MXPA01008818A - Iron fortification system - Google Patents

Abstract

An iron-protein hydrolysate complex which may be used to fortifyfoods and beverages with iron. The complex is formed of ferrous ions chelated to partially hydrolyzed egg white protein. The hydrolyzed egg white protein has a molecular weight in the range of about 500 to about 10,000. The complexes are sufficiently stable as to be suitable for use in sterilized products, such as retorted products. Moreover, despite the stability, the iron in the complexes has substantially the same bioavailability as ferrous sulfate.

Description

IRON FORTIFICATION SYSTEM Description Field of the Invention This invention relates to an iron fortification system that can be based on egg white protein hydrolysates and what can be used in foods and beverages. The invention also relates to a method for preparing the system and fortifying foods and beverages with iron.

Background of the Invention Iron is an essential trace element in human and animal nutrition. It is a component of heme in hemoglobin and myoglobin, cytochromes and several enzymes. The main role of iron is its participation in the transport, storage and use of oxygen. Inadequate iron is a direct cause of the high incidence of anemia, especially among children, adolescents and women. The need for an adequate iron is one that extends to the entire life of the human being.

However, the body does not produce iron and is totally dependent on an external supply of iron; nutritious or supplementary. The recommended daily dose for iron intake is usually about 10 mg per day. However, the amount needed is dependent on age and sex. Children, women up to the time of menopause, and pregnant and lactating women have higher iron requirements.

Therefore, iron deficiency is essentially a nutritional problem; a nutritional problem that is not only common in developing countries. The problem is handled promptly by consuming foods that naturally provide adequate iron, but this is not always possible in disadvantaged societies. Also, many foods normally consumed in developed countries are poor in iron.

To provide a source of iron, many foods and drinks are supplemented with iron. Usually the source of iron used in the addition of a supplement is a soluble ferric salt such as ferric sulfate, ferric lactate, ferric gluconate, ferric fumarate, ferric citrate, choline citrate ferric, and ferric ammonium citrate. Ferric sulfate is especially common due to its good bioavailability. Unfortunately, ferric supplementation and especially ferric sulfate supplementation have pernicious effects. In particular, iron often causes discoloration and loss of flavors due to its ability to interact with polyphenols and lipids and promote destructive reactions of free radicals. This is especially the case at high temperatures and in the presence of oxygen and light.

For example, the addition of a soluble ferric source to chocolate milk powder causes the beverage to turn dark gray when reconstituted with water or milk. It is believed that this is due to the interaction between iron and iron-sensitive ingredients, such as polyphenols. Furthermore, the addition of soluble ferric sources in milk, cereals, other fat-containing products, mainly products with a high level of unsaturated fatty acids, causes the flavor to change due to the oxidation of lipids. Oxidation of lipids not only affects the organoleptic properties of food and beverages, but also undesirably affects the nutritional quality of these products. These interactions can also be reinforced during heat treatment, such as pasteurization or sterilization. In addition, the pH of some iron salt systems may not be compatible with other ingredients or may affect the taste. Also, from a technical point of view, soluble iron salts can cause corrosion of processing equipment.

Unfortunately, non-soluble or slightly soluble ferric sources such as elemental iron, ferric pyrophosphate, etc., are not sufficiently bioavailable. Therefore, while these may cause few or no problems of discoloration and loss of flavor, they are poorly absorbed by the body.

To deal with these problems, there have been several attempts to encapsulate or make compounds from the soluble ferric sources in a way that reduces their reactivity but maintains their bioavailability.

However the attempts have not been completely successful.

An example of encapsulated ferric source is described in U.S. Patent 3,992,555 wherein the iron is coated with an edible, metabolizable fat having a melting point between about 38 ° C and about 121 ° C. Hydrogenated and refined vegetable oils, and particularly the distilled monoglycerides of fully hydrogenated cottonseed oil, are described as being convenient. Although this iron encapsulation results in approximately 20% reduction in bioavailability, this is described as being acceptable as long as the used iron source has sufficiently good bioavailability. However, the primary problem is that, if the food must go through any form of rough processing, the capsule is destroyed. Therefore encapsulated iron can not be used in products that need to be retorted or subjected to other forms of rough treatment.

