WO2004066753A1

WO2004066753A1 - Milk product in dry form comprising unesterified sterol

Info

Publication number: WO2004066753A1
Application number: PCT/EP2003/000880
Authority: WO
Inventors: Michel John Arthur Groux; Martin Leser; Alvin Berger
Original assignee: Nestec SA
Current assignee: Nestec SA
Priority date: 2003-01-29
Filing date: 2003-01-29
Publication date: 2004-08-12
Anticipated expiration: 2005-07-29
Also published as: AU2003303848A1

Abstract

A composition in dry form comprises an unesterified sterol, a crystal modifier including sorbitan tristearate (STS) and a compound taken from the group consisting of milk, soy, milk derivative, soy derivative or a mixture thereof. Preferred embodiments include an additional compound selected from the group consisting of sorbitan monostearate (SMS), one or more monoglycerides, one or more diglycerides, propyleneglycolmonosterate (PGMS) or a combination of two or more thereof. The composition can be used for lowering LDL cholesterol levels.

Description

Milk Product in dry form Comprising Unesterified Sterol

The present invention relates to a composition in dry form comprising an unesterified sterol and a crystal modifier and a method for production of the composition. The composition can be used for reducing LDL cholesterol concentration. In addition the invention relates to a method for production of the composition, use of the composition in reducing LDL cholesterol concentration, use of the composition in the manufacture of a functional food product or medicament for the treatment or prevention of high LDL cholesterol concentration and a method of treatment or prevention of high LDL cholesterol concentration which comprises administration or consumption of the composition.

Within the context of this specification the word "comprises" is taken to mean "includes, among other things". It is not intended to be construed as "consists of only".

It is well known that a high concentration of LDL cholesterol is associated with the problems of serious health risks including heart disease, atherosclerosis, high blood pressure, and cardiovascular conditions. A typical western diet exacerbates this problem because it is itself high in cholesterol and dietary lipids that lead to increased circulating LDL cholesterol in humans. In view of the risk, a diet low in cholesterol is generally recommended which typically includes fruits, vegetables, and grains, and a minimum of red meat, eggs, and fried food.

Furthermore, it has been observed that consumers generally prefer foods high in saturated fats, because of their sensory attributes including mouth feel, texture, and flavours associated with these foods. In contrast, diets rich in fruits, vegetables, and grains appear to be less desirable. In the light of this, there is a need for new food products which taste desirable, but which do not have negative health characteristics associated with foods having large amounts of fat. In addition, there is a need for new foods which counter the negative effects of a diet which provides large amounts of cholesterol.

Sterols, which include phytosterols, stanols, esters of stanols, esters of phytosterols, oligosidic derivatives fo the above and combinations thereof are known to lower cholesterol levels in humans when eaten on a regular basis and in a sufficient amount. It is known that sterols lower cholesterol by binding to sites in the gastrointestinal tract and competing with cholesterol for binding sites, thus inhibiting the absorption of cholesterol. Plant sterols have structures that are similar to cholesterol, but differ by having ethyl, methyl groups or unsaturated groups in their side chain. Because of their structural similarities to cholesterol, plant sterols are capable of inhibiting cholesterol absorption. However, despite the fact that sterols are present in high concentrations in plants such as corn, rice, and soybean, the sterols are largely removed during processing and are not consumed. Therefore, typical foods consumed in typical quantities, of a human diet generally do not contain sufficient amounts of sterols to contribute effectively to reducing cholesterol absorption.

In order to obtain an adequate amount of sterol required to lower cholesterol levels, the diet must be supplemented. Therefore, there is a demand for new foods which deliver sufficient amounts of sterols to humans to lower their cholesterol concentrations.

Thus, a key issue regarding the use of sterols for their cholesterol-lowering properties concerns their bioavailability, which is linked to their molecular state within food matrices - sterols are able to decrease cholesterol absorption only when solubilized in molecular (uncrystallised) form. Thus, simply increasing the amount of sterols in a diet does not ensure that cholesterol levels are lowered because even if sterols are included in a person's diet the benefits of consuming sterols may not be obtained. In particular, sterols in the form of crystals, are not readily absorbed by the gastrointestinal (GI) tract. In contrast, sterols must be in a solubilized form in order that they can be absorbed by the GI tract.

