DD296198A5 - PROCESS FOR THE PRODUCTION OF DAIRY PRODUCTS WITH A REDUCED STEROLINE CONTENT, IN PARTICULAR CHOLESTERIN - Google Patents

Abstract

The present invention relates to a process for the preparation of dairy products with reduced levels of sterols, in particular cholesterol, characterized in that it consists essentially in contacting a milk fat-containing OEI-in-water emulsion with cyclodextrin in sufficient quantity so that it forms inclusion complexes with the sterols, so that the latter can be extracted from the fat, and so that at the same time, or at the same time, said complexes can at least partly be separated from the environment, without causing an inversion of the OEl in Water output emulsion comes.

Description

Field of application of the invention

The starting materials used in the process according to the invention are oil-in-water emulsions containing milk fats, such as milk or cream. Milk is a liquid secreted by the mammary glands of female mammals. It consists of five main components:

- the lipids, especially in the form of triglycerides,

- the proteins,

- the sugars

- the salts,

- and the water.

Cream is a milk enriched by creaming by leaving the milk or centrifuge skimming with fat. you

contains the same main ingredients as the milk, but in different proportions.

These two products also contain ingredients that are present in very small quantities, such as lecithins, vitamins, Enzymes, dissolved gases, naturally present in the milk and / or resulting from the hydrolysis of the triglycerides Fatty acids, and sterols. The latter are represented mainly by the 98% cholesterol, and it's the fat

attached substances. The fat of cow's milk contains about 0.3% cholesterol, equal to 0.1 g per liter of milk.

Now it has been proven for a very long time that high blood cholesterol levels (cholesterol LDL) are associated with severe cardiac and respiratory depression Vascular diseases are directly related. The most important among these diseases is atherosclerosis, which in

damage to the arterial walls is expressed and one of its causes in a localized, excessive and abnormal deposition of cholesterol on the inner surface of an arterial wall. The resulting atheroma can lead to tragic consequences such as myocardial infarction. By way of example, a reduction in the

Total hemolertoscopic level by 1% leads to a 2% reduction in heart attack risk. Cholesterol over can

also be the cause of gallstones.

Prevention is one of the most effective ways to counteract these diseases. It can be that

the intake of cholesterol rich foods is reduced as much as possible or that foods with reduced cholesterol content are consumed.

It is therefore a concern of food producers, the cholesterol from the products of daily needs and before

everything from dairy products.

Thus, various methods have already been proposed for extracting the sterols from the fats. One of these methods is that the fat of animal origin is brought into contact with digitonin, which causes the Property has to react with cholesterol, causing a precipitate. The performance and the results

This method is unsatisfactory because of the difficulty of separating the precipitate from the environment. This method is definitely not applicable under industrial conditions.

Cholesterol can also be extracted from fat with the help of a solvent by entrainment. The main disadvantage of this Procedure is that the solvents commonly used are toxic and that there are always traces in the

remaining fats.

There are also methods of micro-distillation, which are industrially not applicable, or the column adsorption, as they

For example, in European Patent Applications EP-PS-0174848 and EP-PS-O318326 is known. These

Applications relate to a method according to which the fat held in a liquid state through a column with Adsorbent, in the present case activated carbon, is passed. It is clear that such a procedure is very difficult to apply

and, moreover, the extraction that can be achieved with it is not selective.

Another physico-chemical extraction method of cholesterol from fat is disclosed by Japanese Patent Application J P-PS-59/140299. It is that a cholesterol-containing dry matter, such as milk powder, with

supercritical CO _{2 is} brought into contact at a temperature between 35 and 45 ° C and a pressure between 130 and 200 atm. The realization of these physical conditions requires the use of complicated and expensive equipment. Therefore, the implementation of the method is very difficult. In addition, other lipid compounds, as it is called in the patent application, by the supercritical CO; carried away. This procedure is therefore not selective.

In order to eliminate sterols from fats, a process of biodegradation of the said sterols was also conceived

patent application EP-PS-0278794 using bacteria which, when combined with the fat in

Be able to metabolize at least one of the sterols containing the fat. Like all Processes in which fermentation processes play a role, this method of biodegradation due to the

living matter own variability difficult to perform. In addition, the substances used and the comparatively long duration are, inter alia, reasons which make such a process expensive. And finally, absolutely nothing is known about the nature and toxicity of the catabolites that arise in these fermentation processes, and they are certainly present in the fats treated in this way.