An early example of a ferric complex is described in U.S. Patent No. 505,986. This complex is a preparation of ferric albumin. The albumin is in intact form but coagulated by heat. The complex recovers as a precipitate. However, when these ferric albumin complexes are used in beverages, discoloration and oxidation occurs. For example, chocolate drinks fortified with ferric albumin complexes turn a gray color.

More recent examples of ferric complexes are described in U.S. Patent 4,172,072 wherein iron in ferric form is complexed with hydrolyzed casein or hydrolyzed liver powder. Several other hydrolyzed proteins are also mentioned as possible binders. The complexes are collected as insoluble precipitates. Unfortunately iron in complexes is unlikely to have an acceptable bioavailability.

Another example of an iron complex is described in WO 98/48648. This document describes iron (II) compounds gelatinized with amino acids or oligopeptides with two to four amino acids.

Examples of additional ferric complexes are described in U.S. Patent 4,172,072 wherein the iron is made in complex form with substantially completely hydrolyzed collagen. Several other fully hydrolyzed proteins are also mentioned as possible binders. However, the complexes are described as stable under acidic conditions and, because the conditions in the intestine are acidic, the iron in the complexes is unlikely to have an acceptable bioavailability. Also, the complexes are not strong enough to prevent discoloration and oxidation of the lipid.

Examples of additional ferric complexes are disclosed in U.S. Patent 4,216,144 wherein the iron ferric form is made in complex form with hydrolyzed protein; especially the soy protein. The bioavailability of iron in complexes is described as better than ferric sulfate. However, when ferric soy hydrolyzate complexes are used in beverages, discoloration and oxidation occurs. For example, chocolate drinks fortified with soy ferric hydrolyzate complexes turn a gray color.

Other examples of ferric complexes are described in Japanese patent applications 2-083333 and 2-083400. In these applications, ferric caseinate complexes are used to treat anemia. However, these complexes are not convenient to use to fortify foods and drinks because they are not stable enough. Also, these complexes are in the coagulated form and it is difficult to disperse them.

It is therefore an object of the invention to provide an iron fortification system that is relatively stable but where the iron is relatively bioavailable.

The invention Accordingly, in one aspect, this invention provides an iron protein hydrolyzate complex comprising gelatinized iron ions of partially hydrolyzed egg white protein having a molecular weight in the range of about 500 to about 50,000. .

It is surprisingly discovered that the complexes formed of ferric iron and partially hydrolyzed egg white protein are very stable. In fact, the complexes are sufficiently stable to be suitable for use in retorted products containing lipids and polyphenols. However, despite the stability, iron in the complexes has substantially the same bioavailability as ferric sulfate; which is remarkably good.

Preferably, the partially hydrolyzed egg white protein has a molecular weight in the range of about 2'000 to about 6'000.

In another aspect, this invention provides an iron protein hydrolyzate complex comprising gelatinized iron ions of the egg white protein which is partially hydrolyzed using a microbial protease.

Preferably, the microbial protease is a fungin protease obtained from Aspergillus oryzae and contains both endo-peptidase and exo-peptidase.

In a further aspect, this invention provides an iron protein hydrolyzate complex comprising gelatinized iron ions of the partially hydrolyzed egg white protein; the complex contains about 1% to about 2% or about 4.5% to about 10% dry weight of ferric ions.

The complexes are preferably stable at a neutral pH but dissociate at a pH below about 3.

In still yet another aspect, this invention provides a sterile liquid beverage containing stable lipids and a stable iron fortification system, the iron fortification system comprising an iron protein hydrolyzate comprising gelatinized iron ions of the clear protein. of partially hydrolyzed egg. The drink can be a beverage that contains chocolate.

