DD292925A5 - PROCESS FOR REDUCING THE CHOLESTERINE CONTENT AND FREE FATS OF ANIMAL FAT AND FAT WON THIS WAY - Google Patents

Abstract

The invention relates to a method for reducing the content of cholesterol and free fatty acids in a fat of animal origin and the fat thus obtained. The method consists in bringing the fat into contact with a cyclodextrin with stirring and in the presence of water, controlling the water / fat weight ratio, the temperature and the stirring so that a fine emulsion of the "OEl-in" Water "type arises dasz then the cyclodextrin-cholesterol complexes thus formed and cyclodextrin-free fatty acid complexes are separated. Fig. 1 {method; Cholesterol; free fatty acid; Fat; cyclodextrin; Cyclodextrin-cholesterol complex}

Description

For this 2 pages drawings

Field of application of the invention

The invention relates to a method for reducing the content of cholesterol and free fatty acids of an animal fat and the fat thus obtained.

Characteristic of the known state of the art

The animal fats, for example the fat of the milk (butter, cream), sebum and lard contain sterols, and in particular cholesterol as well as free fatty acids.

Despite its vital role, cholesterol is considered to be a risk factor in cardiovascular disease, and the growth of atherosclerosis in humans has often been linked to blood cholesterol levels. Consequently, attempts have been made to reduce the amount of cholesterol in the fats used for human consumption. Cholesterol can be removed by evaporation under high vacuum at a temperature between 240 and 280 ° C. However, this treatment results in the loss of natural volatile aromatic substances which also evaporate. By percolating fat at a temperature of 70 to 90 ° C on activated carbon, the cholesterol content can also be reduced, but the activated carbon binds other natural substances of the fodder, especially the aromatic components, the antioxidants and the dye.

Extraction of the cholesteric with carbon dioxide under supercritical conditions, i. at pressures above 100 bar, is an industrially difficult to use process. For example, in the treatment of dairy, a significant proportion of short-chain triglycerides are also deprived

The patent EP-PS O 256911 describes a method for eliminating the cholesterol of animal fats, after which the liquefied fat is brought together with a cyclodextrin, said contact with stirring in a non-oxidizing atmosphere and at a temperature between the melting temperature of the fat and 8O ⁰ C is continued for a period of 30 minutes to 10 hours, during which complexes between the cholesterol and the cyclodextrin are formed, after which water is added and these complexes are extracted from the fat by entrainment in the resulting aqueous phase, which then from the Fat phase is separated. Not only is this process relatively tedious, it also allows only a limited reduction in cholesterol content in a single operation. And in one operation, only 18 to 33% of the original cholesterol can be eliminated. In order to obtain a more substantial extraction, several successive operations must be carried out in this way, which may be followed each time by a washing of the lipid phase. With three successive extractions it is possible to extract 41% of the initial cholesterol. Theoretically, this could eliminate up to 80% of the initial cholesterol. Incidentally, patent EP 0 256 911 does not mention any elimination of the free fatty acids.

Object of the invention

The aim of this invention is to overcome the said drawbacks and to provide a process always based on the extraction of cholesterol of animal fats by cyclodextrin, but designed so that, in a single operation, a rapid and effective reduction of cholesterol content can be achieved At the same time a significant reduction in the content of an animal fat of free fatty acids is achieved. In particular, animal fats are butter, milk cream, anhydrous milk fat, tallow and lard.

Explanation of the essence of the invention

The method according to the invention comprises combining cyclodextrin and fat in the presence of water, then separating the complexes formed between the cyclodextrin and the cholesterol and the fatty acids, and it is essentially characterized in that the weight ratio of water / fat is between 0.4 / 1 and 1.9 / 1, preferably

between 0.7 / 1 and 1.5 / 1, and more favorably about 1/1 is chosen. '

Water is required to form the complexes and, by choosing the weight ratio of water / fat in the ranges mentioned, a very rapid and effective extraction of cholesterol and free fatty acids can be achieved.

The water may be added separately or together with the cyclodextrin. If added separately, this may be done before or after adding the cyclodextrin to the fat. If the water is added after the cyclodextrin, the formation of the complexes may begin even before the addition of the water, but it is slow. Only after the addition of the water, the formation of the complexes is faster and more complete.

For this reason, it is advantageous to add the water at the same time as the cyclodextrin and, in particular, to dissolve the cyclodextrin beforehand in at least one fraction of this water.

Applicant has discovered, and it is an advantageous aspect of the invention, that it was desirable to prepare an oil-in-water type emulsion so that the extraction of cholesterol and free fatty acids would be as effective and rapid as possible.

It appears that the cyclodextrin-cholesterol complexes and the cyclodextrin-free fatty acid complexes are formed at the interface between fat and aqueous solution, and it has been found that surprising and unexpected

This complex formation occurs very rapidly if it is ensured that an emulsion of the type "oil in water" is produced.

The parameters amount of water, stirring and temperature are chosen so that this emulsion forms, aiming to obtain as "fine" as possible, the contacts between the cyclodextrin and the cholesterol and the free fatty acids and thereby their complexation and then their extraction optimally designed.

Since the complexation takes place within the emulsion, the contact time between the cyclodextrin and the fat can be reduced to zero prior to the addition of water, whereas in patent EP-PS 0 256911 this contact time is at least 30 minutes and in practice in the examples given Reached 3 hours.