It is also of the European patent application EP-PS-0256911 a method for the elimination of the fat in animal Originated cholesterol known. It is based on the already worked up properties of the annular ones Cyclodextrin polyglucoses of truncated cone-like conformation and with 6,7 or 8 basic glucose building blocks

Alpha, Beta, or Gamma, respectively, in the hydrophobic cavity in their midst, take up sterol molecules, and especially cholesterol molecules, to form water-soluble inclusion complexes. According to the method, the liquid-containing fat is brought into contact with a cyclodextrin with stirring for 30 minutes to 10 hours, so that the

Formation of complexes is possible. The deposition of the latter is then carried out by water in the reaction medium

is added, which makes these complexes soluble. The aqueous solution prepared in this way is then after

Decantation collected.

The extraction yield of cholesterol by this method is not very high. It is at best only 41% and this after three successive extractions, as indicated in Example 3 of the description of this European patent application. It should be noted that according to this method, the fat must be kept molten in an atmosphere without oxygen. Due to these technical properties, a specific apparatus for keeping the temperature constant and supplying neutral gas must be used. Finally, the period of time required for the first phase of complex formation alone is at least 30 minutes and, in fact, 2 to 3 hours, as indicated in the examples. This process is therefore necessarily time, material and energy consuming. Apart from these unsatisfactory achievements, this process represents a succession of additional stages in the production of a food and would be somewhat unreasonable as an industrial process. First, it is to produce the fat in an anhydrous form, then subject it to heavy cholesterol extraction treatment, and then place it in a suitable state where it would be useful for a method of making food. In the case of milk fat, these foods may be milk powder dairy, yoghurt, cheese or others. It is clear that such a scheme is unacceptable in terms of industrial profitability. It follows from the above facts that hitherto, none of the prior art solutions has been able to satisfactorily produce low-sterling, particularly low-cholesterol food fats, that is, in such a manner as to satisfy the industrial conditions of economic viability, flexibility the application and quality of the finished products.

In addition, in the context of the quality of finished products made using known methods, it is important to note that, like any mitoch fat, these products may oxidize and become rancid, making them unsuitable for human consumption. Milk fat contains unsaturated compounds that react easily with atmospheric oxygen. This is the reason why it is provided in the method described in the above-mentioned patent application EP-PS-0256911 to operate under nitrogen. Nevertheless, the products treated in this way become very rancid, which inevitably affects their value as food.

Object of the invention

One of the main objects of the present invention is therefore to counteract these disadvantages of the aforementioned known prior art and to present a process for the production of dairy products with a reduced content of sterol and in particular of cholesterol. As a result, it is no longer about it. To extract sterols from intermediates, which are the animal fats, but to incorporate the elimination of sterols in the production of dairy products.

Explanation of the essence of the invention

However, this reformulation of the technical problem, even if it seems a priori logical, was not obvious, because there are a number of technical obstacles and prejudices that have never been overcome, even though the problems associated with food cholesterol have long been known ,

In the first place, it must be understood that oil-water milk emulsions such as milk and cream are heterogeneous and complex environments consisting of colloidal particle suspensions (fat globules and protein minicells) in a dispersing aqueous phase. Cholesterol accounts for only a minor proportion of the many other free substances, such as fatty acid proteins. In addition, it is incorporated into the membrane structure of the fat globules. So it is not directly accessible a priori. From these findings, it was reasonably concluded that cyclodextrin contacted with such a milieu had no particular affinity for the cholesterol due to the strong competition between the compounds of the environment for the cyclodextrin and the position of the cholesterol in the membranes of the fat globules should have.

Second, even assuming that the cyclodextrin would complex the cholesterol, it would be feared that an emulsion inversion phenomenon would appear due to the known role of cholesterol in stabilizing the membrane structure of the fat globules forming the oil-in-water emulsion , It is obvious that a milk environment in which emulsion inversion has taken place is no longer a starting material for the production of many dairy products. To use it, it would be necessary to re-treat it using, for example, exogenous emulsifying agents. In this case, the deficiency of the known methods were encountered.

Third, in a reference book ("Science du lait", Charles ALAIS, page 102), it is stated that cholesterol also acts as an inhibitor of lipases, which are the cause of rancidity of oil-in-water milk emulsions an obstacle to the development of ideas of extraction of cholesterol from such environments.The applicant, by resisting all these technical prejudices, has proved an inventive approach and developed the method according to the invention.