In yet another aspect, this invention provides a sterilized liquid beverage containing polyphenols and a stable iron fortification system, the iron fortification system comprising an iron protein hydrolyzate comprising gelatinized iron ions of the egg white protein partially hydrolyzed The drink can be a tea drink.

The drinks can be sterilized by retorting or pasteurization at a very high temperature.

The invention also provides a beverage powder containing lipids and a stable iron fortification system, the ferric iron fortification system comprising a hydrolyzed iron protein complex comprising gelatinized iron ions of the partially hydrolyzed egg white protein . The powder of the drink may contain chocolate.

In a further aspect, this invention provides a process for preparing an iron fortification system, the process comprising: hydrolyzing enzymatically, preferably under acidic conditions, using a microbial protease, preferably an acid fungic, to provide a hydrolyzed egg white protein; adding a ferric source to the partially hydrolyzed egg protein under acidic conditions; and raise the pH to 6.5 to 7.5 to form a ferric hydrolyzed egg white protein complex as the iron fortification system.

The partially hydrolyzed egg white protein can be subjected to additional steps of hydrolysis before the addition of the iron source. Preferably the protease fungina is obtained from Aspergillus oryzae and contains both endo-peptidase and exo-peptidase.

The process may also include the additional step of drying the ferric hydrolyzed egg white protein complex to a powder form.

Detailed description of preferable representations Exemplary embodiments of the invention are now described by way of example only.

This invention is based on the discovery that the partially hydrolyzed egg white protein is capable of forming strongly complexes with ferric ions and still provide the iron in a bioavailable form. The resulting ferric complexes have a reduced ability to cause pernicious effects such as lipid oxidation, color degradation, and vitamin C degradation. This makes iron complexes an ideal vehicle for fortifying foods and beverages; especially the foods and drinks that are intended to improve nutritional status.

The ferric source that can be used in the ferric complexes can be any ferric salt of food grade, such as ferric sulfate, ferrous chloride, ferric nitrate, ferric citrate, ferric lactate, or ferric fumarate, or mixtures thereof. However, the preferred ferric source is ferric sulfate. The ferric source is preferably provided in the form of a ferric solution.

Ferric complexes are prepared by preparing a partially hydrolyzed egg white protein, adding the ferric source under acidic conditions, and then neutralizing.

The partially hydrolyzed egg white protein should be such that the molecular weight of the protein fragments is in the range of about 500 to about 10000; preferably about 2000 to about 6000. It is found that the ferric complexes that are prepared from the intact egg white protein or the extensively hydrolyzed egg white protein are not strong enough. However, ferric complexes prepared from egg white protein are partially stable.

The hydrolysis of the egg white protein can be carried out in one or more steps as is conventional. However, better results are obtained when the hydrolysis process includes an enzymatic hydrolysis step using an acid protease in an acid medium. Suitable acidic proteases are commercially available. Particularly convenient acid proteases can be obtained by controlled fermentation of fungae such as Aspergillus oryzae. These proteases contain both endo-peptidases and exo-peptidases. An example of such acidic enzyme is VALIDASE FP-60 (obtainable from Valley Research, Inc., in South Bend, Indiana).

The medium can be acidified using an inorganic grade or organic grade acid for food. Examples of acids that can be used are phosphoric, hydrochloric, sulfuric, lactic, malic, fumaric, gluconic, sussinic, ascorbic, or citric. The most preferred acid is phosphoric acid. The pH can be selected to provide optimum performance of the enzyme. The selected pH can be that in which the enzyme performs optimally. This information can be obtained from the supplier or by simple testing.

The hydrolyzed protein obtained after hydrolysis with the acid protease can be used in this form. However, the hydrolyzed protein can be further hydrolyzed if desired. For any additional enzymatic hydrolysis step that may be desired, any convenient enzyme can be used. Examples include but are not limited to ALCALASAE, FLAVORZYME and NEUTRASE, (Novo Nordisk A / S, Novo Alie, Denmark), and PROZYME and PANCREATIN (Amano International Enzyme Co., Inc., Troy, VA). The enzymes can be acid proteases, alkaline proteases or neutral proteases. Particularly convenient are alkaline proteases.

