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Title:
BUTTER SUBSTITUTE
Document Type and Number:
WIPO Patent Application WO/2019/048620
Kind Code:
A1
Abstract:
The invention relates to a method for preparing a food composition comprising dairy fat and casein, comprising subjecting a suspension of the oil-in-water type comprising dairy fat and micellar casein to a treatment wherein casein is coagulated and fat is rebodied. The obtained food composition is (at 20 °C) a solid suspension of the oil-in-water type. The invention further relates to a dairy food composition, which composition is a suspension of the oil-in-water type, comprising 1-6 wt. % dairy protein, said dairy protein comprising coagulated casein; 20-55 wt. % fat, of which at 50-100 wt. % is dairy fat; 40-79 wt.% water; and 0-10 wt.% other ingredients.

Inventors:
PENDERS, Johannes Antonius (6700 AE Wageningen, 6700 AE, NL)
TAP, Wilhelmus Hendricus Johannes (6700 AE Wageningen, 6700 AE, NL)
GIELENS, Fransiscus Christophorus (6700 AE Wageningen, 6700 AE, NL)
KORNET, Cornelis (6700 AE Wageningen, 6700 AE, NL)
Application Number:
EP2018/074159
Publication Date:
March 14, 2019
Filing Date:
September 07, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
FRIESLANDCAMPINA NEDERLAND B.V. (Stationsplein 4, 3818 LE Amersfoort, 3818 LE, NL)
International Classes:
A23C9/15; A23C19/02; A23D7/005
Domestic Patent References:
WO2013151423A12013-10-10
Foreign References:
US3749583A1973-07-31
CA2212701A11999-02-08
US5916608A1999-06-29
DE10104945A12001-08-23
Other References:
ANONYMOUS: "Dickete - Wikipedia", 12 May 2015 (2015-05-12), pages 1 - 2, XP055423945, Retrieved from the Internet [retrieved on 20171110]
ANONYMOUS: "GNPD - Doppelrahm Crème Double", July 2014 (2014-07-01), pages 1 - 2, XP055423430, Retrieved from the Internet [retrieved on 20171109]
P. WALSTRA; J. T. M. WOUTERS; T. J. GEURTS, DAIRY SCIENCE AND TECHNOLOGY, vol. 4, 2006
D. S. HOME; J. M. BANKS: "Rennet-induced Coagulation of Milk", vol. 1, 2004, ELSEVIER LTD
C. PHADUNGATH: "Casein micelle structure : a concise review", J. SCI. TECHNOL., vol. 27, May 2004 (2004-05-01), pages 201 - 212
K. BOODE; C. BISPERINK; P. WALSTRA: "Colloids and Surfaces", vol. 61, 1991, article "Destabilization of O/W emulsions containing fat crystals by temperature cycling", pages: 55 - 74
P. WALSTRA; J.T.M. WOUTERS; T.J. GEURTS: "Dairy Science and Technology", 2006, CRC PRESS, pages: 132 - 134
Attorney, Agent or Firm:
FRIESLANDCAMPINA NEDERLAND B.V. (Bronland 20 P.O. Box 238, 6700 AE Wageningen, 6700 AE, NL)
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Claims:
Claims

1. Method for preparing a solid dairy food composition comprising dairy fat and casein, which food composition is (at 20 °C ) a solid suspension of the oil-in-water type, said method comprising the steps of:

a) providing a fluid suspension of the oil-in-water type comprising solid dairy fat and micellar casein; thereafter

b) providing a fluid mixture comprising solid fat, liquid fat and coagulated casein by

(i) increasing the temperature of the fluid suspension, allowing melting of part of the solid dairy fat into liquid fat; and

(ii) coagulating the micellar casein before, during or after increasing the temperature; and

c) subjecting the fluid mixture to a fat solidification step wherein at least part of the liquid fat solidifies, thereby obtaining the solid dairy food composition.

2. Method according to claim 1, wherein

step a) comprises subjecting a fluid starting suspension of the oil-in-water type comprising dairy fat and micellar casein, which starting suspension comprises dairy cream, to a fat solidification step at a temperature in the range of 0-20 °C until at least 80 wt. % of the fat is solid, thereby providing the fluid suspension of the oil-in-water type comprising solid dairy fat and micellar casein; and/or

step b)(i) comprises increasing the temperature of said fluid suspension of the oil-in- water type comprising solid dairy fat and micellar casein to more than 20 °C and step b) (ii) comprises chemically and/or enzymatically coagulating the micellar casein, thereby obtaining the fluid mixture comprising 1.5 to 10 wt.% solid fat, based on total fat, liquid fat and coagulated casein; and/or

step c) comprises reducing the temperature of the fluid mixture to a value in the range of 0-10 °C, thereby obtaining the solid dairy food composition. 3. Method according to claim 1 or 2, wherein fat solidification in step (a) takes place at a temperature in the range of 0-10 °C.