Thus, after a whole series of research and experiments, mainly conducted in the Department of Fine Chemistry of the IRHO-CIRAD, the applicant demonstrated, in a completely surprising and unexpected way, the fact that it was possible to produce dairy products with reduced levels of sterols, in particular cholesterol, by contacting an oil-in-water emulsion containing milk fats with cyclodextrin in sufficient quantity to form inclusion complexes with the sterols so that the latter can be extracted from the fat and simultaneously or not simultaneously said complexes can be separated from the environment without the starting oil-in-water emulsion being turned into a water-in-oil emulsion.

It has first been found that cyclodextrin under the conditions of the process is a remarkably selective Affinity to that on the surface of the fat globules contained in the oil-in-water milk emulsion,

has existing cholesterol.

It has also been found that the starting oil-in-water emulsion does not reverse to a water-in-oil emulsion

despite the elimination of cholesterol, which is believed to be an important component of the physical stability of the emulsion due to its surfactant role.

In addition, the fat is integrated in the process of the invention in an oil-in-water emulsion, making it possible,

to limit its contact with atmospheric oxygen and, as a result, the phenomena of oxidation.

In addition, and even more unexpected and advantageous, those produced by the method according to the invention Dairy products based on comparative products an increased resistance to oxidation. So are the problems of Rancidity, which leads to the appearance of a repulsive taste in dairy products, by the application

the method according to the invention at least partially solved. This is all the more surprising as, as already mentioned, the extracted cholesterol is known to inhibit the action of the lipases involved in the phenomena of oxidation.

Without this being a limitation to the present invention, it can be assumed that these Improving the oxidation resistance of the dairy products according to the invention over old to the fact

attributed to the fact that the free fatty acids naturally present in milk fat or derived from the lipolysis of the triglycerides also complex with the cyclodextrin and at the same time as the cyclodextrin cholesterol

Complexes are deposited. These often unsaturated free fatty acids have a strong tendency to oxidize and

This can cause the oxidation of other unsaturated compounds in the fat, such as triglycerides

Vitamins and the phospholipids. This tendency to oxidation can be estimated by measuring the acid number while the peroxide number

is a significant parameter for the oxidative strength of milk fats and products containing them.

According to the present invention, the starting oil-in-water emulsion used may be any or all of the milk or cream

of animal origin (cattle or other) and of any kind.

The distinction between milk and cream takes into account the fact that the former a fat concentration

less than or equal to 10% by weight while the other is greater than 10% by weight.

The milk or cream can be raw, thermally treated (pasteurization, UHT sterilization), enriched with fat,

homogenized or reconstituted, for example based on anhydrous milk fat and skimmed milk.

In the context of the invention, the term "cyclodextrin" is to be understood as including the following constituents:

annular and from 6,7 or 8 glucopyranose units, of which at least one may be mono- or polysubstituted, existing oligosaccharides, the polymers whose monomers consist of the ring-shaped oligosaccharides, as well as these on inert carrier grafted or fixed products.

The cyclodextrin used can therefore be of the alpha, beta or gamma type, preferably of the beta type, substituted or

be unsubstituted. The mono- or polysubstituierenden groups of cyclodextrin can in particular alkyls such as

Hydroxypropyl or saccharides of the glycosyl or maltosyl type or others. The crosslinked or uncrosslinked cyclodextrin in polymerizable form used in the process of the invention

may, for example, the cyclodextrin type, which by polymerization of cyclodextrin monomers with

Epichlorohydrin is produced. According to a first embodiment of the method according to the invention, the step of contacting is

that cyclodextrin is added to the starting oil-in-water emulsion, then the two compounds are mixed together by moderate agitation for a time t sufficient to allow the formation of cyclodextrin-sterol complexes.

The temperature at which this contact is made is preferably above or equal to 1 ° C, preferably 15 ° C, during t

over or equal to a few seconds and preferably a few minutes.

In addition, it has been found that the cyclodextrin concentration is between 0.01 and 100% by weight, based on the milk fat,

preferably between 1 and 50% by weight and, more desirably, between 2 and 25% by weight.

The mixture of cyclodextrin and oil-in-water starting emulsion is preferably at least one physical Subjected to treatment for the deposition of the complexes formed in water-soluble or water-insoluble form

available.