Before adding the ferric source to the partially hydrolyzed egg white protein, the partially hydrolyzed egg white protein should have an acidic pH of about 3.0 to about 5.5. If necessary, the pH can be adjusted by adding an inorganic or organic grade acid with convenient food grade quality as defined above. The most preferred acid is phosphoric acid.

The ferric solution and the partially hydrolyzed egg white protein are then combined. This is preferably carried out under stirring with the ferric solution added partially hydrolyzed egg white protein; preferably in a slow way. The amount of ferrous solution that is added can be selected to provide the desired ferric charge. However, it is surprisingly found that the binding of iron to the complex is related to the amount of iron limit. Optimal binding is obtained when the complex contains about 1% to about 2% or about 4.5% to about 10% dry weight of iron. Of course, ferric charges of more than 10% may be used but the binding, and stability of the complex, may be slightly lower.

After adding the ferric source to the partially hydrolyzed egg white protein, the solution must be neutralized to promote the formation of a ferric complex. However, the mixture should not be allowed to become basic to avoid precipitation and formation of hydroxide ions. A pH in the range of about 6.5 to about 7.5 is recommended.

If necessary, an alkali can be added to neutralize the pH of the mixture. Any food grade alkali can be used for neutralization and may include but is not limited to sodium hydroxide, potassium hydroxide, ammonia hydroxide, magnesium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate. Ammonium hydroxide is preferred.

All steps are preferably carried out under agitation.

The obtained complexes can be used in the form of liquid as obtained. More preferably, however, the complexes are dried to powder. The drying can be freeze dried or it can be spray dried. Any convenient procedure for freeze drying or sprinkling complexes to powder can be used. Suitable methods are known in the art.

In use, the complexes are included in the ingredients that constitute the desired foods or beverages and the ingredients processed in the normal manner. Although the bioavailability of iron may be slightly less than that of ferric sulfate, it is found to be well within acceptable limits. In most cases, the statistical difference in bioavailability is not significant. In addition, the complexes are found to be very stable and when used in foods and beverages, they do not lead to increased discoloration or generation of flavor loss. Moreover, it is found that complexes do not increase processing problems such as inlays.

The complexes are particularly convenient for use in foods or beverages in liquid form; for example infant formula concentrates and ready-to-drink beverages such as chocolate or malted milk drinks. These foods or beverages are normally subjected to retorting or other sterilization as part of their process and hence the ability of the complexes to withstand rough treatment provides a great improvement. However, the complexes can be used in other types of foods or beverages such as powdered drinks, infant formulas, and infant cereals.

The complexes can also be included in pet foods that normally contain lipids and vitamins.

It is perceived that the products containing the complexes have similar organoleptic properties and color compared to unfortified products. This offers the advantage that products can be fortified without causing noticeable changes that can adversely affect the consumer's perception.

Also, it is found that vitamin C is not degraded by complexes. Therefore, the complexes can be used in products that are intended to be nutritionally balanced.

Example 1 An amount of 1000 g of frozen egg white is added to a fermentor (Biostat® M) and allowed to thaw at room temperature. The pH is slowly adjusted to 3.0 using 85% H3P0 under stirring. The solution is then heated to 42 ° C. An amount of 2.5 g of an acid protease (VALIDASE FP60 obtained from Valley Research, Inc. in South Bend, Indiana) is added and the solution is allowed to react for 16 hours under low / medium agitation at a pH of 3.0 to 3.3. This acid protease is obtained from Aspergillus oryzae and contains both endo-peptidase and exo-peptidase.

