EP3555254A2

EP3555254A2 - Two-dimensional fractionation of milk fat

Info

Publication number: EP3555254A2
Application number: EP17825810.9A
Authority: EP
Inventors: Franciscus Johannes Gerardus Boerboom; William Kloek; Cynthia Akkermans; Reza RANJBAR DAVIJANI; Michiel Scheffer
Original assignee: FrieslandCampina Nederland BV
Current assignee: FrieslandCampina Nederland BV
Priority date: 2016-12-15
Filing date: 2017-12-15
Publication date: 2019-10-23
Also published as: WO2018109203A2; WO2018109203A3; CN110072984A

Abstract

The invention relates to a process for preparing a fat fractionate, comprising providing an intermediate fat fraction of a starting material selected from the group consisting of milk fats and fat mixtures of milk fat and at least one other fat, which fat mixtures are composed of more than 50 wt. % milk fat, preferably at least 90 wt. % milk fat - said starting material preferably being anhydrous - by a dry fractionation; and subjecting said intermediate fat fraction to a supercritical fluid fractionation, wherein the fat fractionate is obtained as a raffinate of the supercritical fluid fractionation or as a distillate of the supercritical fluid fractionation, optionally after removing the supercritical fluid.

Description

Title: Two-dimensional fractionation of milk fat

The invention relates to a process for preparing a fat fractionate from a fat composition comprising milk fat. Further, the invention relates to a fat fraction. Further, the invention relates to a method for preparing a food product, comprising the use a fat fractionate according to the invention.

Milk fat is complex mixture of triglycerides and other lipid components. Milk fat typically consists for the largest part of triglycerides (e.g. about 98 %). The triglycerides generally have a carbon number in the range of 26-54. In particular for milk fat from cow milk, usually, the carbon number distribution is bimodal, i.e. milk fat has fatty acids with a relatively high content of relatively small acyl groups (4-6 carbons), a relatively high content of relatively large acyl groups (at least 14 carbons) and a relatively low content of acyl groups of intermediate length (8- 12 carbons), In addition to triglycerides, milk fat typically contains several minor components, such as cholesterol, fat-soluble vitamins, free fatty acids, monoglycerides, diglycerides and various other organic components, such as lactones, ketones and aldehydes, contributing to the characteristic flavour or aroma of milk fat.

The flavour of milk fat is a much appreciated asset of this product. Also, milk fat contains various highly nutritious components. However, not all ingredients of milk fat are appreciated for their nutritional value. Furthermore, milk fat has characteristic physical properties, e.g. melting range and structural functionalities, e.g. consistency, spreadability and the like. Such properties are desirable for specific applications, but not necessarily so for others. For example, milk fat may be used as a substitute for cocoa-butter in chocolate products or chocolate imitation products (compounds). However, increasing incorporation of milk fat in such products may cause undesirable softening, changes in tempering conditions, gloss or contraction.

In order to enhance the utilization of milk fat as a fat source, several processes have been developed to recover a milk fat fraction with improved physical and/or nutritional properties (See, e.g., 'Trends in edible oil fractionation,

W. Hamm, Trends in Food Science & Technology April 1995 Vol 6, pl21-12ff,

'By strom and Hartel , Lebensm-Wiss u-Technol. 27, 142-150 (1994J and 'Solubility of milk fat triglycerides in supercritical carbon dioxide, J. Arul et al, Food Research International 27 (1994) _P459-46T).

An example of such a process is interesterification. This process is primarily used to shift the acyl groups attached to the sn: l, sn:2 and sn:3 position of the triglycerides. Short path distillation or solvent fractionation can also be used as methods to obtain milk fat products with altered properties.

A common process is milk fat fractionation on the basis of melt temperature (dry fractionation, also known as melt crystallisation). This process can be a single-step fractionation or a multi-step fractionation. In each

fractionation step a liquid phase (marked as '0' for Olein', because this fraction typically is enriched in oleic acid (bound as triglyceride), indicative of long-chain unsaturated fatty acid content) and a solid phase (marked as 'S' for 'stearin' because this fraction typically is enriched in stearic acid (bound as triglyceride), indicative of long-chain fatty acid content). In a multi-step process at least one of the fractions obtained in a previous fractionation step is subjected to at least one further fractionation, resulting in further fluid fraction and a further solid fraction. The obtained fractions can be named on the basis of the subsequent fractions from which the final fat fraction is obtained (see Deffense, E.M.J. (1987), Fat Sci.

Technol. , 89, 502—507). Thus, SO is the fluid fraction obtained after the dry fractionating the solid fraction from a first dry fractionation step, whereas SS would be the solid fraction after that second fractionation step. As another example: OOO is the fluid fraction of a triple dry fractionation process wherein the liquid phase of a first fractionation (O) was subjected to a second dry fractionation step and the liquid phase of the second fractionation (00) was subjected to a third fractionation. OOS would then be the solid fraction of that third fractionation.

Dry fractionation is for instance used to produce butter having superior spreading properties and the production of milk fat fractions for use in bakery applications. It has also been proposed to use a solid fraction of a dry fractionation process in the production of chocolate products, for instance to replace cocoa butter or to change the texture of chocolate but so far literature shows that this has not yet been successful.