In the process described in this patent application no "oil-in-water emulsion" is formed, even after the addition of water, since this amount of water is too large, by the way, this amount of water affects the stability of the complexes.

The weight ratio between the amount of water and the amount of fat is therefore very important for obtaining the ideal emulsion of the "oil-in-water type." Incidentally, too small a quantity of water in proportion to the amount of fat causes the formation of an emulsion too viscous and subsequently difficult to break is.

According to one embodiment of the invention, the cyclodextrin is added to the fat in the absence of water and the contact between cyclodextrin and fat in the absence of water is maintained for a period of less than 20 minutes and preferably less than 10 minutes.

According to another embodiment of the invention, the cyclodextrin is previously dissolved in water before being mixed with the fat.

In the case where the fat to which the cholesterol and / or the free fatty acids are to be removed is in the form of an emulsion

is present in water, as in the milk cream of F & >, the cyclodextrin is preferably added in powder form to this emulsion, which is optionally heated to a temperature which facilitates the solubilization of the cyclodextrin in the aqueous phase.

According to an advantageous embodiment of the invention, the temperature of the environment FeU water cyclodextrin is so

At a selected concentration of cyclodextrin, this temperature regulates the solubility temperature of the

Cyclodextrin in water comes close at this concentration. The amount of cyclodextrin used according to the invention is between 1% by weight and 10% by weight in relation to the amount of fat and

preferably between 3Gew .-% and 0Gew .-%. It is generally advantageous to add amounts of cyclodextrin that are 5% higher than the amount of fat used.

Various types of cyclodextrins or of modified cyclodextrins can be used according to the invention, For example, α, β, and γ-cyclodextrin, each containing 6,7 and 8 glucopyranose units, may be mentioned

are interconnected by α-Ι-4 bonds, as well as their respective derivatives such as the hydroxyalkyl cyclodextrins, the

Maltosylcyclodextrins, the glucosylcyclodextrins and the alkylcyclodextrins. Preferably, β-cyclodextrin is used. With a quantity of β-cyclodextrin that is 5% greater than the amount of fat, more than 96%, and even practically 100%, of the Fat contained cholesterol3 can be eliminated using the method according to the invention.

The stirring of the fat-water-cyclodextrin environment must be so strong as to ensure intimate contact between the cyclodextrin and the fat, and according to a preferred embodiment of the invention, the stirring is designed so that the formation of an emulsion of "oil in As already mentioned above, it is desirable to obtain a fine emulsion, the globules of fat distributed in the aqueous phase usually having a size of less than 40 μm, even if some beads whose size can reach 100 μm This allows a very rapid formation of the cyclodextrin-cholesterol complexes and the complexes of cyclodextrin and free fatty acids at the water / fat interface, with intense stirring favoring the contacts ar of this interface aqueous phase, where they become insoluble.The stirring must not be too star shear forces, because experience has shown that these forces cause an increased viscosity of the emulsion, the latter being difficult to break during the later stage of separation of the phases. Appropriate stirring may be achieved, for example, by means of a screw stirrer rotating at high speed, preferably above 800 rpm and in practice at 2000 rpm. Upon proper stirring, there is a change in the appearance of the medium, consisting of fat, water and cyclodextrin. The color changes from a little homogeneous straw yellow color, which contains some whitish stripes, to a uniform milky yellow color.

Thanks to the choice of the weight ratio of water / fat in the above limits and the creation of an oil-in-water emulsion by applying a suitable stirring, excellent results of withdrawal of cholesterol and free fatty acids in a single operation with relatively short contact times and with a utilization rate of the cyclodextrin of 5% relative to the fat can be achieved.

The temperature for preparing the emulsion is also important, and, as already mentioned, it is quite advantageous to set the temperature at a given concentration of cyclodextrin to a value which is relatively close to the solubility temperature of the cyclodextrin in water at that concentration.

If the temperature is too high, the desired emulsion does not form and the formation of the complexes is thereby impaired. If the temperature is too low, there is a risk of recrystallization of the β-cyclodextrin in the aqueous phase prior to formation of the complexes.

After numerous attempts it has been found that the optimum temperature of the medium FeU-water-cyclodextrin is to be sought in the vicinity of the temperature corresponding to the solubility curve of the cyclodextrin in water, and preferably at a value slightly below the solubility temperature of the cyclodextrin in a water selected concentration, so that the phenomenon of hypothermia is taken into account.

Without wishing to be bound by theory, it can be assumed that the regulation of the temperature of the environment to a temperature near the solubility limit of the cyclodextrin, and preferably to a somewhat lower temperature, precipitates or crystallizes the cyclodextrin-cholesterol complexes and the complexes Cyclodextrin and free fatty acids favors.

The choice of the amount of water and the temperature at a given concentration of the cyclodextrin is therefore important to ensure a better effectiveness of the cholesterol withdrawal. It appears that the complexes formed must remain insoluble in the aqueous phase.

The solubility values of the β-cyclodextrin in water as a function of the temperature according to J. SZEJTLI in "Cyclodextrins and Their Inclusion Complexes", Akademiai Kiado, Budapest 1982, are listed in the table below.

Grams of β-cyclodextrin Temperature in ⁰ C in 100 ml of solution 1.20 15 1:48 20 1.79 25 · 2.25 30 3.51 40 4.64 50 6.05 55 7.49 60 10.18 65 12.03 70 14,80 75 19,66 80

and the corresponding solubility curve is shown in FIG.