After 16 hours of reaction, ammonium hydroxide (28%) is added to raise the pH to 7.4. An amount of 2.5 g of alkaline protease (ALCALASE 2.4L, obtained from Novo Nordisk A / S) is added and the temperature of the solution is raised to 50 ° C under stirring. This protease is obtained from a Bacillus licheniformis strain and contains endo-proteinase mainly. After 3 hours of reaction under low / medium stirring, the solution is cooled to room temperature. An amount of 43.5 g of 85% H3P04 is added followed by an amount of 5.0 g of FeS04.7H20 in 50 ml of H20, both under agitation. The pH is then adjusted to 6.7 with 28% NH40H under stirring. Then the solution is heated to a temperature of 90 ° C for 10 minutes. Then, the solution is cooled to room temperature.

The liquid ferric complex is collected.

Example 2 The process of Example 1 is repeated. Then an amount of 90 g of maltodextrin M.D.5 is added to the liquid ferric complex under agitation. The mixture is then spray-dried using a spray rotary disk spray dryer (Tension = 145 ° C, Tsalide = 80 ° C).

The ferric powder complex is collected.

Example 3 An amount of 1000 g of frozen egg white is added to a fermentor (Biostat® M) and allowed to thaw at room temperature. The pH is slowly adjusted to 3.0 using 85% H3P04 under stirring. The solution is then heated to 42 ° C. An amount of 2.5 g of an acid protease (VALIDASE FP60 obtained from Valley Research, Inc. in South Bend, Indiana) is added and the solution is allowed to react for 4 hours under low / medium agitation at a pH of 3.0 to 3.3.

After the reaction, the solution is allowed to cool to room temperature. An amount of 5.0 g of FeS04.7H20 in 50 ml of H20 is added, with stirring. The pH is then adjusted to 6.7 with 28% NH40H under stirring. Then the solution is heated to a temperature of 60 ° C for 10 minutes. Then, the solution is cooled to room temperature.

An amount of 90 g of maltodextrin M.D.5 is added to the solution under stirring. The mixture is then spray-dried using a spray rotary disk spray dryer (Tension = 145 ° C, T aiida = 80 ° C).

The ferric powder complex is collected.

Example 4 The process of Example 1 is repeated that the egg white is subjected to hydrolysis for 6 hours. The ferric powder complex is collected.

Example 5 Four chocolate milk drinks are prepared by reconstituting a chocolate milk powder (QUIK, Nestle USA, INC) at a concentration of 8.5% by weight. Each beverage contains 12.5 ppm of added iron in the form of a ferric complex different from one of examples 1 to 4.

The beverages are placed in sealed 125 ml glass bottles and autoclaved at approximately 121 ° C (250 FAHRENHEIT) for 5 minutes. The bottles are cooled to room temperature and stored for 6 months.

Beverages are evaluated for physical stability, color and taste after 1, 2, 3,4,5 and 6 months.

The taste is judged by a tasting group of 10 people. All beverages are judged as being without discoloration, sedimentation or coagulation and of a good flavor.

Example 6 Four chocolate milk drinks are prepared by reconstituting a chocolate milk powder (QUIK, Nestle USA, INC) at a concentration of 8.5% by weight. Each beverage contains 12.5 ppm of added iron in the form of a ferric complex different from one of examples 1 to 4.

The beverages are preheated to approximately 80 ° C (175 FAHRENHEIT), heated to approximately 140 ° C (285 FAHRENHEIT) by steam injection, kept at this temperature for 5 seconds, and cooled to approximately 80 ° C (175 FAHRENHEIT). The beverages are then homogenized at approximately 17 / 3.5 MPa (2500/500 psi), cooled to approximately 16 ° C (60 FAHRENHEIT) and poured into Tetra Brik Aseptic® 250 ml containers (Tetra Pak Inc., Chicago IL).

Drinks are evaluated for physical stability, color and taste after 1 day, 2 weeks, and 1 and 2 months. The taste is judged by a tasting group of 10 people. All beverages are judged as coming without fading, sedimentation or coagulation and a good taste. Example 7 Four chocolate milk drinks are prepared by reconstituting a chocolate milk powder (QUIK, Nestle USA, INC) at a concentration of 8.5% by weight. Each beverage contains 12.5 ppm of added iron in the form of a ferric complex different from one of examples 1 to 4.