Supercritical fluid fractionation (also known as supercritical fluid extraction of liquids) has been proposed as an alternative to dry fractionation (see also the above identified review by Hamm and paper by Arul et al). With this process a raffinate and a distillate is obtained. Supercritical fluid fractionation is thought to fractionate fats primarily on the basis of molecular weight.

EP 74145 Al is an example of a patent application relating to a process wherein supercritical fluid fractionation is used to produce a mixture of triglycerides having butter-like properties. However, the ratio

saturated/unsaturated acyl groups in the fractions can also be altered in a different way than this ratio is altered in dry fractionation.

Conventionally employed supercritical fluid fractionation of milk fat is considered not competitive with dry fractionation in terms of capital and operational costs.

Further, the above mentioned paper by Bystrom and Hartel discusses the utilisation of mteresterified milk fat fractions or milk fat fractions obtained by either dry fractionation or supercritical fluid fractionation. This paper illustrates that neither dry fractionation nor supercritical fluid fractionation are fully satisfactory to provide a substitute for cacao butter, and that supercritical fluid fractionation may result in a worse product than dry fractionation for this application.

Further, a drawback of supercritical fluid extraction is a potential loss of aroma components.

Thus, there is a continued need for alternative processes that can be used to obtain fat compositions, at least majorly based on milk fat, having specific properties, such as a nutritional value, specific structural properties, specific flavour/aroma properties and the like, as desired for a particular application. In particular there is a need for alternative fat compositions, based at least majorly on milk fat. For instance, there is a need for fat compositions that more closely resemble mother milk than conventional milk fat fractions. Such compositions are particularly interesting for formulating infant formulas and toddler food products.

Also, there is a need for alternative fat compositions for use in other food applications, such as bakery applications, confectionary applications, chocolate (compounds) applications, health food applications etc..

Further, a need exists for alternative flavouring/aroma compositions, based on milk fat. Further, there is a need for alternative fat compositions that are regarded as having a highly nutritional value (e.g. high content of mono- or polyunsaturated fatty acids), yet have another property that is generally thought to be associated with fat components considered less healthy, such as high melting point.

In particular, there is a need to provide a process having an improved efficiency compared to either dry fractionation or supercritical fractionation, for instance with respect to obtaining a fat fractionate enriched in one or more components of interest and depleted in one or more undesired components.

The inventors have now found that a specific combination of two distinct fractionation techniques is suitable to provide in a need as indicated herein above or elsewhere in the present description.

Accordingly, the invention relates to a process for preparing a fat fractionate, comprising

- providing an intermediate fat fraction of a starting material selected from the group consisting of milk fats and fat mixtures of milk fat and at least one other fat, which fat mixtures are composed of more than 50 wt. % milk fat, preferably at least 90 wt. % milk fat - said starting material preferably being anhydrous - by a dry fractionation; and

- subjecting said intermediate fat fraction to a supercritical fluid fractionation, wherein the fat fractionate is obtained as a raffinate of the supercritical fluid fractionation or as a distillate of the supercritical fluid fractionation, optionally after removing the supercritical fluid.

Further, the invention relates to a process for preparing a fat fractionate, comprising

providing an intermediate fat fraction of a starting material selected from the group consisting of milk fats and fat mixtures of milk fat and at least one other fat, which fat mixtures are composed of more than 50 wt. % milk fat, preferably at least 90 wt. % milk fat - said starting material preferably being anhydrous -by a supercritical fluid fractionation; and

subjecting said intermediate fat fraction to a single-step or multi-step dry fractionation, wherein the fat fractionate is obtained as a fluid fraction or as a solid fraction of the dry fractionation. The invention further relates to a fat fraction obtainable as a fat fractionate by a process according to the invention.

The invention further relates to a method for making a food product, comprising combining a fat fractionate prepared by a process according to the invention or a fat fraction according to the invention with one or more further (usual) food ingredients for making said food product.

As illustrated in the Examples, a process according to the invention is suitable to obtain fat fractions that are different from the starting material and from the intermediate fat fraction in one or more of the following aspects:

concentration of one or more specific or the total of saturated fatty acids (SAFA); concentration of one or more specific or the total of monounsaturated fatty acids (MUFA); concentration of one or more specific or the total of polyunsaturated fatty acids (PUFA); concentration of n3-polyunsaturated fatty acids; concentration of n3- polyunsaturated fatty acids; concentration of one or more fat-soluble vitamins, such as a fat-soluble vitamin selected from the group of vitamin A, vitamin E, vitamin Kl and vitamin K2; concentration of cholesterol; concentration of one or more specific or total lactones; concentration of one or more specific or total ketones; concentration of one or more specific or total aldehydes; concentration of total short-chain fatty acids (C4-C6, abbreviated as SCFA); concentration of total medium-chain fatty acids (C8-C12, abbreviated as MCFA); concentration of total long-chain fatty acids (C14 or higher, abbreviated as LCFA); concentration of total cis-fatty acids; concentration of total trans-fatty acids; and average carbon number.

Preferably, the fat fractions are different in two or more, more preferably three or more, four or more, five or more, six or more of said aspects. In an embodiment, the fat fractions are different in twelve or less, in particular ten or less, more in particular eight or less of said aspects.