Calling the solubility temperature of the cyclodextrin T, one can in practice the temperature of the fat-water Select cyclodextrin medium in a range of T -15 ⁰ C to T +15 ⁰ C and preferably T -15 ° C to T + 1O ⁰ C. You will

However, usually choose a temperature that is not more than 5 ° C higher than the said solubility temperature.

With a water-to-fat weight ratio within the specified limits, a suitable stirring and a Emulsion temperature in the above limits of the solubility curve of the cyclodextrin is to be noted that the Formation of the desired fine "oil in water" emulsion occurs almost instantaneously and the complex formation very rapidly

he follows.

However, stirring and thus contact between cyclodexHn, water and fat can be between 1 to 20 minutes and

preferably for about 5 to 10 minutes to ensure that complex formation was substantially complete.

Thanks to the method according to the invention, the contact time between the cyclodextrin, the water and the fat consequently

being very short, and of course this is a significant advantage compared to prior art methods.

Another important advantage lies in the fact that the process is carried out in a normal atmosphere

and that it is not necessary to resort to a non-oxidizing atmosphere, as is the case in the patent

EP-PS 0 256911 described is the case. After complex formation, the aqueous and lipid phases can be separated by any known means, such as centrifuging or Decanting be separated, with the cleaning by centrifugation is preferred. The separation takes place at one above the Melting temperature of the fats lying temperature, and preferably at a temperature that of the complex formation

is relatively close, but preferably slightly lower than this.

Thus, a temperature of about 4O ⁰ C to 45 ⁰ C for an effective separation of the aqueous phase and the fat phase and

the resulting insoluble complexes are chosen.

Preferably, a cooling phase of the mixture of fat, water and cyclodextrin is inserted between the complexing phase and the actual separation stage in order to stabilize the complexes formed by more complete insolubilization. Thus, the mixture in question is first cooled, for example to a temperature of 25 to 35 ° C, preferably about 3O ⁰ C, to complete the insolubilization of the complexes formed, then reheated to the one selected

To reach separation temperature, which, as already mentioned, preferably between 40 and 45 ⁰ C. In view of the presence of insoluble matter in the water, especially of the formed complexes, the separation may occur

advantageously carried out by a centrifuge, which allows frequent removal of precipitation.

These consist mainly of cyclodextrin, which has mainly encapsulated cholesterol and the free fatty acids. The aqueous phase contains a small amount of dry matter consisting essentially of cyclodextrin. The on Cholesterol and free fatty acids poorer fat still contains some water, usually of the order of 0.5%. It can again

heated and treated by vacuum evaporation to bring it to a purity of 99.9%.

After separating the aqueous phase and the fat phase, the fatty phase can be washed with water, whereupon a

renewed separation of the phases thus obtained takes place in the centrifuge.

The separation of the aqueous phase and the fat phase after complex formation can also be achieved by the method of buttering

the cooled emulsion is carried out, with this buttering optionally a melting of the fat and a

Centrifugal cleaning can connect. According to this method, a cooling of the present invention between the fat, the cyclodextrin and the first takes place Water formed emulsion, then allowed to mature for several hours at a temperature of at most 10 ° C, after which Buttering is performed. The aim of the cooling and the physical ripening of the emulsion is to at least partially crystallize the fat, wherein the

partially solid state of the fat is required for the subsequent operation of buttering. This level at lower

Temperature also allows stabilization of the complexes by making them more completely insoluble. The buttering can be done in a traditional dairy butchery (discontinuous churn), but one

continuous buttering machine can also be used.

The emulsion is buttered at low temperature, preferably below about 10 ° C; the recovered fat grains, and before

After all, the buttercorns are then washed and kneaded, then the fat is reduced to its potential

Further processing stored cold. The resulting from this Buttering aqueous phase is low in fat. The resulting in this Kaltbutterungsvorgang grease can then be optionally melted and reheated,

for example, to a temperature of 45 ° C, before being subjected to purification by centrifugation to the

Cyclodextrin residues and the complexes contained therein more completely. As already mentioned above, the fat phase can be washed with water before centrifuging.

It may be noted that if the fat consists of anhydrous milk fat (MGLA) or milk cream, a butter having a reduced content of cholesterol and free fatty acids, which may be marketed in that state, is obtained already after the churning process which, after extraction and evaporation of the water, can be used to produce anhydrous milk fat with reduced levels of cholesterol and free fatty acids.

The process according to the invention can be carried out continuously with the aid of a plant, as shown schematically in FIG This plant contains a dosing device 1 for the ß-cyclodextrin and a dosing device 2 for the water. The

β-cyclodextrin is dissolved in the metered water in the container 3. The solution is introduced into the contact and stirring device 4. Heated fat measured in the dosing apparatus 5 is also supplied to the device 4. The fat phase and aqueous phase leaving the device 4 can be separated in the sludge separator spinner 6. The aqueous phase exits at 7, the complexes at 8 and the fatty phase at 9. The latter phase is reheated in the apparatus 10 and a

Vacuum evaporation in the evaporator 11 subjected. The process can also be partially or completely discontinuous, for example, with the aid of that shown schematically in FIG Plant, which comprises a trough 12 for the preparation of the cyclodextrin solution (BCD), a reaction vessel 13, the

has a double wall in which heated water can circulate, a screw stirrer 14 and a drain cock 15, and a centrifugal separator 6.