4. Method according to any of the preceding claims, wherein the coagulation comprises enzymatic coagulation of casein using a protease.

5. Method according to claim 4, wherein the protease is rennet.

6. Method according to any of the preceding claims, wherein the coagulation comprises acid coagulation of casein.

7. Method according to any of the preceding claims, wherein in step (b) the temperature is increased for about 0.5 to about 2.5 hours to a temperature in the range of 30 °C to 40 °C. 8. Method according to any of the preceding claims, wherein in step (c) the temperature is reduced at an average cooling rate of 3.0 °C /min or less.

9. Method according to any of the preceding claims, wherein a salt of a divalent cation is added to the fluid suspension of step (a) prior to or during step (b) or to the fluid mixture obtained in step b).

10. Method according to any of the preceding claims, wherein the fluid suspension provided in step (a) comprises a cream selected from cow

milk cream, caprine milk cream and sheep milk cream.

11. Dairy food composition, which composition is (at 20 °C ) a solid suspension of the oil-in-water type, is spreadable at 15 °C and comprises

1-6 wt. % dairy protein, said dairy protein comprising coagulated casein;

20-70 wt. % fat, of which at 50-100 wt. % is dairy fat;

40-79 wt.% water; and

0-10 wt.% other ingredients.

12. Dairy food composition according to claim 11, comprising

1.5-3.0 wt.% casein;

35-50 wt. % milk fat, preferably 38-45 wt.% milk fat;

45-55 wt. % water; and

0-10 wt.% other ingredients.

13. Dairy food composition according to claim 11 or 12, having a firmness at 15 °C, in the range of 0.05-0.4 N.

14. Dairy food composition according to any of the claims 11-13 having a pH in the range of 4.5-6.8.

15. Use of a dairy food composition according to any of the claims 11-14 as a spread for bread or another baked cereal product, as a baking fat, as a cooking fat, in a bakery cream application, e.g. as a topping or filling for a cake, cookie or in a confectionary application.

Description:
Title: Butter substitute

The invention relates to a fat-containing dairy food composition, which composition is solid at 20°C, and in particular to a fat-containing dairy food composition that is spreadable below room temperature. The invention also relates to a method to prepare this composition and to compositions obtainable by this method. Finally, the invention relates to the use of these compositions as a spread for bread or as baking fat instead of butter.

Butter is a dairy product with many uses in the preparation of food products.

Besides its popular use as a spread on bread or as baking or cooking fat, it can e.g. be used in various bakery applications. Butter is a suspension of the water in oil type. Water droplets are dispersed in the butterfat phase, which makes up about 80 % of the product. The butterfat gives the product a distinct taste, but the high saturated fat content and the high calorific value of butter are also considered a health concern.

Further, although the high content of butter fat provides butter with good spreading properties at room temperature, e.g. on bread, it makes butter rather hard and difficult to spread at lower temperature, in particular at typical refrigerator temperature (about 4 °C).

Various alternatives for butter have been developed, including alternatives based on vegetable fats and alternatives based on milk fat or fractions thereof with an increased water content and a reduced fat content. However, the change in fat composition (quantitatively and/or qualitatively) generally has an effect on its properties, notably olfactory properties, textural properties, product consistency at ambient or refrigerated temperature, product spreadability at ambient or refrigerated temperature etc. One may try to adjust one or more of these properties by addition of additives to a fat composition used as a basis to make a spreadable fat product.

In DE 101 04 945 Al it is proposed to make a spreadable fat product with a butter-like consistency by adding phospholipids, dietary fibre and enzymes

(transglutaminases) to a phase containing 20-70 % fat and prepare an emulsion with a satisfactory consistency to make it spreadable. To accomplish this a homogenization treatment is carried out, typically at an elevated temperature after adding the further ingredients at an elevated temperature to the fat- containing phase. A heat treatment of the total mixture to improve shelf life and consistency at pasteurization temperature or higher is typically carried out before homogenization. There is a general need for further alternatives for traditional butter, in particular an alternative that contains less fat than butter yet has a butter-like taste and/or mouthfeel and/or that has better spreading properties at ambient and/or refrigerated temperature and/or that has a reduced tendency to splashing of water when heated above 100 °C, e.g., in a frying pan.