In order to eliminate these complexes, which are present in water-insoluble form, various treatments can be used

become. It may be centrifuging, decanting, filtering through a membrane or any other method known per se and suitable.

In order to improve the effectiveness of such a treatment, it is according to the invention and preferably appropriate if the Cyclodextrin is present in unpolymerized form to reduce the solubility of the complexes formed by a Temperature is preferably below or equal to 20 ° C, for example at 4 ° C, worked. In this way, the proportion of

insoluble complexes are increased, and their deposition from the liquid phase (s) consequently facilitated.

Centrifugation produces a liquid part and a solid part that forms the sediment. This liquid part consists of

an upwardly floating fat or cream phase from which, at least in part, the sterol cholesterol-cyclodextrin complexes have been extracted due to their low fat affinity, and an aqueous or skim milk phase containing a more or less soluble complex, depending on the processing temperature selected.

Skimmed milk and cream produced in this way can be homogenized to produce reconstituted whole milk

or used separately.

When the selected physical deposition treatment is filtration, the retentate contains the water-insoluble ones Complex, while the filtrate is a non-phase-separated oil-in-water emulsion. The product with reduced content Sterol, and in particular cholesterol, can be used in the dairy industry as a raw material, intermediate or end product. According to an advantageous feature of the invention, the complexes which are in soluble form are replaced by a

physical precipitation treatment of the type ultrafiltration, reverse osmosis or other treatment eliminated.

Such methods are completely mastered by the person skilled in the art. According to the invention they can directly on the Starting emulsion / cyclodextrin mixture, on the aqueous phase (skimmed milk), obtained by centrifugation

or applied to the filtrate formed as the mixture passes through a membrane. They consist of concentrating the substrate concerned by passing it through a selective membrane so that the water and all soluble substances, which are part of the cyclodextrin / cholesterol complexes, are eliminated.

According to a variant of the first application of the method according to the invention, which is somewhat more specific to the Cheese production of the type which has a coagulation step leading to the formation of cheese curds and at least one Extraction stage of the whey such as dripping or pressing, the milk is preferably used as an oil-in-water Starting emulsion used, and it is used a coagulant. This is the milk before and / or simultaneously with and / or after the production of the contact of the milk with the cyclodextrin

added.

This makes it possible, on the one hand, a cheese curd, which can be further processed into cheese in any way, and

on the other hand to obtain whey or an aqueous phase containing all or part of the resulting complexes.

This whey may, in at least one extraction stage, which is incorporated into the cheese production, at least partially from the Cheese curd be deposited. The coagulation of the casein of the milk causes a concentration of the regular lattice, that of the coagulated proteins

is formed and which encloses the fat globules and the whey, with gradual ejection of the latter. These

Apparition is commonly called syneresis. It allows in the context of the method according to the invention Separation of the water-soluble cholesterol / cyclodextrin complexes of the curd. The latter then has the advantage of being particularly low in cholesterol. The coagulant used consists either of at least one acid generator such as glucono-delta-lactone and / or Lactic acid bacterin or from at least one coagulation enzyme of a suitable type such as rennet or both. It is understood that this variant of the method according to the invention to any cheese production of the above

defined type known to those skilled in the art. It does not require any additional equipment and does not significantly increase the production time.

In addition, the addition of cyclodextrin has no adverse effect either qualitatively or quantitatively Effects on manufactured cheeses with reduced cholesterol content. According to a second embodiment of the method according to the invention, the production of the contact of the milk fat takes place

containing oil-in-water starting emulsion with the cyclodextrin and the deposition of the resulting complexes of

Emulsion clearly at the same time and consist in that said starting emulsion by an adsorbent or a

such absorbent is passed, which consists at least partially of cyclodextrin.

It is preferably a column chromatography, advantageously present in polymerized form Beta-cyclodextrin may be used, which may be crosslinked or non-crosslinked, for example by polymerization with Help a bifunctional compound such as epichlorohydrin was prepared. According to a variant, the cyclodextrin can be fixed on a carrier, which consists for example of glass beads. This is

especially in the case when the cyclodextrin is in the form of monomers.