Surprisingly, it has been found possible to obtain a fat fractionate which is synergistically different from what is expected on the basis of the differences obtained by only dry fractionation or only supercritical fluid fractionation. As a result, a higher than foreseeable recovery of a component of interest or a better than foreseeable removal of an undesired component can be achieved under otherwise the same conditions for the fractionation techniques. Such synergy adds in particular to the efficiency in an unexpected manner. Further, in an embodiment the synergy is found in a difference in the fat composition, e.g. a difference in the solid fat content, affecting a melting property in a different way. Without being bound by theory it is believed that the complex nature of milk fat as (the major part of) the starting material, compared to a e.g. a plant fat like palm oil, may be a cause of a synergy achievable in accordance with the invention. This complex nature is e.g. reflected in the generally bimodal carbon number distribution of milk fat.

The synergistic difference is defined as an enrichment or depletion in one or more of said aspects compared to the starting material, wherein

synergistically enriched is defined as

CDF+SC/ Cstart > Cstart+SC / Cstart ^ 1 and synergistically depleted is defined as

CDF+SC / Cstart < Cstart+SC / Cstart < 1 in which formulas:

CDF+SC is one of said concentrations in or the carbon number of the fat fractionate obtained by dry fractionation plus the supercritical fluid fractionation of the starting material

Cstart is one of said concentrations in or the carbon number of the starting material, such as AMF.

Cstart+sc is one of said concentrations in or the carbon number of a fat fraction obtained by only super critical fluid fractionation of the starting material

In a preferred embodiment , wherein the fat fractionate is

synergistically enriched CDF+SC / Cstart > Cstart+sc / Cstart > 1.24 , more preferably CDF+SC / Cstart > Cstart+sc / Cstart > 1.4. In an embodiment wherein the fat fractionate is enriched in a component or carbon number, usually CDF+SC / Cstart < 10, in particular CDF+SC / Cstart < 5, more in particular CDF+SC / Cstan <3.5, more in particular CDF+SC /Cstart is about 2.5 or less. In a preferred embodiment wherein the fat fractionate is synergistically depleted CDF+SC / Cstart < Cstan+sc / Cstan < 0.9, more preferably CDF+SC / Cstart <

Cstart+sc / Cstart < 0.8, in particular CDF+SC / Cst rt < Cstan+sc /Cstan < 0.65. in an Cstan+sc / Cstan < 0.9. In an embodiment wherein the fat fractionate is depleted in a component or carbon number, usually Cstan+sc / Cstan >0.01, in particular Cstan+sc / Cstan >0.1, more in particular Cstan+sc / Cstan >0.2, more in particular

Cstart+SC /Cstart IS about 0.3 ΟΓ ΠΙΟΓβ.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

The term "or" as used herein means "and/or" unless specified otherwise.

The term "a" or "an" as used herein means "at least one" unless specified otherwise.

The term "substantial(ly)" or "essential(ly)" is generally used herein to indicate that it has the general character or function of that which is specified. When referring to a quantifiable feature, these terms are in particular used to indicate that it is for at least 75 %, more in particular at least 90 %, even more in particular at least 95 % of the maximum that feature.

The term 'essentially free' is generally used herein to indicate that a substance is not present (below the detection limit achievable with analytical technology as available on the effective filing date) or present in such a low amount that it does not significantly affect the property of the product that is essentially free of said substance. In practice, in quantitative terms, a product is usually considered essentially free of a substance, in particular water, if the content of the substance is 0- 0.5 wt.%, in particular 0 - 0.2 wt.%, more in particular 0 - 0.1 wt.%, based on total weight of the product in which it is present. As will be understood by the skilled person, for certain substances, such as certain aromas or

micronutrients, the presence in the starting material may be well below 0.5 wt. %, 0.2 wt.% or 0.1 wt. % and still have a significant effect on a property of the product.

The term "about" in relation to a value generally includes a range around that value as will be understood by the skilled person. In particular, the range is from at least 15 % below to at least 15 % above the value, more in particular from 10 % below to 10 % above the value, more specifically from 5 % below to 5 % above the value. As used herein, percentages are usually weight percentages unless specified otherwise. Percentages are usually based on total weight, unless specified otherwise.

When referring to a "noun" (e.g. a compound, an additive etc.) in singular, the plural is meant to be included, unless specified otherwise.

For the purpose 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.

When referring herein to fatty acids, these in particular include the fatty acid residues (acyl groups) of triglycerides.

The carbon number is determinably by gas chromatography with flame ionization detection (GC-FID), wherein a sample of a substance to be analysed is dissolved in chloroform and injected in the GC. Identification of the carbon numbers and correction factor for the FID response can be done using BCR-632-A sample 160 from Sigma-Aldrich.

The starting material is usually essentially water-free. The starting material is usually milk fat, in particular milk fat that is essentially free of water (anhydrous milk fat, abbreviated as 'AMF'). AMF can be made in a manner generally known in the art, e.g. using phase inversion and drying. AMF is also commercially available, e.g. from Friesland Campina (Amersfoort, the

Netherlands).