To illustrate the invention even more concrete, treatment examples are given below, the one

According to the invention are carried out and the others are listed as a comparison.

In these examples, the following analysis methods were used: To determine cholesterol:

Analysis of sterols by precipitation with digitonin (cholesterol represents 98% of the sterol fraction in anhydrous milk fat (MGLA);

For the determination of free fatty acids:

- Titration of the acidity of MGLA samples dissolved in a neutral mixture of petroleum ether and isopropanol (titration by n-tetrabutyl-hydroxy-ammonium using thymol blue as indicator)

embodiments The invention will be explained in more detail with reference to the following examples. example 1

1 kg anhydrous milk fat (MGLA) of 45 ⁰ C is poured into a glass reaction vessel with a capacity of 5I, which is equipped with a double wall, a variable speed screw stirrer and with a drain cock. Water of 45 ° C flows through the double wall of the stirrer to ensure the thermostating.

To the MGLA is added 50 g (i.e., 5 wt% in terms of fat) of β-cyclodextrin, which is evenly distributed in the lipid phase by stirring. The resulting suspension is stirred for 1 minute.

After this contact time of 1 minute between the MGLA and the ß-cyclodextrin of the suspension is 1 liter of water of 55 ⁰ C was added. The stirring rate is increased to achieve intimate phase mixing and creation of a water-oil interface that is large enough to form the complexes between the cyclodextrin and the cholesterol as well as the free fatty acids and toward the aqueous phase move.

The maximum temperature reached by the mixture is 50 ° C. The phase of contact with stirring and in the presence of water lasts 10 minutes.

Thereafter, the mixture is continuously treated in a centrifugal separator to separate the phases (lipid phase, aqueous phase and β-cyclodextrin that has encapsulated the cholesterol and the free fatty acids). The insoluble complexes settle on the inner wall of the separator and are taken after standstill and opening of the same. The duration of the spin separation is about 8 minutes. Under these separation conditions, the recovered fatty phase contains about 0.2% moisture cassit. Vacuum evaporation makes it possible to reduce this moisture content to below 0.1%. No additional washing of the recovered MGLA was performed. From Example 14 below, it can be seen that this washing process is not really indispensable in terms of cleaning quality.

Examples 2 to β The conditions used in these examples are identical to those of Example 1, except for the contact time

between the MGLA and the β-cyclodextrin, each increased to 5 minutes, 10 minutes, 20 minutes, 40 minutes and 120 minutes.

The results obtained with respect to the contents of cholesterol and free fatty acids before and after the treatment are in the

summarized in Table I below.

It should be noted that at this weight ratio water / fat = 1/1 and at a contact time of only 10 minutes at Presence of water can be achieved very satisfactory reduction rates of cholesterol content, as this approximately

Can reach 70%.

The percentage of reduction in free fatty acids is about 30 to 40%. Table I

Bei- H ₂ O /

play MGLA

No.

Time Time% Cholesterol without initial content% Re- initial water Content after handling content (min) (min) treatment

% Fatty acids content

after treatment

% Reduction

1 1.1 1 10 0.31 0.11 65 0.24 0.15 38 2 1.1 5 10 0.31 0.09 71 0.24 0.15 38 3 1.1 10 10 0.31 0.10 68 0.24 0.16 33 4 1.1 20 10 0.31 0.13 58 0.24 0.16 33 5 1.1 40 10 0.31 0.13 58 0.24 0.15 38 6 1.1 120 10 0.29 0.13 55 0.21 0.16 24 7 2.1 10 10 0.31 0.23 26 0.24 0.17 29 8th 3.1 10 10 0.31 0.26 16 0.24 0.18 25 9 4.1 10 10 0.31 0.28 10 0.24 0.18 25 10 1.5 10 10 0.31 0.27 13 0.24 0.19 21 11 1.6 10 10 0.31 0.27 13 0.24 0.18 25 12 1.10 10 10 0.29 0.27 7 0.21 0.16 24 13 1.1 10 10 0.27 0.19 30 0.16 0.15 6 14 1.1 5 10 0.27 0.08 70 nb nb nb

nb: not determined

This series of experiments also shows that the contact time between cyclodextrin and fat in the absence of water has very little influence on the results obtained, since it can be seen that at very short times of 1 minute to 5 minutes, the reduction rates already reached are 65 to 71% , It even appears that longer contact times tend to be detrimental to the withdrawal of cholesterol and free fatty acids. This example, of course, must be compared with the examples of patent application EP 0256911, according to which in one operation a cholesterol elimination result of only 26% is obtained after 3 hours of contact between the cyclodextrin and the fat in the absence of water to which contact for 3 hours with stirring in the presence of water, wherein the weight ratio of water / MGLA is 10/1.

Examples 7 to 12 ·

These examples are intended to demonstrate the influence of the weight ratio of water / MGLA. Examples 1 to 6 were carried out with a weight ratio of water / MGLA of 1/1. The following examples

show the negative influence of too high a water / MGLA weight ratio.