Therefore, overcoming the problem of solubilization of sterols in food matrices represents a key challenge in the formulation of anti-cholesterol foods. Research in this area has been focussed on increasing solubility by production of esterified and hydrogenated sterols or esterified and non- hydrogenated sterols and known products are on the market, such as spreads, salad dressings and yogurts which include this form of sterol. All sterols available on the market today suffer from the problem that they are very poorly soluble in unesterified form.

A composition comprising one or more sterols is described in US patent no. 6190720. The composition has one or more sterols, one or more fats and one or more emulsifiers and it is suggested that the disclosed composition can be used as an agent for lowering cholesterol levels. However, it has been found that the known compositions comprising sterols are not stable and therefore they do not have a long shelf-life. Within the context of this specification not stable is taken to include 1) separation of fat and water phases, and 2) recrystalisation of sterols.

The present invention addresses the problems set out above.

Remarkably, it has now been found that a composition in dry form comprising a crystal modifier selected from the group consisting of sorbitan tristearate (STS) provides a stable composition wherein sterols are kept in molecular form for a shelf-life of at least several months.

Consequently, in a first aspect the present invention provides a composition dry form which comprises an unesterified sterol, a crystal modifier comprising sorbitan tristearate (STS) and a compound taken from the group consisting of milk, soy, milk derivative, soy derivative or a mixture thereof.

Preferably, an embodiment of a composition in dry form according to the present invention comprises a crystal modifier which includes sorbitan tristearate (STS) and optionally additionally comprises an additional compound selected from the group consisting of sorbitan monostearate (SMS) , one or more monoglycerides, one or more diglycerides, propyleneglycolmonosterate (PGMS) or a combination of two or more thereof. This composition provides the advantage that sterols remain in a stable molecular form and unlike previously known products the composition therefore has a long shelf life. Remarkably, the composition provides a product having a long shelf life at room temperature (even under tropical conditions) .

Preferably the monoglycerides are provided in the form of saturated distilled monoglycerides, eg Dimodan PV (TM) .

Preferably an embodiment comprises at least one monoglyceride and at least one diglyceride.

Preferably, an embodiment of a composition according to the present invention comprises STS in an amount of from about 50% to about 200% by weight the amount of sterol in the composition. More preferably it is about the same amount of sterol by weight.

Preferably, an embodiment of a composition according to the present invention comprising a mixture of STS and SMS comprises STS and SMS in an amount of from about 50% to about 200% by weight the amount of sterol in the composition. More preferably it is about the same amount of sterol by weight. Preferably the amount of SMS in the mixture is from about 15% to about 35% by weight the total amount of the mixture of STS and SMS. More preferably, the amount of SMS in the mixture is about 25% by weight the total amount of the mixture of STS and SMS.

Preferably, an embodiment of a composition according to the present invention comprising a mixture of STS and PGMS comprises STS and PGMS in an amount of from about 50% to about 200% by weight the amount of sterol in the composition. More preferably it is about the same amount of sterol by weight. Preferably the amount of PGMS in the mixture is from about 15% to about 35% by weight the total amount of the mixture of STS and PGMS. More preferably, the amount of PGMS in the mixture is about 25% by weight the total amount of the mixture of STS and PGMS.

Preferably, an embodiment of a composition according to the present invention comprising a mixture of STS and saturated distilled monoglyceride comprises STS and saturated distilled monoglyceride in an amount of from about 50% to about 200% by weight the amount of sterol in the composition. More preferably it is about the same amount of sterol by weight. Preferably the amount of saturated distilled monoglyceride in the mixture is from about 15% to about 35% by weight the total amount of the mixture of STS and saturated distilled monoglyceride. More preferably, the amount of saturated distilled monoglyceride in the mixture is about 25% by weight the total amount of the mixture of STS and saturated distilled monoglyceride.

Preferably, an embodiment of a composition according to the present invention comprises a sterol selected from the group consisting of unesterified sterols. More preferably the sterol is selected from the group consisting of unhydrogenated sterols. Even more preferably, the sterol is predominantly from soy origin and non-hydrogenated. Most preferably it has a purity of about 90% or more in a powder form, its colour is white and not-discoloured, its particle size is fine and there is no off-taste.

This provides the advantage that the sterol is not subject to the risk of contamination with heavy metals including lead. These metals have been present as contaminants in the solvents used for dissolving sterols in known products. Preferably, an embodiment of a composition according to the present invention comprises sterol in an amount of about 400mg to about 1200mg per serving, more preferably about 600mg to about 800mg per serving, wherein the quantity can be taken in one or several times during the day. These amounts refer to the amount of pure sterol in the composition. The powder is reconstituted in the desired amount of water, for example in 200 to 250 ml of liquid.