Usually, the milk fat is bovine milk fat, preferably cow milk fat. Buffalo milk fat is another particularly useful starting material. Alternatively, the milk fat may in particular be milk fat from milk of another hoofed ungulate, such as sheep milk fat, goat milk fat or camel milk fat. Of these, goat milk fat is preferred. It is also possible to use a mixture of milk fats from milk from different species of mammals.

Good results have been achieved with a starting material that at least substantially consists of milk fat.

However, it is also possible to include a minor amount (less than 50 wt. %) of one or more other fats, in particular one or more fats from a plant or from aquatic organisms (e.g. fish oil, oil from algae). This can be useful, e.g., to provide a starting material with a high mono- or polyunsaturated fatty acid content, e.g. eicosapentaenoic acid (EPA), docosahexanoic acid (DHA) or arachidonic acid (ARA) content . This is for instance interesting for fat fractions to be used in the preparation of an infant formulation. However, it is also possible to add such fat to a fat fractionate obtained in accordance with a process according to the invention.

The total content of fat other than milk fat in the starting material, usually is 0- 20 wt. %,in particular 1-10 wt.%, more in particular 1-5 wt. %, more in particular 1-2 wt. % . Particularly good results have been achieved with a starting material that consists of milk fat, such as AMF.

A desirable fat fractionate for a specific purpose, can be obtained in accordance with the invention by a specific combination of two or more subsequent fractionations, at least one being a dry fractionation and at least one being a supercritical fluid fractionation.

In particular, good results with respect to synergetic enrichment or synergetic depletion have been achieved with a process wherein first the starting material is subjected to one or more dry fractionation steps, and thereafter at least one resultant fraction of the dry fractionation is subjected to supercritical fluid fractionation. Without being bound by theory, the inventors consider that this the enrichment by means of dry fractionation is influenced by the ratio of certain triglyceride classes that are present in milk fat, which contribute to a favourable fractionation.

The dry fractionation conditions and the supercritical fluid fractionation conditions can be based on common general knowledge, the literature cited in the present disclosure, and the contents of the present disclosure, optionally in combination with a limited amount of routine testing. Milk fat fractions obtained by dry fractionation can also be provided by a supplier, from which these are available, e.g. FrieslandCampina (Amersfoort, the Netherlands).

It is an important finding of the inventors that - dependent on the choice of fat fraction obtained in a fractionation step to be used for a subsequent fractionation and the choice for the final fraction to be recovered as the fat fractionate— distinct enrichments or depletions in one or more of said aspects are achieved. Further process parameters can be modified to alter the composition of the prepared fat fractionate.

The dry fractionation is usually operated under batch conditions. In particular in as far as not described in detail in the present disclosure, the dry fractionation conditions can generally be based on known conditions, e.g. on the basis of the references mentioned above or the literature cited therein. E.g. The Lipid Handbook, G.D.Gunstone, CRC Pressm, 3^rd Edition, Chapters 4.4.2.4 and 4.4.3, Figure 4.20 and Table 4.17 are indicative of common general knowledge. Figure 1 of the present disclosure illustrates (using AMF from cow milk as an example) how a multiple fractionation results in different fractions, how these fractions are generally named, and how the melting temperatures of the fractions usually relate to each other. It should be noted that the quantitative values are indicative only and may vary, in particular dependent on the composition of the starting material.

For the supercritical fluid fractionation, the choice of supercritical fluid, feed temperature, ratio supercritical fluid to starting material respectively intermediate fat fraction to be subjected to supercritical fluid fractionation

("solvent/feed ratio"), outlet temperature, pressure, weight to weight ratio distillate to raffinate play a role. Supercritical carbon dioxide is particularly suitable, but other known supercritical fluids can be used as an alternative or mixed with carbon dioxide, e.g. one or more supercritical fluids selected from the group of supercritical dinitrogen oxide, supercritical ammonia, supercritical hydrocarbons, supercritical alcohols, halogenated hydrocarbons. Supercritical points for such fluids are known, e.g. from EP 744922 Bl. In particular in as far as not described in detail in the present disclosure, the supercritical conditions can generally be based on known conditions, e.g. on the basis of the references mentioned above or the literature cited therein.

The supercritical fractionation can be carried out using equipment that is known per se. It can be a continuous fractionation or a batch fractionation.

The temperature of the supercritical medium during fraction may be chosen within a wide range. The temperature is minimally the temperature corresponding to the critical point of the supercritical medium. With a view to an increased drying capacity, the temperature is preferably at least 5°C above the critical point, more preferably at least 10°C above the critical point, most preferably at a temperature of at least 15°C above the critical point.

With a view to the heat load, degradation of a substance of interest and/or the energy consumption, the temperature is preferably maximally 100°C, more preferably maximally 80°C, more in particular maximally 70°C. The temperature is usually chosen such that the fat fraction or starting material subjected to supercritical fractionation is fluid, i.e. above the upper end of the melting range. In particular good results have been achieved with supercritical carbon dioxide at a temperature above the critical point in the range of 45-65 °C.

