion is added to the cold water(l:10v/v) at once and the dispersion was homogenised for another 5

minutes. The resultant mixture was centrifuged at 2500rpm for 10 minutes at 4°C to remove unencapsulated iron particles. The product was a white paste of microencapsulated iron particles which was further freeze dried to obtain a white powder.
Example 2
Preparation of microencapsulated iron without any bile salts One gram of stearic acid was heated at 80° C and 2 gm of reduced iron powder was added to the molten lipid (solution A). Soya phosphatidylcholine (750mg), were dissolved in 10ml of water by homogenization (solution C). Solution C was added to the hot solution A at 80C with continuous homogenization. Then this hot emulsion is added to the cold water( 1:1 Ov/v) at once and the dispersion was homogenised for another 5 minutes. The resultant mixture was centrifuged at 2500rpm for 10 minutes at 4°C to remove unencapsulated iron particles. The product was a white paste of microencapsulated iron particles which was further freeze dried to obtain a white powder.
Example 3
Preparation containing PUFA
900 mg of stearic acid was heated at 80° C and 2 gm of reduced iron powder was added to the molten lipid (solution A). Linseed oil (100 mg) was added to soya phosphatidylcholine (1 gm), dissolved in 10ml of water by homogenization (solution D). Solution D was added to the hot solution A at 80C with continuous homogenization. Then this hot emulsion is added to the cold water(l:10v/v) at once and the dispersion was homogenised for another 5 minutes. The resultant mixture was centrifuged at 2500rpm for 10 minutes at 4 C to remove unencapsulated iron particles. The product was a white paste of microencapsulated iron particles which was further freeze dried to obtain a white powder.

Example 4
Preparation using sonication or high pressures
The process of making the microencapsulated iron involved emulsion and homogenization techniques. One gram of stearic acid was heated at 80° C and 2 gm of reduced iron powder was added to the molten lipid (solution A). Soya phosphatidylcholine (500mg), sodium taurocholate (1.88 gm) were dissolved in 10ml of water by homogenization under high pressure for multiple passes and 5ml of 4% w/v solution of TPGS was added (solution B). Solution B was added to the hot solution A at 80C with continuous homogenization under high pressure for multiple passes. Then this hot emulsion is added to the cold water(l:10v/v) at once and the dispersion was homogenised under pressure under multiple passes. Alternately, the mixture is sonicated for 1-2 minutes. The resultant mixture was centrifuged at 2500rpm for 10 minutes at 4°C to remove unencapsulated iron particles. The product was a white paste of microencapsulated iron particles which was further freeze dried to obtain a white powder.
Example 5
Encapsulation
The microencapsulated iron prepared by homogenization resulted in
encapsulation of iron ranging from 0.1 wt% to > 8 wt%.
Example 6 Stability
The microencapsulated white iron can be stirred as a paste of microparticles or as a freeze dried powder. There is no phase separation or colour change on storage for a period of one month and can be added to water or aqueous based fluids without any oxidation or change in colour.

Example 7 Addition to milk
The microencapsulated iron was added as a paste or powder to milk. The dose added was 24 mg/liter. The powder floated in milk and was easily dissolved without any phase separation or colour change in milk. (Figure 3 &4)
Example 8 Viscosity
On addition of the microencapsulated iron to milk as a paste or powder in a dose of 2-24 mg/liter, the viscosity of milk was found to be unchanged and was a low value of 2-10 cP.
Example 9
Effect of boiling of milk
The microencapsulated iron was added as a paste or powder to milk. The dose added was 24 mg/liter. The powder floated in milk and was easily dissolved without any phase separation or colour change in milk. (Figure 5) The milk fortified with the microencapsulated iron was then heated and allowed to boil. There were no phase separations or changes in colour or texture of the milk after boiling.
Example 10 Dissolution
The dissolution of the microencapsulated iron was evaluated in an acid dissolution medium. Dissolution studies were done in 0.1 N HC1 with various amounts of microencapsulated iron powder.
BRIEF DESCRIPTION OF DRAWINGS

Figure 1: White coloured microencapsulated iron
Figure 2: Effect of one month storage on microencapsulated iron
Figure 3: Effect of addition of microencapsulated iron paste to milk at a dose of
24 mg/liter
Figure 4; Effect of addition of microencapsulated iron powder to milk at a dose
of 24 mg/liter
Figure 5: Effect of boiling milk to which microencapsulated iron has been
added at a dose of 24 mg/liter
Figure 6 Viscosity of the fortified milk after addition of microencapsulated iron
Figure 7 Dissolution of microencapsulated iron in acid medium (0.1 N HC1)
Obvious modifications and alterations known to person skilled in the art are within the scope and ambit of the appended claims.

WE CLAIM
1. White coloured, oxidatively stable, bioassimilable, hydrogen reduced, food grade iron powder microencapsulated in biodegradable stearic acid and soya phosphatidylcholine, substantially free of sugar and trans-fat.
2. Microencapsulated iron as claimed in claim 1 wherein the ratio of stearic acid to soya phosphatidylcholine is in the range of 4:3 to 2:1.
3. Microencapsulated iron as claimed in claims 1 & 2 wherein said particle contains polyunsaturated fatty acids like linseed oil in the ratio of 9:1 of stearic acid to linseed oil.
4. Microencapsulated iron as claimed in claims 1-3 containing upto 4% of antioxidants like d-alpha-tocopheryl polyethylene glycol 1000 succinate.
5. Microencapsulated iron as claimed in claims 1-4 containing optionally bile salts like sodium taurocholate.
6. Microencapsulated iron as claimed in claims 1-5 where the micro particles contain 0.1 to > 8 wt% iron.
7. Microencapsulated iron as claimed in claims 1-6 where the particles are in the form of a white paste or white freeze dried powder
8. Microencapsulated iron as claimed in claims 1-7 wherein 1 g of stearic acid and 750 mg of soya phosphatidylcholine constitute the encapsulating medium.

9. Micro encapsulated iron as claimed in claims 1-8 wherein the particle size of reduced iron is upto 750 microns.
10. Micro encapsulated iron as claimed in claims 1-9 optionally containing micro nutrients, vitamins and iodine.
11. Milk, milk products, solid and semi solid food articles fortified with microencapsulated iron as claimed in claims 1 to 10.
12. A process for preparing oxidatively stable, bioassimilable trans-fat and sugar free microencapsulated hydrogen reduced food grade iron particles comprising the steps of:

(a) heating stearic acid to about 80°C and adding hydrogen reduced iron powder thereto forming solution A.
(b) dissolving soya phosphatidylcholine in water under homogenization, optionally in the presence of sodium taurocholate,and or d-alpha-tocophenyl polyethylene glycol (TPGS) to form solution (B)
(c) Mixing solution A and B under homogenization followed by addition of cold water to said mixture under continued homogenization.
(d) Centrifuging said homogenized mixture of solutions and freeze drying the resultant microcapsules.

13. The process as claimed in claim 12 wherein linseed oil is added to solution B prior to homogenization.
14. White coloured, oxidatively stable bioassimilable transfat and sugar free microencapsulated hydrogen reduced food grade iron powder substantially as herein described.

15. A process for preparing oxidatively stable, bioassimilable microencapsulated iron substantially as herein described.