The experimental conditions are the same as in Example 3, d. H. a contact time between β-cyclodextrin and MGLA of

10 minutes in the absence of water, a percentage of 5% by weight of cyclodextrin with respect to the fat, a contact time with stirring in the presence of water of 10 minutes, a temperature of the mixture of about 50 ° C. The quantities of water

and MGLA containing 5% β-cyclodextrin were the following in each Example: Example 7: 2 kg water to 1 kg MGLA containing 50 g cyclodextrin Example 8: 3 kg water to 1 kg MGLA containing 50 g β-cyclodextrin Example 9: 2kg water to 0.5kg MGLA containing 25g β-cyclodextrin

Example 10: 2.5kg water to 0.5kg MGLA containing 25g β-cyclodextrin Example 11: 3kg water to 0.5kg MGLA containing 25g β-cyclodextrin Example 12: 3kg water to 0.3kg MGLA, the Contains 15 g ß-cyclodextrin.

The results obtained in Examples 7 to 12 are shown in Table I. It should be noted that under otherwise identical conditions, the weight ratio of water / MGLA a tremendous impact on the

has achieved withdrawal results. Namely, the reduction percentage of cholesterol falls from 68% in Example 3 to one

H ₂ O / MGLA ratio of 1/1 to 26% in Example 7, where this ratio was increased to 2/1. Reduction percentage

Cholesterol decreases as the water / fat ratio increases.

The course appears to be less susceptible to the reduction percentage of the free fatty acids, but the optimum is

also achieved here at a water / fat ratio of about 1/1.

Example 13 The experimental conditions are the same as in Example 2, except for the way the phases are separated by here Decant and not by centrifugal separation, with this decantation three washes with 1 kg Add water at 55 ^° C for each wash. The washing operations are applied to a maximum

Complexed ß-cyclodextrin, since the amount of residual water in the decanted fat phase is significantly greater than in the case of centrifugal separation (about 15% in 10 minutes for decantation versus 0.2% for centrifugation).

After the last wash, the fat phase is finally treated by vacuum evaporation to add the last water fraction

remove.

The result obtained for the withdrawal of cholesterol and the free fatty acids is also shown in Table I. Example 14

The conditions are the same as in Example 3, except for carrying out an additional washing with 1 kg of water at 55 ⁰ C after the centrifugal separation of the phases. The wash water is separated from the purified MGLA (anhydrous milk fat) by another centrifugal separation. The results obtained are also included in Table I. It should be noted that in this case, the additional washing hardly brings about an improvement in the withdrawal rate of cholesterol.

Example 15 The conditions are the same as in Example 1, apart from the fact that the MGLA a temperature of 35 ⁰ C

has and the 1 900cm ³ of water at 35 ° C added to the MGLA-cyclodextrin mixture.

The maximum temperature reached by the mixture is 35 ° C, and the contact phase with stirring and in the presence of Water takes 10 minutes. The separation by centrifugation is carried out under the same conditions as in Example 1, and gives a Cholesterol reduction rate of 54%. This example shows that by influencing the production temperature of the Grease-water-cyclodextrin mixture even with such high water / fat weight ratios achievable results

can be. To the extent that the temperature of the gomish can be lowered even further, taking into account in particular the solidification temperature of the treated product, the invention in an advantageous embodiment allows the water / fat ratio to be increased to more than 1.9, even more increase as 2.

Examples 16 to 31 Examples 16 to 31 were carried out with the aid of the system schematically illustrated in FIG. An amount of β-cyclodextrin is dissolved in 1.5 kg of water in the container 12. MGLA in the same amount as the amount of water is added to the reaction vessel 13, if it is not already

was previously liquefied by heated water circulating in the double wall of the container 13.

The β-cyclodextrin solution is mixed with liquefied MGLA and the mixture is passed through a propeller mixer 14, the

is eccentrically installed in the container 13 and rotates at a speed of 2000U / min, stirred vigorously. The contents of the container 13, d. H. the resulting emulsion is kept at a temperature which is heated by the heated, in dor

Double wall of the container 13 circulating water is determined. After about 10 minutes of mixing, the container 13 is emptied via the drain cock 15, and the aqueous phase and the fatty phase

are separated in a centrifuging machine 6. Since these examples are laboratory-scale experiments, centrifugal separation can be carried out with the aid of a skimming centrifuge type ALFA-LAVAL100 AE. On an industrial scale, centrifugal cleaning can be used. All this is repeated at varying amounts of β-cyclodextrin and at different emulsion temperatures.

These β-cyclodaxtrin levels and these temperatures as well as the results obtained for the withdrawal of the cholesterol and the free fatty acids are summarized in Table II below.

The different conditions with regard to the temperature and the β-cyclodextrin content in Examples 16 to 31 were also indicated in FIG.

From these examples, it is clear that a very significant reduction in cholesterol and free fatty acid levels is achieved when, for a given amount of β-cyclodextrin, the temperature approaches the solubility curve and also when the β-cyclodextrin level is 5% higher than the fat level ,

In Examples 18 and 29, the fine "oil in water" emulsion did not form, giving rise to the negative results obtained

result.

In Examples 16, 19 to 22 and 26, where the temperatures chosen are the solubility temperature of the β-cyclodextrin

Nearly all cholesterol was withdrawn.

Also good results are achieved when the temperature is slightly above the Lösüchkeitstemperatur, as in the Examples 20 and 23, but it is found that it is better to choose a temperature slightly below that Solubility temperature of the cyclodextrin is. Examples 32 to 35

Analogous experiments with refined beef fat and refined lard are used instead of anhydrous milk fat (MGLA) with the same equipment as that used in Examples 16 to 31.

The experimental conditions and the results of the extractions are shown below in Table IV for lard

played.

It can be said that the results are quite conclusive, both in terms of withdrawal of cholesterol and

also the withdrawal of free fatty acids.