The pressure of the supercritical medium may be chosen within a wide range. The pressure is minimally the pressure corresponding to the critical point of the supercritical medium. With a view to a favorable extraction capacity, the pressure is preferably at least 5 bar above the critical point, more preferably at least 10 bar above the critical point. The pressure is usually up to 500 bar above the critical point, in particular 200 bar above the critical point, preferably up to 150 bar above the critical point, in particular up to 100 bar above the critical point. For carbon dioxide, the pressure usually is in the range of 100-250 bar, preferably in the range of 105-200 bar. In particular, good results have been achieved with supercritical carbon dioxide at a pressure above the critical point in the range of 110-140 bar.

The solvent/feed ratio can be chosen at a suitable value within a normal operating range for the equipment is used. The ratio is generally chosen high enough to dissolve all of the feed in the supercritical fluid and can be determined empirically. At higher operating pressure, generally a lower solvent/feed ratio is required to dissolve all of the feed.

The inventors further found the ratio distillate to raffinate to be a particularly important parameter, to achieve specific, in particular synergistic effects on enrichment or depletion of one or more components of interest. Usually the weight to weight ratio distillate to raffinate, based on the total weight of the fat fraction(ate) in the distillate and in the raffinate, in the supercritical fluid fractionation is in the range of 5:95 to 90:10 , preferably in the range of 10:90 to 70:30, in particular in the range of 15:85 to 50:50. The following Tables give guidance to possibilities to obtain fat fractions synergistically enriched or depleted in one or more aspects, by choosing a sequence of fractions to proceed with for further processing and/or by altering the ratio raffinate/ distillate. By way of example, two ratios for raffinate to distillate are given. It will be understood by the skilled person that different ratios for raffinate to distillate can be employed and that deviations from the guidance may be achieved by altering the starting material composition and fractionation conditions.

Table 1: Synergy enrichment guidance (using anhydrous milk fat (AMF) as starting material,; '+ 'marks synergy')

Start fraction

Parameter:

C4:0

C6:0

C12:0

C14:0

C16:0

C18:0

C18:1

Cholesterol

Vitamin A

Vitamin Kl Vitamin K2

Table 2: Synergy depletion guidance (using anhydrous milk fat (AMF) as starting material, ; '- 'marks synergy)

Start fraction

Parameter:

C4:0

C6:0

C12:0

C14:0

C16:0

C18:0

C18:1

Cholesterol

Vitamin A

Vitamin Kl Vitamin K2

The skilled person will be able to determine on the basis of common general knowledge, the literature cited herein and the present disclosure, optionally in combination with a limited amount of routine testing, how the differences in aspects may affect the properties of the fat fraction. E.g., a high unsaturated fatty acid content is generally regarded as providing increased nutritional value and tends to have a lowering effect on melting temperature or range. Lactones, ketones and aldehydes generally contribute to a characteristic flavour/aroma.

In a preferred embodiment, a fluid fraction provided by dry fractionation is used as an intermediate fat fraction from the starting material (if dry fractionation precedes supercritical fluid fractionation), or the fat fractionate is obtained as a fluid fraction of the dry fractionation (if dry fractionation follows supercritical fluid fractionation).

In a preferred embodiment, the dry fractionation is a multi-step fractionation comprising two or more fractionation steps, wherein the intermediate fat fraction is a solid or fluid fraction obtained after subjecting a fluid fraction of the starting material obtained in a first dry fractionation step is subjected to at least one further dry fractionation step.

In an alternatively preferred embodiment, the fat fractionate is a solid or fluid fraction obtained after subjecting a fluid fraction of an intermediate fat fraction (obtained by supercritical fluid fractionation) which fluid fraction is obtained in a first dry fractionation step to at least one further dry fractionation step.

Although it is possible to provide a plurality of different useful fat fractions in a single process according to the invention (e.g. both raffinate(s) and distillate (s) of a supercritical fluid fractionation of one or more fractions of a dry fractionation process), the invention has been found particularly advantageous with respect to fat fractions obtained as a distillate or raffinate, more in particular as a raffinate of the supercritical fluid fractionation in a process according to the invention.

A fat fractionate obtained in accordance with the invention may be used as such or be further processed. E.g. it may be subjected to a further fractionation step (dry fractionation, supercritical fractionation or other) or to an

interesterification step. A fraction obtained in a process according to the invention that is not to be used for further application e.g. for used in the making of a food product, may be subjected to a further process to recover useful components from the fraction. E.g. it may be recycled into a process of the invention.

Particularly good results have been achieved with a process, wherein the prepared fat fraction is obtained from the 0 fraction (the fluid fraction of the first dry fractionation step) of the dry fractionation, which 0 fraction has been subjected to supercritical fluid fractionation or may have been subjected to a further dry fractionation step to yield the intermediate fraction (e.g. OS, 00, OSO, OSS, OOO, OSOO, OOOO, OSSO) that has been subjected to supercritical fluid fractionation. However, it is also possible to use the solid fraction of a single dry fractionation (S) or a fraction of the S fraction obtained in a further dry

fractionation (e.g. SO, SS) as the intermediate fraction for supercritical fluid fractionation.