The composition in dry form according to the present invention comprises milk. Preferably the milk comprises about 8 % to about 24% by weight fat, more preferably between 10 and 15% by weight fat (including emulsifier) . Preferably an embodiment of a composition according to the present invention comprises from about 67 to 85 % skim milk solids, preferably between between 78 and 83 % skim milk solids. The humidity of the composition is around 2.5 to 4 %. The sterols are in an amount comprised between 1.5 and 5 %.

Preferably the milk is cows milk or milk from another source including soy milk. Alternatively the milk can be a fat free or low fat aqueous extract including for example whey. The milk derivative is casein or milk proteins obtained by ultrefiltration. The soy derivative is soy isolate or soy concentrate.

Preferably, an embodiment of a composition according to the present invention comprises oil. Preferably the oil is a vegetable oil having applicable amounts of mono-unsaturated and polyunsaturated fatty acids. Preferably the oil comprises rapeseed oil and/or corn oil. Preferably an embodiment of a composition according to the present invention comprises from about 3% to about 7% by weight rapeseed oil, more preferably about 4% to about 6% by weight rapeseed oil, most preferably about 5% by weight rapeseed oil. Preferably an embodiment of a composition according to the present invention comprises from about 2% to about 5% by weight corn oil, more preferably about 3% to about 4% by weight corn oil, most preferably about 3.5% by weight corn oil .

In preferred embodiments the composition is optionally enriched with vitamins and or minerals including calcium. This provides the advantage of a balanced nutritional composition which is, for example, beneficial to bone formation and/ or inhibits reduction of bone mass.

In preferred embodiments the composition is optionally flavoured. This provides the advantage that an embodiment of the composition has a good taste which increases desirability of the composition.

In preferred embodiments, the composition includes a sweetener. Preferably the sweetener is sugar although other known sweeteners can be included.

In a preferred embodiment, one or more oligosaccharides and/or polysaccharides are included. The polysaccharide (s) provide the advantage that they are capable of suspending insoluble minerals which may also be included, for example calcium carbonate (CaC0₃) . The oligosacchrides provide the advantages associated with prebiotics including promotion of gut health. In a second aspect the invention provides a method for production of the composition which comprises the steps of: i) integrating a sterol in an oily matrix comprising at least one crystal modifier; ii) transferring the oily matrix to a milk aqueous phase in such a manner that the oily matrix remains intact and a proper emulsion is obtained by homogeneisation; and iii) drying the oil in water emulsion to obtain a powder.

Under milk , we understand in the present specification, liquid milk, liquid soy, liquid milk derivative, liquid soy derivative or a mixture thereof. According to a preferred embodiment of the process of the invention, the liquid milk is concentrated before mixing with the oily matrix.

Preferably, an embodiment of a method according to the invention comprises the steps of heating and keeping the oily matrix at about 80 °C preferably until a clear solution is obtained. Preferably sterol is added to the oily matrix consisting of or comprising STS and the oily matrix is maintained at 80 °C.

Preferably, a water phase comprising milk is prewarmed to about 80°C and the oily matrix is added to the prewarmed water phase.

Preferably the oil in water emulsion is kept at 80 °C and is not cooled below 80°C until further processing is carried out.

Preferably the composition is dryed, either by spray-drying or by freeze-drying.

According to an example, the process according to the invention comprises the steps of forming a first solution by emulsifying oils, emulsifier and sterols at a temperature of at least 85 °C; and separately forming a second solution by prewarming skimmed milk at a temperature of at least 80 °C. The two solution are mixed to form a mixture and stored at a temperature of at least 80°C. The mixture is subjected to further processing including homogenizing and drying. The mixture is then ready to be packaged bulk or formed into tablets or pills.

In a third aspect the invention provides use of a composition obtained by reconstituting in water the composition according to an embodiment of the invention in reducing LDL cholesterol concentration. The international Patent Application PCT/EP 02/07952 is based on a liquid formulation. The present invention concerns a powder and it has been shown that the same benefits are also present in said powder form.

In a fourth embodiment the invention provides use of the composition in the manufacture of a functional food product or medicament for the treatment or prevention of high LDL cholesterol concentration. The composition in dry form is mixed with any possible vehicle known in the art and sold in said dry form under tablets, pills or others. It is then possible either to swallow the product per se, or reconstitute in water.