Examples 36 to 38 In addition to the experiments carried out with pure fats (MGLA, beef fat and lard), there were also successful ones Try with fresh milk cream. The fresh milk cream has the following average composition:

- Water: 54.8% - Fat: 40.0% - lactose: 2.8% - Proteins: 2.0% - Ash: 0.4%

In Example 36, the milk cream was first concentrated to 50% fat content to maintain the experimental baths in terms of the amount of aqueous phase; this concentration was performed by skimming at 55 ⁰ C in the Laborentrahmungszentrifuge ALFA-LAVAL 100 AE

After this de-creaming, the cream with a fat content of 60% was made into powdered β-cyclodextrin for a content of 3.5% in the cream (ie 7% in terms of fat or 6.54 "/" in terms of aqueous phase including the .beta.-cyclodextrin). This addition to the cream is carried out at 55 ⁰ C cream temperature. Then the cream is cooled to 5O ⁰ C in the reaction vessel and stirred at 2000 / min.

After about 10 minutes of mixing, the cream was concentrated to 70% fat by a fresh pass through the laboratory centrifuge. A deposition of complex-bound β-cyclodextrin was carried out on the inner wall of the centrifuge drum.

Finally, the thus treated cream was cooled to 70% fat, ripened in a refrigerator overnight and buttered.

The fat of the butter obtained by this buttering was subjected to an analysis of the sterols and free fatty acids. The results of the removal of these compounds of fat are excellent, as shown in Tables V and Vl below

show included results.

In Example 37, 3 kg of 38% fat milk cream is added directly to 79.8 g of β-cyclodextrin (i.e., 7% expressed in terms of fat or 4.11% expressed in terms of aqueous phase including β-cyclodextrin). This addition takes place in the

Cream of 55 ⁰ C.

After that, the cream is cooled to 5O ⁰ C in the reaction vessel and stirred at 2000 U / min.

After lOminütigem mixing at 5O ⁰ C, the cream was up to a temperature below 1O ⁰ C cooled by a

Tube heat exchanger went through.

Tables Ex. MGLA No. (kg)

Water BCD (kg) solution (kg)

BCD / MGLA% BCD Temp.

in% in-water Emul.

riger ( ⁰ C)

solution

cholesterol

% before% after% re-treatment. Trt. duzierung

Free fatty acids% before% after% Re-Dehandl. Trt. duzierung

16 1.5 1.5 (Kg) 0,150 10 9.09 60 0,302 0,006 98 0,030 tion cholesterol % Re 0.36 I %in front 0.20 44 0.05 tion %in front % to %Re- 17 1.5 1.5 0,150 10 9.09 70 0.304 0,040 87 0,018 72 %to duzie 0.26 0.14 46 0.03 44 Trt. Trt .duzie- 18 1.5 1.5 0,150 10 9.09 75 0.293 0,262 11 83 Trt. tion 0.29 0.27 7 67 tion 19 1.5 1.5 0,120 8th 7.41 58 0.304 0,000 100 0.26 0.12 54 20 1.5 1.5 0,120 8th 7.41 63 0.304, , 0.025 92 0.26 0.13 50 Free fatty acids 2 ', 1.5 1.5 0.105 7 6.54 50 0,258 0,004 98 0.19 0.08 58 22 1.5 1.5 0.105 7 6.54 54 0,258 0,003 99 0.19 0.10 47 23 1.5 1.5 0.105 7 6.54 60 0.304 0.063 79 0.26 0.15 42 24 1.5 1.5 0.105 7 6.54 70 0.304 0,119 61 0.26 0.18 31 25 1.5 1.5 0,090 6 5.66 45 0,258 0,060 77 0.19 0.09 53 26 1.5 1.5 0,090 6 5.66 50 0.303 0,013 96 0.24 0.12 50 27 1.5 1.5 0,075 5 4.76 40 0,258 0.079 69 0.19 0.08 58 28 1.5 1.5 0,075 5 4.76 45 0.333 0,080 76 0.37 0.24 35 29 1.5 1.5 0,075 5 4.76 70 0279 0.244 13 0.24 0.20 17 30 1.5 1.5 0,060 4 3.85 35 0,258 0,117 55 0.19 0.08 58 31 1.5 1.5 0,045 3 2.91 35 0,258 0.164 37 0.19 0.14 26 table III Ex. swot up water BCD BCD / fat BCD% Temp. cholesterol ^F ree fatty acids No. fat (Kg) Del. in% in aq Emuls. %in front % to % to% Re (Kg) (Kg) engined ( ⁰ C) ι% Re- Trt. Trt. duzie- solution Trt. Trt. duzie- 32 1.5 1.5 0,075 5 4.76 45 0.09 33 1.5 1.5 0.105 7 6.54 55 0.108 0.09 Table IV 0.108 Ex. Lard water BCD BCD / fat BCD% Temp. No. (Kg) Del. in% in aq Emuls. (Kg) engined ( ⁰ C) %in front solution Trt.

1.5 1.5

1.5 1.5

0.075 0.105

4.76 6.54

45 55

0.036 0.026

66 75

0.06 0.06

0.04 0.03

33 50

This treated cream was finally buttered in the refrigerator after one night of ripening. The experimental conditions as well as the results of the analysis of the sterols (cholesterol) and the fatty acids of the fat of the butter obtained by this churning are given in Tables V and VI.