According to an advantageous feature of the invention, the starting oil-in-water emulsion prior to passage to a Temperature between 5 and 60 ⁹ C brought. In the case of milk, this temperature is preferably between 5 and 35 ° C. at In contrast cream, which has a higher viscosity, it is advantageously between 35 and 60 ⁰ C. embodiments

In any event, the invention will be better understood with the aid of the following non-limiting examples of the use of the process for the production of dairy products with reduced sterol content and, in particular, cholesterol to which it relates.

example 1 Producing a cholesterol-poor cream by adding beta-cyclodextrin to the milk. In this example, the starting product is unpasteurized and non-homogenized raw cow's milk. It contains 38g Fat per liter. Powdered beta-cyclodextrin marketed by ROQUETTE FRERES under the registered trademark KLEPTOSE *

is 13.6% water, the whole milk, which was brought to a temperature of about 25 ° C, in a

Amount of 1.0 wt .-%, based on the milk, which are 27 wt .-%, based on the fat added. The whole milk beta-cyclodextrin mixture, maintained at this temperature of 25 ° C, is boiled for about 20 seconds Hand stirred intensely. It is then cooled to 4 ° C, so that the complexes formed at least partially insolubilized

and then centrifuged at this temperature and at 8000 rpm for 20 minutes.

A comparative milk yield without beta-cyclodextrin will be under the same conditions as those just described

cooled and centrifuged.

Before centrifuging, in the case of milk containing no beta-cyclodextrin, there are two distinct phases. The first,

Floating, is the cream. The second, heavier, is the skimmed milk. In the trial with beta-cyclodextrin, a third phase occurs in the form of a solid sediment.

The total cholesterol contained in the supernatant cream and the skimmed milk is determined by gas chromatography

after saponification, extraction of the unsaponifiable fraction and silylation quantitatively determined.

The following results were achieved:

Comparative amount: without addition of β-cyclodextrin

Trial with 1% of the milk added β-cyclodextfin

Cream cholesterol in% floating cream

0.21

0.10

skimmed milk

Cholesterol of skimmed milk in%

3.0 X 10 "

2.1x10 ~ ³

The cream of the milk treated according to the invention with beta-cyclodextrin is low in cholesterol. The rate of reduction

based on the cream of the reference milk quantity of the order of 52%.

The skimmed milk produced by the use of the method according to the invention contains no more cholesterol than

the skimmed comparison milk.

The acid number of the two creams is determined by azimetric filtration in milliliters of potassium hydroxide per 100 grams of fat

measured (method AFNOR T60204). The comparative cream quantity has an acid number of 0.47 after the treatment,

while that of the frame of the experiment is 0.22.

After two weeks of storage in fresh air and at 4 ° C, the comparison cream has an acid number of 1.6 and a

pronounced rancid taste, while the trial has an acid value of 0.90 and a fresh

Creamy taste shows. The improvement of the stability of the latter to oxidation or rancidity is thus

clearly proved.

example Cholesterol content of the supernatant cream as a function of the beta used in the milk Cyclodextrinmengen. In this example, the milk used is the same as used in Example 1. Whole milk is added to increasing amounts of beta-cyclodextrin. The mixtures of whole milk and beta-cyclodextrin are mechanically for 15 minutes and at ambient temperature

slowly stirred. They are then cooled to 4 ° C and at this temperature and at 8000 revolutions per minute

Centrifuged for 20 minutes.

The quantitative determinations of cholesterol are carried out as described in Example 1.

Comparative amount without ß-cyclodextrin

Experiments with ß-cyclodextrin Milk added amounts in%

0.1 0.3 0.6 0.9

Cholesterol in the above floating 0.31 floating creams (in %)

0.18

0.17

0.14

0.10

As the amounts of beta-cyclodextrin added to the milk increase, the cholesterol present in the supernatant cream quantities decreases.

Example 3 Production of a low-cholesterol "whole milk" by reunification of the cream and the skimmed milk, which coincides with the in Example 1 inventive production method described were produced. The cream produced according to the invention after treatment of the raw milk with 1% beta-cyclodextrin is again with the

skimmed milk by 20 sec homogenization at 8000 rpm combined.

The whole milk produced in this way comprises a reference whole milk prepared in the same way

51% reduced cholesterol content. Both milk quantities have an identical pH of 6.90.

In addition, the whole milk produced by the use of the method according to the invention has organoleptic Properties and a physical stability at storage at 5 "C, which are comparable to those of the reference milk quantity As regards the oxidation resistance, it turns out that by application of the invention Process milk produced superior to the comparison milk quantity. Example 4 Preparation of a cream with reduced content of cholesterol by adding polymerized beta-cyclodextrin and Membrane filtration. The cream used in this example is commercial UHT cream containing 35% fat and 0.12% total cholesterol. He

contains 99.98% of the lipids present in the original milk.