The beverages are preheated to approximately 80 ° C (175 FAHRENHEIT), heated to approximately 1480 ° C (298 FAHRENHEIT) by steam injection, kept at this temperature for 5 seconds, and cooled to approximately 80 ° C (175 FAHRENHEIT). The beverages are then homogenized at approximately 17 / 3.5 MPa (2500/500 pei), cooled to approximately 16 ° C (60 FAHRENHEIT) and poured into Tetra Brik Aseptic® 250 ml containers (Tetra Pak Inc., Chicago IL).

Beverages are evaluated for physical stability, color and taste after 1, 2, 3, 4, 5, and 6 months. The taste is judged by a tasting group of 10 people. All beverages are judged as being without fading, sedimentation or coagulation and a good taste Example 8 Six drinks are prepared; 3 reconstituting a chocolate milk powder (QUIK, Nestlé USA, Inc) and 3 reconstituting a malted powder (MILO, Nestle Australia S.A.). Each beverage comprises 22.0 g of powder in 180 ml of boiling water. A ferric complex of each of examples 2 to 4 is added to both a chocolate drink and a malted beverage. The final ferric concentrations in chocolate drinks are 15.0 ppm and in malted drinks are 25.0 ppm.

The drink is stirred briefly and allowed to sit for 15 minutes at room temperature. After 15 minutes, the drinks are judged by a tasting group of 10 people. No change in color or change of flavors was found when the samples were compared with the control samples without added iron.

Example 9 Three infant cereal meals are prepared by reconstituting 55 g of infant cereal containing banana (Nestlé USA, Inc) with 180 ml of boiling water. The ferric complexes of Examples 2 to 4 were added to each cereal to provide 7.5 mg of iron per 100 g of cereal powder.

Each cereal food is briefly stirred and allowed to sit for 15 minutes at room temperature. After 15 minutes, cereal meals are judged by a tasting group of 10 people. No change in color or change of flavors was found when the samples were compared with the control samples without added iron.

Example 10 The biodisposition of the complexes is determined as follows: Animals: - The animals used are Sprague-Dawley rats at the weaning stage of 3 weeks of age (IFFA-CREDO, L'Arbresle, France).

Diets: -The control diet is a low iron ICN diet (Soccochim SA, Lausanne, Switzerland) that has a ferric volume of 3 mg / kg. This diet is based on casein and provides the nutritional requirements of growing rats except iron.

The experimental diets are: Diet A: - The control diet supplemented with FeS04.7H20 to provide 10 mg / kg of iron.

Diet B: - The control diet supplemented with FeS04.7H20 FeS04.7H20 to provide 20 mg / kg of iron.

Diet 1: - The control diet supplemented with the complex of example 4 to provide 10 mg / kg of iron.

Diet 2: - The control diet supplemented with the complex of Example 4 to provide 20 mg / kg of iron.

Diet 3: - The control diet supplemented with the complex of Example 24 to provide 10 mg / kg of iron.

Diet 4: - The control diet supplemented with the complex of Example 24 to provide 20 mg / kg of iron.

Analytical methods 1) The hemoglobin analysis is done by anesthetizing the rats with isoflurane and then extracting a 200 ml sample of orbital venous plexus blood. The blood hemoglobin level in the sample is determined by the cyanmethemoglobin method (Hb MPR 3 equipment, Boehringer Mannheim GmbH, Germany), using an automated instrument (Hemocue, SA Baumann-Medical SA, Wetzikon, Switzerland). Commercial quality control blood samples (Dia-HT Kontrollblut, Dia MED, Cressier, Switzerland) having a variety of hemoglobin levels are measured with all hemoglobin determinations. 2) The bioavailability of iron compared to ferric sulfate heptahydrate is evaluated using a slope-proportion calculation based on hemoglobin levels. A multiple regression equation relates the amounts of iron added to hemoglobin levels. The equation provides a straight line per diet that intercepts wax doses. The bioavailability of the iron source in relation to ferric sulfate heptahydrate is then calculated as the ratio of the two slopes. The ratio is multiplied by 100 to provide the relative bioavailability value.