In Example 38, 3kg milk cream with a fat content of 42.4% was added directly to 63.5 g β-cyclodextrin (namely 5% expressed in fat or 3.54% expressed in aqueous phase including β-cyclodextrin). This addition takes place in the cream of 55 ° C

Thereafter, the cream in the reaction vessel is cooled to 45 ° C and stirred at 2000 rpm.

After 10 minutes of mixing at 45 ⁰ C, the cream was cooled to a temperature below 1O ⁰ C by passing oinos tubular exchanger.

After one night of ripening in the refrigerator and frying the cream, the results of withdrawal of the cholesterol and free fatty acids contained in Table VI were obtained from the fat of the butter resulting from the buttering. The experimental conditions are listed in Table V.

Example 39

This example illustrates the withdrawal of cholesterol and free fatty acids from the anhydrous milk fat (MGLA), in a continuous manner and with equipment as shown in FIG.

The separation of the fat phase and the aqueous phase was in this case by centrifugation.

MGLA, which has a fat content above 99%, is the container 5, which kept at 40 ⁰ C by circulation of hot water

is fed at a rate of 1500 kg per hour.

Table V

Ex.

Cream (kg)

% Fat of the cream

(Kg)

Clogged

BCD / cream

β-cyclodextrin BCD / fat

BCD / aqueous phase temperature with mixture

BCD in% ("C)

36 3.0 50 0.105 3.5 7 6.54 50 37 3.0 38 .0798 2.67 7 4.11 50 38 3.0 42.4 0.0635 2.12 5 3.54 45 Table VI cholesterol fatty acids Ex. %in front % to% reduction %in front % to% reduction No. Beh. Beh. Beh. Beh.

0,288

0.290 0.300

0.009

0.008 0.023

97 97 92

0.10

0.04 0.11

71

84 54

In parallel, the β-cyclodextrin solution is prepared continuously and with stirring in the dissolution tank 3. The water was fed to this vessel continuously at a rate of 1500kg per hour by means of a pump controlled by a mass flow meter. The powdery β-cyclodextrin is continuously added through a powder distributor in this container 3, the mass flow rate is set to 105 kg per hour. The dissolution of the β-cyclodextrin takes place at 65 ^° C. for about 6 minutes.

An oil-in-water emulsion of the MGLA (anhydrous milk fat) and the aqueous β-cyclodextrin solution is then prepared continuously and with stirring in the emulsion container 4. For this purpose, the MGLA of 40 ⁰ C is continuously introduced at a rate of 1500 kg per hour in the container 4, and the aqueous β-cyclodextrin solution of 65 ° C is added in an amount of 1605kg per hour in the same container, the flow rates are regulated by means of pumps which are controlled by mass flow meters. The emulsion is formed by stirring at a temperature of 55 ⁰ C, and the average residence time in the container is about 3 minutes.

The emulsion is pumped with a positive pump into the emulsion tank 4 whose power is set to the sum of the throughputs of MGLA and aqueous beta-cyclodextrin, and d <j emulsion passes through a first plate heat exchanger where it of 55 ⁰ C to a temperature of is cooled below 30 ° C. This cooling serves to stabilize the complexes by further rendering them insoluble. The emulsion then flows around the second plate heat exchanger where it is heated to 42 ⁰ C, that is, which is to a temperature between the melting point of the fat, and the production temperature of the emulsion. The emulsion containing about 50% fat is then destabilized in a first centrifugal concentrator which concentrates the lipid phase to about 80%. The practically no fat-containing aqueous phase is not recycled. The insoluble phase, ie the complexes formed settle in the drum of the machine and this deposit is discharged at regular intervals through the drum opening. The approximately 80% fat-containing lipid phase is pumped to a first centrifuge, where it is concentrated to about 99.2%. Another, lesser precipitate of the insoluble phase forms in the drum of this second centrifuge. This deposit is also discharged at regular intervals through the drum opening. The trapped aqueous phase contains about 30% fat and this phase can be concentrated to about 75% fat in a second concentrating centrifuge to be recycled prior to the first centrifuge. The fat phase is finally concentrated by treatment in the vacuum evaporator 11 to 99.9% fat content. This operation is performed at 75 ⁰ C under a vacuum of ± 20 Torr, and produces a MGLA with a reduced content of cholesterol and free fatty acids, because the rate of reduction of the cholesterol under these conditions reaches more than 85%.

Example 40

This example is identical to the previous one, except that the separation of the aqueous phase and the lipid phase is now carried out by buttering with subsequent centrifugal purification.

After leaving the container No. 4, the emulsion is fed to a heat exchanger, where it is cooled, then the

cold emulsion in a container for physical ripening, where it lingers for 12 hours at a temperature below 1O ⁰ C.

After this physical ripening, whose goal is the crystallization of the fat and the stabilization of the complexes, the

celte emulsion supplied to the churn, which in the present case a classic dairy butter finisher (discontinuous

Butterfertiger) is. The emulsion is buttered at a temperature of 10 ° C. The obtained buttercorn is then washed and

kneaded. The butter is stored cold before further treatment. The resulting from this Buttering aqueous phase is low in fat.