The cyclodextrin used is an epichlorohydrin-polymerized beta-cyclodextrin. The cream is heated to 40 ° C. An amount of 2 U wt .-% of polymerized beta-cyclodextrin, equal to 6Gew .-% based on the Amount of fat is added to the cream. The whole is stirred for 10 minutes at this temperature stirred and then

membrane-filtered.

The filtered cream was not destabilized by the addition of cyclodextrin. He has a total cholesterol content of

0.07 wt .-%, which corresponds to a reduction of the cholesterol content by 42%.

Example 5 Preparation of a cholesterol-free whole milk by passing through a column of polymerized beta-cyclodextrin. In this example, the starting milk is a non homogenized and unpasteurized raw milk with a fat content of

37.5g / l, a density of 1.0332 and a total cholesterol content of 21.5mg per 100g.

The cyclodextrin used is an epichlorohydrin-polymerized beta-cyclodextrin. Preparation of polymerized beta-cyclodextrin chromatographic columns:

The polymerized beta-cyclodextrin is hydrated in water at 6 to 10 times its weight. It is then poured into a glass column and washed with deionized water.

Passing the milk through the column: Whole milk brought to a temperature of 20 X is produced in two different types as described above Columns Chromatography. The eluted milk volumes are at least 50 times those contained in the column Cyclodextrin. The determinations of total cholesterol and acid numbers are carried out according to the method described in Example 1.

Starting milk chromatographed milk quantities experiment 1 experiment 2

Total cholesterol 21.5 15.0 14.5

content in mg / 100 g milk

Acid number in 0.45 0.25 0.20

mlKOH / 100gFett

The densities and fat contents of the chromatographed whole milk quantities are very similar to those of the starting milk, ie

1.0332 and 37.3g / l respectively.

The rate of reduction of cholesterol is of the order of 30% and that of the acid number is of the order of In this example, the whole milk is the starting oil-in-water emulsion. Of course, the latter may also be cream. In this case, it is obvious to the person skilled in the art, the passage temperature through the column, taking into account the Increase the risk of clogging for the latter due to the higher viscosity of the cream at ambient temperature. Example 6 Production of curds with reduced content of cholesterol by adding beta-cyclodextrin to the milk and Separation of the resulting complexes during dripping. In this example, the starting emulsion is commercial pasteurized whole milk containing 36.5g of fat per liter and 0.017% Cholesterol, equal to 0.46% cholesterol based on the amount of fat contains. The coagulant used consists of lactic acid bacteria and an enzyme, the lab. In a quantity of 1 liter of milk pure lactic acid bacteria are sown, which develop at low temperatures. At the end of the fermentation, the milk becomes powdered beta-cyclodextrin, obtained from the company ROQUETTE FRERes under the

Trademark KLEPTOSE® is traded and contains 13.6% water, in an amount of 1.0% by weight at one

Temperature of 18-20 ° C was added. The mixture of milk and beta-cyclodextrin is stirred vigorously by hand for about 20 seconds. The rinse is carried out at the same temperature of 18-2O ⁰ C with a quantity of 0.1 to 0.2 ml in a ratio of Vioooo

diluted rennet on 1 liter of milk. After clotting for 24 hours, the curd is drained off so that the whey is eliminated.

A comparative amount of one liter of milk to which no beta-cyclodextrin was added was used to prepare a Cheese breakage processed under the same conditions. The quantitation determinations made according to the method described in Example 1 have the following results

provided:

Experiment with comparative experiment with 1% by weight

Milk volume without the addition of beta-cyclodextrin containing beta-cyclodextrin milk

Cholesterol in%, based on the 0.40 0.19 Fat content of the curd The reduction rate of cholesterol of the curd obtained by use of the method according to the invention

was on the order of 52%.

After two weeks of storing the curds in fresh air and at 4 "C, it has been found that the curd, the

With the addition of beta-cyclodextrin to the milk had become less rancid than the one without addition of

Beta-cyclodextrin had been prepared for milk. It has also been found that the addition of beta-cyclodextrin does not affect the cheese-fitness of the milk. Apart from a slightly reduced strength, the curd made from milk processed according to the invention

was clearly the same characteristics as that produced from the comparison milk quantity.