As a guidance, herein below a number of examples are given for applications and/or characteristics of various fractions. Herein, and throughout the present disclosure: the term 'distillate' is used for the distillate of the supercritical fluid fractionation; the term raffinate is used for the raffinate of the supercritical fluid fractionation; lower melting fraction means olein fractions having a lower melting temperature than the starting material, in particular AMF (typically including 0, 00, 000, 0000 etc.); middle melting fraction means stearin fractions having a lower melting temperature than the starting material, in particular AMF (typically including OS, OOS, OOOS high melting fractions means a higher melting temperature than the starting material, in particular AMF

(typically including S, SS, SSS, SSSS ) and the olein fractions obtained from these fractionations SO, SSO, SSSO; soft fraction means the olein fraction of a dry fractionation; hard fraction means the stearin fraction of a dry fractionation.

A distillate of a lower melting fraction is in particular useful as milk fat product with high amounts of naturally occurring bioactive components important for growth and development, such as fat soluble vitamins, vitamin precursors, cholesterol, etc.. A distillate of a lower melting fraction or intermediate melting fraction is in particular useful as fat product containing high concentrations of short chain fatty acids, such as butyric acid, and/or medium chain fatty acids with immunogenic potential.

A fat fractionate with enhanced medium chain fatty acids for energy metabolism can be prepared as a distillate of a hard fraction obtained in the dry fractionation.

High melting fractions are particularly useful for supercritical fluid fractionation to obtain a fat fractionate that is depleted in palmitic acid, without comprising the functionality thereof.

Supercritical fat fractions obtained from hard intermediate fat fractions are particularly useful in the preparation of chocolate or chocolate fantasy products which are more resistant to blooming caused by large temperature fluctuations.

Distillates of soft fractions are for instance useful if starting material contains a relatively high trans-fatty acid and a reduction of trans-fatty acid content is desired.

A distillate obtained by supercritical fluid fractionation of a middle melting fraction, is usually enriched in flavour components, in particular if a dry fractionation fraction is used that is obtained as the liquid fraction in the final dry fractionation step {e.g. O, OO , OOO, or OOOO). A relatively low weight to weight ratio of distillate to raffinate is preferred for preparing a fat fractionate enriched in aroma components, such as a ratio of 30:70 or less, in particular about 15:80 to 20:80. Such fractionate is particularly useful to impart a butter- like or cream like flavour or aroma to a product or for use as a flavour carrier.

A raffinate, in particular a raffinate obtained by supercritical fluid fractionation of an intermediate fat fraction obtained by dry fractionation selected from 0, 00, OOO and OOOO, is suitable to provide a fat fractionate more closely resembling the fatty acid composition of human milk. Accordingly, such fractionate is particularly useful for the preparation of an infant formulation or toddler food.

In case an enrichment of SCFA is desired, a distillate obtained with a process wherein the supercritical fluid fractionation is operated at a relatively low weight to weight ratio distillate to raffinate, such as of about 50:50 or less, is preferred.

For a raffinate enriched in long chain saturated fatty acid, preferably use is made of an intermediate fat fraction obtained by dry fractionation selected from OS and OOO.

For enrichment in cholesterol, vitamin E or vitamin K, a distillate of a solid intermediate fraction obtained by dry fractionation is useful (especially S), in particular if the ratio distillate to raffinate is relatively low, such as about 50:50 or less.

For enrichment in vitamin A use may be made of a supercritical fluid fractionation with a relatively high ratio distillate to raffinate, such as a ratio of about 50:50 or more. For a synergistic enrichment of vitamin A, supercritical fluid fractionation of the OOO fraction of dry fractionation has been found particularly suitable (with the raffinate as the fat fractionate that is

synergistically enriched in vitamin A).

The invention further relates to the preparation of food products using a fat fractionate (obtainable) in accordance with the invention. The food product can generally be prepared in a manner known per se, using known ingredients other than the fat fractionate in known amounts. The fat fractionate will usually replace partly or fully a conventional fat source. E.g. in case chocolate product or chocolate imitation product is prepared, the fat fractionate will usually replace cacao butter or a part thereof.

In a particularly preferred embodiment, the food product is a chocolate product or a chocolate-imitation product.

In a particularly preferred embodiment, the food product is an infant formulation.

In a particularly preferred embodiment, the food product is a medical food product, in particular a clinical nutrition product (i.e. a food product for use in enhancing, maintaining or restoring health and/or prevent a disease, prescribed by a health care professional like a physician, nurse, or dietician, and destined for and supplied to persons in need thereof). The medical food product may be an infant formulation for infants in need of a special nutrition, e.g. for infants suffering from an allergy or metabolic disease. In a particularly preferred embodiment, the obtained product is used to manufacture a flavour product or used directly for inclusion in a flavour product.

The invention will now be illustrated by the following examples. Example 1:

AMF from cow milk was subjected to dry fractionation in a single step fractionation to obtain an 0 and an S fraction, and to multi-step fractionation to obtain various soft and hard fractions, for further fractionation by supercritical fluid fractionation. The dry fractionation process parameters were based on common general knowledge to obtain the fractions.

The supercritical C02 extraction took place on a pilot facility with a 4.5 m high and 10 1 capacity column filled with 2 mm stainless steel Raschig rings. The inner diameter of the column was 54mm. In all tests the raw material was fed from the middle of the column (2.25 m from the bottom). First optimal conditions were determined using AMF and dry fractionation fractions as a feed material using batch extraction experiments. Also conditions were determined to achieve different distillate / raffinate ratios.