Procedure: - the rats are housed individually in polycarbonate cages, provided with stainless steel bars. Animals are allowed free access to distilled water. To make rats anemic, rats have ad libi tum access to the control diet for 24 days. A fresh diet is provided daily. The waste of the diet by the rats is reduced by covering the diet with a fence.

After 24 days, hemoglobin and weight are determined. Seventy rats with hemoglobin levels between 4.5 and 5.8 are formed into 7 random groups of 10 that have an approximately equal mean of hemoglobin and body weight. Each group of animals is fed one of the experimental diets for 14 days. Rats are fed ad libitum from diets that start with 20 g / day on day 0. Rats have free access to distilled water. The consumption of individual food is measured daily. After 14 days, the rats are weighed and the hemoglobin is determined.

Results The average food intake and iron intake is not affected by the type of iron source. However, rats that did not receive added iron ate less than those that received iron. Rats that consumed diets with 20 mg / kg of iron added consumed slightly more of those diets than those that received diets with 10 mg / kg of iron.

The weight gain in rats is not affected by the type of iron source. However, rats that did not receive added iron gained less weight than those that received iron. Rats that received diets with 20 mg / kg of iron added gained slightly more weight than those that received diets with 10 mg / kg of iron.

Blood levels of hemoglobin at the beginning and end of the period are shown in the Table below.

The relative bioavailability is as follows The bioavailability of all iron protein complexes are similar to that of ferrous sulfate. A relative bioavailability value of less than 91% is understood to be significantly lower than the reference. Accordingly, from a statistical point of view, the relative bioavailability values of the ferric complexes of Example 2 are similar to those of ferrous sulfate. However, from a practical point of view, all the complexes have a very good bioavailability.

Claims (13)

1. Iron protein hydrolyzate complex comprising gelatinized ferric ions of egg white protein to partially hydrolyzed egg having a molecular weight in the range of about 2'000 to about 106'000.

2. The complex according to claim 1, wherein the partially hydrolysed egg white egg protein is microbial protease hydrolyzate.

3. Complex according to claim 2, wherein the microbial protease is obtained from Aspergillus oryzae and contains both endo-peptidase and exopeptidase.

4. The complex according to claim 1, wherein the partially hydrolysed egg white egg protein is a microbial protease hydrolyzate which is obtained by hydrolyzing the egg white protein with a protease that is obtained from Aspergillus oryzae and contains both endo-peptidase and exo-peptidase, and a protease that is obtained from Bacillus licheniformis and contains endo-proteinase.

5. Complex according to claim 1, containing about 1% to about 2% or about 4.5% to about 10% by dry weight of ferric ions.

6. Complex according to claim 1, which is stable at a neutral pH but dissociates at a pH below about 3.

7. Complex according to any of the preceding claims, which contains about 1% to about 2% or about 4.5% to about 10% by dry weight of ferric ions.

8. Sterilized liquid beverage containing lipids and a stable iron fortification system, the iron fortification system comprises an iron protein hydrolyzate complex according to any of the preceding claims.

9. Sterile liquid beverage containing phenols and a stable iron fortification system, the iron fortification system comprises an iron protein hydrolyzate complex according to any of claims 1 to 7.

10. Beverage according to claim 9, which is a tea beverage.

11. Drinking powder containing lipids and a stable iron fortification system, the iron fortification system comprises an iron protein hydrolyzate complex according to any of claims 1 to 7.

12. Beverage powder according to claim 11, which contains cocoa.

13. Process for preparing an iron fortification system, including an iron protein hydrolyzate complex according to any of claims 1 to 7, the process comprises: enzymatically hydrolyzing an egg white protein using a microbial protease to provide a protein of partially hydrolyzed egg white; add an iron source to partially hydrolyzed egg white protein under acidic conditions; and raising the pH to 6.5 to 7.5 to form a partially hydrolysed egg white protein hydrolyzate complex as the iron fortification system.