From the examples described above it is apparent that it is possible with the method according to the invention Dairy products with higher oxidation resistance and a reduced content of sterols, in particular on To produce cholesterol in a particularly easy and economical way. On the basis of initial emulsions such as milk or cream, this process allows, in particular, whole milk, Cream, mainly skimmed milk and cheese that are low in cholesterol. It is clear that these products are intended directly for consumption or for various finished products or Semi-finished products can be further processed. Thus, the cholesterol-free whole milk as basis for the production of yogurt, cheese and cream, which itself again to the Example as a raw material in butter production or in processed or unprocessed form as Food ingredient is suitable, or serve from other. A cholesterol-containing cream produced by the use of the method according to the invention can either be skimmed

Homogenized milk homogenized, which produces reconstituted whole milk, directly consumed or in the production of

Dairy products used or directly consumed as a product or as a starting or intermediate product in the Production of dairy products are used. This list is by no means limiting. Its purpose is to give an indication of the diverse outlets of To give dairy products, which are produced by applying the method according to the invention.

Claims (15)

1. A process for the preparation of dairy products with reduced content of sterols, in particular cholesterol, characterized in that it consists mainly in bringing an oil-in-water emulsion containing milk fats, with cyclodextrin in sufficient amount in contact, the forms inclusion complexes with the sterols, so that the latter can be extracted from the fat and at the same time or not at the same time, at least in part, the said complexes can be separated from the environment, without causing inversion of the starting oil-in-water emulsion. 2. The method according to claim 1, characterized in that the starting oil-in-water emulsion used is milk or cream of any animal origin and of any kind, wherein the fat concentration of the milk is less than or equal to 10% by weight and that of the cream is greater than 10% by weight. -% lies. 3. The method according to claim 1 and 2, characterized in that the cyclodextrin used is of the alpha, beta or gamma type and substituted or unsubstituted. 4. The method according to claim 3, characterized in that the cyclodextrin is crosslinked or uncrosslinked in polymerized form. 5. The method of claim 1 to 4, characterized in that the bringing about of the contact initially consists in that the oil-in-water starting emulsion is mixed with the cyclodextrin in a time t sufficient for the formation of complexes. 6. The method according to claim 5, characterized in that the bringing about of the contact takes place at a temperature above or equal to 1 ⁰ C and preferably at 15 ° C. 7. The method according to claim 5 and 6, characterized in that the cyclodextrin concentration between 0.01 and 100 wt .-%, based on the milk fat, preferably between 1 and 50 wt .-% and more and more useful between 2 and 25Gew. -% lies. 8. The method according to claim 5 to 7, characterized in that the mixture prepared in this way is subjected to at least one physical treatment for the deposition of the complexes formed, which are present in water-soluble or water-insoluble form. A method according to claim 8, characterized in that the physical deposition treatment may be centrifugation, decantation, filtration or other treatment which makes it possible, at least in part, to eliminate the complexes which are in water-insoluble form. A method according to claims 8 and 9, characterized in that the physical deposition treatment can be ultrafiltration, reverse osmosis or other treatment which allows to at least partially eliminate the complexes present in water-soluble form. 11. The method according to claim 9, characterized in that the cyclodextrin used is in polymerized or unpolymerized form and that the physical deposition treatment is carried out at a temperature which is chosen so that the water solubility of the complexes formed is reduced, this temperature preferably is less than or equal to ^20.degree. C., and even more sensibly on the order of 4.degree. A method according to claims 5 to 7, applied to the cheese-making of the type comprising a coagulating step leading to the formation of curd and at least one extraction step of the whey, characterized in that the starting oil-in-water emulsion is preferably milk and that it consists in adding a coagulant to the starting oil-in-water emulsion so that, on the one hand, a curd which can be further processed into cheese and, on the other hand, whey or an aqueous phase, all or one Contains part of the resulting complexes and which can be deposited in the course of an extraction stage of the cheese curd at least partially. 13. The method according to claim 12, characterized in that the coagulant consists of at least one acid generator and / or lactic acid bacteria, which cooperate with at least one coagulation enzyme of suitable type such as Lab or replaced by it. 14. The method according to claim 1 to 4, characterized in that the preparation of the contact and the deposition are carried out significantly simultaneously and consist in that the oil-in-water starting emulsion is passed through an adsorbent or by such adsorbent, at least partially consists of cyclodextrin. 15. The method according to claim 14, characterized in that the cyclodextrin is fixed on a support.