These settings were the starting conditions for continuous extraction experiments using different starting milk fat fraction and achieving different distillate / raffinate yields the latter grouped by 15/85 and 50/50.

The settings are compiled in Table 3.

Table 3

All starting materials were heated to 65°C prior to extraction to avoid crystallization in the column. For that reason the column temperature for the S fraction was slightly higher compared to the mid and soft fractions.

Raffinates and distillates were collected in glass jars and stored at refrigerator temperature prior to chemical / sensory analysis.

Example2:

In order to prepare a product with a high amount of butyric acid for use as a base for preparing a milk fat fraction with anti- microbial properties in the GI tract for possible use in medical or child nutrition, the following experiment was carried out: AMF (from cow milk) and an OOOO fraction were prepared as raw materials and analysed on butyric acid by means of fatty acid (FA) analysis by measuring the methyl-esters of the hydrolysed fatty acids using GC equipped with FID detection.

The OOOO fraction and the AMF were subjected to continuous supercritical fractionation; conditions were based on the findings of Example 1. A distillate and a raffinate were obtained under the same conditions. In this case comparable yields of 15% distillate versus 85% of raffinate were obtained for both the AMF and the OOOO fraction. The distillates were analysed by the same FA analysis. In the following table the results are shown.

Table 4

If we consider the synergy equations described above the synergy factor for AMF needs to be >1 and the synergy factor for OOOO needs to be larger than for AMF which is both true. So in this case there is synergistic enrichment of butyric acid in these fractions.

Example 3:

In order to produce a milk fat with substantially lowered amounts of saturated fat (typically below 50%) for use in bakery products, chocolate, butter or other products that are typically considered to contain too high levels of saturated fats, the following experiment was carried out: AMF and an 000 fraction were prepared as raw materials and analysed on saturated fat content by means of fatty acid analysis, as described in Example 2. The 000 fraction and the AMF were subjected to continuous supercritical fractionation; conditions were based on the findings of Example 1. A distillate and a raffinate were obtained under comparable conditions. In this case comparable yields of 50% distillate versus 50% of raffinate were obtained for both the AMF and the 000 fraction. The distillates were analysed by the same FA analysis. In the following table the results are shown: Table 5

If we consider the synergy equations described above the synergy factor for depletion ,AMF needs to be <1 and the synergy factor for OOOO needs to be lower than for AMF which is both true. So in this case there is synergistic depletion of saturated fat in the fraction obtained by a combination of supercritical C02 fractionation and dry fractionation.

Example 4:

In order to produce a milk fat with substantially lowered amount of trans fatty acids for dietary reasons, the following experiment was carried out: AMF and an OOOO fraction were prepared as raw materials and analysed on trans fatty acid content by means of fatty acid analysis, as described in Example 2. The OOOO fraction and the AMF were subjected to continuous supercritical fractionation; conditions were based on the findings of Example 1. A distillate and a raffinate were obtained under comparable conditions. In this case comparable yields of 15% distillate versus 85% of raffinate were obtained for both the AMF and the OOOO fraction. The distillates were analysed by the same FA analysis. In the following table the results are shown:

Table 6

If we consider the synergy equations described above the synergy factor for depletion ,AMF needs to be <1 and the synergy factor for OOOO needs to be lower than for AMF which are both true. So in this case there is synergistic depletion of trans fatty acids in the fraction obtained by a combination of supercritical C02 fractionation and dry fractionation.

Example5:

In order to prepare a product with a high amount of medium chain fatty acids (C6:0-C12:0) for use as a base for preparing a milk fat fraction with immunogenic properties in the GI tract, e.g. for use in medical nutrition or child nutrition, the following experiment was carried out: AMF (from cow milk) and an OOO fraction were prepared as raw materials and analysed on these medium chain fatty acids by means of fatty acid (FA) analysis. The OOO fraction and the AMF were subjected to continuous supercritical fractionation; conditions were based on the findings of Example 1. A distillate and a raffinate were obtained under comparable conditions.

In this case comparable yields of 50% distillate versus 50% of raffinate were obtained for both the AMF and the OOO fraction. The distillates were analysed by the same FA analysis as in Example 2. In the following table, the results are shown: Table 7

If we consider the synergy equations described above the synergy factor for AMF needs to be >1 and the synergy factor for OOO needs to be larger than for AMF which is both true. So in this case there is synergistic enrichment of medium chain fatty acids in these fractions.