In a fifth embodiment the invention provides a method of treatment or prevention of high LDL cholesterol concentration which comprises administration or provision of the composition in dry form for consumption.

Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which:

Figure 1 shows micro-photographs illustrating the emulsion obtained according to the present invention;

Figure 2 shows micro-photographs illustrating an emulsion obtained according to the prior art for illustration only;

Figure 3 shows electronically generated images of microscope slides showing embodiments of a milk product comprising sterols which have very few crystalline plant sterols. These embodiments are considered to be biologically active at inhibiting the absorption of cholesterol.

For the purposes of clarity and a concise description features are described herein as part of the same or separate embodiments, however it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

As seen in Figures 1 and 2 an embodiment of a composition according to the invention is smooth and provides sterols which are integrated in the composition in a molecular form. In contrast a similar composition according to the prior art has sterols which have crystallised to form needle like structures .

Claims

1. A composition in dry form which comprises an unesterified sterol, a crystal modifier comprising sorbitan tristearate

(STS) and a compound taken from the group consisting of milk, soy, milk derivative, soy derivative or a mixture thereof.

2. A composition according to claim 1 which comprises a crystal modifier which includes sorbitan tristearate (STS) and optionally additionally comprises an additional compound selected from the group consisting of sorbitan monostearate (SMS) , one or more monoglycerides, one or more diglycerides, propyleneglycolmonosterate (PGMS) or a combination of two or more thereof.

3. A composition according to claim 1 or 2 wherein the monoglycerides are provided in the form of saturated distilled monoglycerides.

4. A composition according to claim 1 or 2 wherein the crystal modifier is in an amount of from about 50% to about 200% by weight the amount of sterol in the composition.

5. A composition according to any preceding claim comprising a mixture of STS and SMS wherein the amount of SMS in the mixture is from about 15% to about 35% by weight the total amount of the mixture, of STS and SMS.

6. A composition according to any one of claims 1 to 4 comprising a mixture of STS and PGMS wherein the amount of PGMS in the mixture is from about 15% to about 35% by weight the total amount of the mixture of STS and PGMS.

7. A composition according to any one of claims 1 to 4 comprising a mixture of STS and monoglyceride wherein the amount of monoglyceride in the mixture is from about 15% to about 35% by weight the total amount of the mixture of STS and monoglyceride.

8. A composition according to any preceding claim wherein the sterol is selected from the group consisting of unesterified sterols.

9. A composition according to any preceding claim wherein the sterol is selected from the group consisting of unhydrogenated sterols.

10. A composition according to any preceding claim wherein the sterol is predominantly from soy origin.

11. A composition according to any preceding claim wherein the sterol has a purity of about 90% or more in a powder form, its colour is white and not-discoloured, its particle size is fine and there is no off-taste.

12. A composition according to any preceding claim wherein the sterol is in an amount of about 400mg to about 1200mg per serving and one serving comprises about 200ml to about 250ml of composition.

13. A composition according to any preceding claim which comprises a vegetable oil having mono-unsaturated and polyunsaturated fatty acids.

14. A composition according to claim 11 wherein the oil comprises rapeseed oil and/or corn oil.

15. A method for production of a composition according to any preceding claim which comprises the steps of: i) integrating a sterol in an oily matrix comprising at least one crystal modifier; ii) transferring the oily matrix to a milk aqueous phase in such a manner that the oily matrix remains intact and a proper emulsion is obtained by homogeneisation; and iii) drying the oil in water emulsion to obtain a powder.

16. A method according to claim 15 which comprises the steps of heating and keeping the oily matrix at about 80 °C preferably until a clear solution is obtained; adding sterol to the oily matrix consisting of or comprising STS and maintaining the oily matrix at 80 °C.

17. A method according to claim 15 or 16 wherein a water phase comprising milk is prewarmed to about 80°C and the oily matrix is added to the prewarmed water phase to create an oil in water emulsion.

18. A method according to claim 17 wherein the oil in water emulsion is kept at 80 °C and is not cooled below 80°C until further processing is carried out.

19. Use of a composition obtained by reconstituting in water the composition according to any of claims 1 to 14 in reducing LDL cholesterol concentration.

20. Use of a composition according to any one of claims 1 to 14 in the manufacture of a functional food product or medicament for the treatment or prevention of high LDL cholesterol concentration

21. A method of treatment or prevention of high LDL cholesterol concentration which comprises administration or provision of a composition according to any one of claims 1 to 15 for consumption.