The "butter", which contains about 80% fat, is then melted and heated in a grid-fired kettle, and the Temperature of the butter is stabilized at about 45 ⁰ C. The melted butter, containing 70 to 80% milk fat, is then pumped to a first centrifuge, where the Lipid phase is concentrated to about 99.2% fat. A precipitate of the insoluble phase is formed in the centrifuge drum

and is discharged at regular intervals from the drum opening. The trapped aqueous phase contains about 30% fat and can be concentrated in a centrifuge concentrator to about 75% fat to recycle prior to the first purifier.

The lipid phase can then be evaporated under vacuum under the same conditions as in the previous example,

to gain 99.9% MQLA fat with reduced levels of cholesterol and free fatty acids. The percentage of cholesterol reduction under these conditions is more than 85%.

Example 41 In this example, a continuous operation is described starting from dairy cream with 40% fat content Separation of the phases by centrifuge cleaning takes place.

The cold cream to be treated is first heated to 65 ^° C. in a plate heat exchanger and then fed to the processing line via a buffer tank.

The dissolution of the β-cyclodextrin in the aqueous phase of the warm cream is carried out continuously and with stirring in the dissolution vessel 3.

The cream is continuously introduced into this container at a rate of about 3000 kg / hour with a pump controlled by a mass flow meter. The powdery β-cyclodextrin is continuously added by means of a powder distributor in the same container, the amount is set to 64 kg / hour. The dissolution of the β-cyclodextrin takes place at 65 ^° C. for about 3 minutes.

The β-cyclodextrin-containing cream is then cooled to 55 ^° C. in a plate heat exchanger and is then fed continuously through a pump controlled by a mass flowmeter to the emulsion container where it remains for about 3 minutes with stirring. Thanks to these temperature, time and stirring conditions, the β-cyclodextrin complexes can form.

The emulsified cream is then pumped from the emulsion container 4 by means of a positive pump whose output is adjusted to the delivery rate of the feed pump of the emulsion container. The cream passes through a first plate heat exchanger, where it is cooled from 55 ⁰ C to a temperature below 3O ⁰ C, then it passes through a second plate heat exchanger, where it is reheated to 55 ⁰ C. The emulsified cream, containing about 40% milk fat, is fed to a first centrifugal concentrator which concentrates the lipid phase to about 80%. The aqueous phase or buttermilk is collected at the water outlet of the concentrator and contains very little fat. This aqueous phase is not recycled to the processing line. The insoluble phase, ie the complexes, form a precipitate in the centrifuge drum, which is discharged at regular intervals by opening the drum. The cream's lipid phase, which contains about 80% milk fat, was not destabilized in the first centrifugal concentrator and is still in the form of a creamy emulsion. Inverting the phases is realized and the concentrated and inverted emulsion becomes one A reduced precipitate of the insoluble phase forms in the drum and is discharged at regular intervals through the orifice of the bottom The collected aqueous phase or buttermilk, which contains about 30% fat, is pumped out. is concentrated to 75% fat content with the aid of a second centrifuge concentrator and is recycled prior to the first centrifuge The fat phase is then concentrated to 99.9% fat by treatment in a vacuum evaporator, this process taking place under the same conditions as in the previous ones Examples: An anhydrous milk fat is thus obtained (M GLA) with a very low content of cholesterol and free fatty acids. The percentage of cholesterol reduction in this case is more than 85%.

Claims (11)

claims: 1. A method for reducing the content of cholesterol and free fatty acids of an animal fat, characterized in that the fat with the cyclodextrin with stirring and in the presence of such an amount of water that the water-fat ratio between 0.4 / 1 and 1 9/1, preferably between 0.7 / 1 and 1.5 / 1 and even more favorably at 1/1, is brought into contact, that then the complexes are separated, which are between the cyclodextrin and the cholesterol and the free Have formed fatty acids. 2. The method according to claim 1, characterized in that the stirring conditions are controlled so that an emulsion of the "oil in water" type is formed. 3. The method according to claim 2, characterized in that the stirring is carried out by means of a stirrer that rotates at high speed, preferably at a speed of more than 800 U / min and advantageously of approximately 2000 U / min. 4. The method according to claim 1 to 3, characterized in that the cyclodextrin is added in an amount which is between 1 to 10 wt .-%, and preferably between 3 and 8Gew .-% in relation to the amount of fat. 5. The method of claim 1 to 4, characterized in that the temperature of the fat-water-cyclodextrin environment at a given concentration of the cyclodextrin is regulated to a value which is relatively close to the solubility temperature of the cyclodextrin in water at this concentration. 6. The method according to claim 1 to 5, characterized in that the contact between the fat, the cyclodextrin and water is maintained long enough to ensure the complex formation, and preferably for a period of 1 to 20 minutes. 7. The method according to claim 1 to 6, characterized in that the step of separation takes place by centrifugal cleaning. 8. The method according to claim 1 to 7, characterized in that the separation step takes place at a temperature which is below that selected for the complex formation. 9. The method according to claim 1 to 8, characterized in that the separation of the aqueous and the lipid phase after formation of the complexes by cold-buttering the water-cyclodextrin-fat emulsion. 10. The method according to claim 1 to 9, characterized in that the cyclodextrin used is β-cyclodextrin. 11. A method for reducing the content of cholesterol and free fatty acids in an animal fat, characterized in that the fat is brought together with a 3m cyclodextrin with stirring and in the presence of water, wherein the weight ratio water / fat, the temperature and the stirring be chosen so that an emulsion of the type "oil in water" is formed, that then the complexes are separated, which have formed between the cyclodextrin and the cholesterol and the free fatty acids.