Example6:

In order to prepare a product with a higher amount of omega-3 fatty acids for nutritional reasons, the following experiment was carried out: AMF (from cow milk) S, OS and an OOO fraction were prepared as raw materials and analysed on these omega-3 fatty acids by means of fatty acid (FA) analysis. The fractions were subjected to continuous supercritical fractionation; conditions were based on the findings of Example 1. A distillate and a raffinate were obtained under comparable conditions. In this case comparable yields of 50% distillate versus 50% of raffinate were obtained for both the AMF and the OOO fraction. The raffinates were analysed by the same FA analysis as in Example 2. In the following table the results are shown:

Table 8

Example 7:

In order to demonstrate that flavour molecules can be concentrated synergistically by means of supercritical C02 fractionation, the following tests was performed. AMF (from cow milk) and an OOOO fraction were prepared as raw materials. Equal amounts of these products were put in aluminium coated glass jars at room temperature. These samples were tested blindly by an experienced group of testers familiar with butter and butter products against a standard which was AMF and asked to grade the product on a 5 point scale, 1 clearly less intense, 2: slightly less intense, 3 equally intense, 4: slightly more intense and 5: clearly more intense. The ranking points were collected per person added per sample and summarised in the following table. In this table it can be seen that also in the flavour intensity, there is a clear benefit of combining supercritical and dry fractionation, since the panel is almost unanimous in scoring the flavour of the distillate of the OOOO fraction as clearly more intense in comparison to the AMF fraction or the OOOO dry fraction as is. Table 9

Flavor Flavor Flavor

Intensity Intensity Intensity

(product as (product (product is) raffinate) distillate)

AMF 15 7 22

0000 18 6 24 fraction

Claims

1. A process for preparing a fat fractionate, comprising

providing an intermediate fat fraction of a starting material selected from the group consisting of milk fats and fat mixtures of milk fat and at least one other fat, which fat mixtures are composed of more than 50 wt. % milk fat, preferably at least 90 wt. % milk fat - said starting material preferably being anhydrous - by a dry fractionation; and

subjecting said intermediate fat fraction to a supercritical fluid fractionation, wherein the fat fractionate is obtained as a raffinate of the supercritical fluid fractionation or as a distillate of the supercritical fluid fractionation, optionally after removing the supercritical fluid.

2. A process for preparing a fat fractionate, comprising

subjecting said intermediate fat fraction to a single- step or multi-step dry fractionation, wherein the fat fractionate is obtained as a fluid fraction or as a solid fraction of the dry fractionation.

3. Process according to claim 1, wherein the intermediate fat fraction of the starting material is a fluid fraction provided by dry fractionation or process according to claim 2, wherein the fat fractionate is obtained as a fluid fraction of the dry fractionation.

4. Process according to any of the preceding claims, wherein the dry fractionation is a multi-step fractionation comprising two or more fractionation steps, wherein the intermediate fat fraction of claim 1 or claim 3 dependent on claim 1 respectively the fat fractionate of claim 2 or claim 3 dependent on claim 1 is a solid or fluid fraction obtained after subjecting a fluid fraction of a first dry fractionation step to a second dry fractionation step.

5. Process according to claim 1 or any of the claims 3-4 dependent on claim 1, wherein the fat fractionate is the raffinate of the supercritical fluid fractionation or process according to claim 2 or any of the claims 3-4 dependent on claim 2, wherein the intermediate fat fraction is a raffinate of the supercritical fluid fractionation.

6. Process according to any of the preceding claims, wherein the prepared fat fractionate is different from the starting material and from the intermediate fat fraction in one or more of the following aspects, preferably at least two of the following aspects, more preferably at least three of the following aspects:

concentration of saturated fatty acids;

concentration of monounsaturated fatty acids;

- concentration of polyunsaturated fatty acids;

concentration of n3-polyunsaturated fatty acids;

concentration of one or more vitamins;

concentration of cholesterol

concentration of lactones

- concentration of ketones

concentration of aldehydes

concentration of short-chain fatty acids (C4-C6)

concentration of medium-chain fatty acids (C8-C12)

concentration of long-chain fatty acids (C14-C20)

- concentration of cis-fatty acids

concentration of trans -fatty acids

average carbon number

7. Process according to claim 6, wherein the prepared fat fractionate is synergistically enriched or depleted compared to the starting material, wherein synergistically enriched is defined as

CDF+SC/ Cstart > Cstart+SC / Cstart ^ 1 and

synergistically depleted is defined

CDF+SC / Cstart < Cstart+SC / Cstart < 1 in which formulas: CDF+SC is one of said concentrations in or the carbon number of the fat fractionate obtained by dry fractionation plus the supercritical fluid fractionation of the starting material

Cstart is one of said concentrations in or the carbon number of the starting material, such as AMF

8. Process according to any of the preceding claims, wherein the starting material comprises 95- 100 wt. % milk fat and 0-5 wt. % vegetable fat, preferably 98- 100 wt. % milk fat and 0-2 wt. % vegetable fat.

9. Process according to any of the preceding claims, wherein the supercritical fluid is CO2.

10. Process according to any of the preceding claims, wherein the milk fat is cow milk fat.

11. Process according to claim 10, wherein the milk fat is anhydrous cow milk fat.

12. Fat fraction, obtainable as a fat fractionate by a process according to any of the claims 1-11,

13. Method for making a food product, comprising combining a fat fractionate prepared by a process according to any of the claims 1-11 or a fat fraction according to claim 12, with one or more further (usual) food ingredients for making said food product

14. Method according claim 13 wherein the food product is an infant food formulation.

15. Method according claim 13, wherein the food product is a chocolate product or a chocolate-imitation product.

16. Method according to claim 14 or 15, wherein the food product is a medical food product, in particular a clinical nutrition product (i.e. a food product for use in enhancing, maintaining or restoring health and/or prevent a disease, prescribed by a health care professional like a physician, nurse, or dietician, and destined for and supplied to persons in need thereof).