Further, there is a need for alternative methodology to prepare an alternative for traditional butter, especially a method that is more simple than the methods described in detail in DE 101 04 945 Al, in particular a method that can be carried out a relatively mild temperature (such as below a temperatures required for pasteurisation) and/or that does not require a homogenization treatment of the mixture from which the alternative for butter is made.

It is an object of the invention to address a need as described above. One or more further objects which may be addressed in at least specific embodiments follow from the description below.

It has now been found possible to provide a food composition that is solid at

20 °C substantially based or fully based on dairy food ingredients that can be used as an alternative for butter, which product generally has a lower fat content than butter, and that can be prepared following a relatively simple process comprising rebodying of fat and coagulation of dairy protein.

Accordingly, the present invention relates to a method for preparing a food composition comprising dairy fat and casein which food composition is solid at 20°C, the method in essence comprising subjecting a suspension of the oil-in-water type comprising dairy fat and micellar casein to a treatment wherein casein is coagulated and fat is rebodied.

The present invention thus relates to a method for preparing a solid dairy food composition comprising dairy fat and casein, which food composition is (at 20 °C ) a solid suspension of the oil-in-water type, said method comprising the steps of:

a) providing a fluid suspension of the oil-in-water type comprising solid dairy fat and micellar casein; thereafter

b) providing a fluid mixture comprising solid fat, liquid fat and coagulated casein by

(i) increasing the temperature of the fluid suspension, allowing melting of part of the solid dairy fat into liquid fat; and

(ii) coagulating the micellar casein before, during or after increasing the temperature; and c) subjecting the fluid mixture to a fat solidification step wherein at least part of the liquid fat solidifies, thereby obtaining the solid dairy food composition.

In a particularly preferred method according to the present invention step a) comprises subjecting a fluid starting suspension of the oil-in-water type comprising dairy fat and micellar casein, which starting suspension comprises dairy cream, to a fat solidification step at a temperature in the range of 0-20 °C until at least 80 wt. % of the fat is solid, thereby providing the fluid suspension of the oil-in-water type comprising solid dairy fat and micellar casein; and/or

step b)(i) comprises increasing the temperature of said fluid suspension of the oil-in- water type comprising solid dairy fat and micellar casein to more than 20 °C and step b)(ii) comprises chemically and/or enzymatically coagulating the micellar casein, thereby obtaining the fluid mixture comprising 1.5 to 10 wt.% solid fat based on total fat (preferably 2.5 to about 8 wt.% solid fat based on total fat), liquid fat and coagulated casein; and/or

step c) comprises reducing the temperature of the fluid mixture to a value in the range of 0-10 °C, preferably 1-5 °C, thereby obtaining the solid dairy food composition

Each of the preferred embodiments for steps a), b) and c) indicated above can be applied individually or in combination.

Further, the invention relates to a food composition, which composition is a suspension of the oil-in-water type, which composition is solid at 20°C and spreadable at 15 °C, preferably spreadable at 4 °C, which composition comprises

1-6 wt. %, preferably 1-4 wt. %, dairy protein, said dairy protein comprising coagulated casein;

20-70 wt. %, preferably 30-55 wt.%, more preferably 38-45 wt.% fat, of which at 50-100 wt. % is dairy fat;

40-79 wt.%, preferably 40-60 wt. % water, more preferably 45-55 wt.% water.

The dairy protein, fat and water generally form 80-100 wt.% of the food composition (obtainable) according to the invention. The total content of other ingredients is preferably 0- 10 wt.%.

Furthermore, the invention relates to use of a dairy food composition according to the invention or obtainable by a method according the invention as a spread for bread or another baked cereal product, as a baking fat, as a cooking fat, in a bakery cream application, e.g. as a topping or filling for a cake, cookie or in a confectionary application.

Thus, the invention further relates to a composite food product comprising a solid food composition according the invention and a further food component, such as a baked cereal product, chocolate etc.

Being able to prepare the composition at moderate temperature (after an optional antimicrobial heat treatment prior to (the end of ) step a) ) throughout the method or at least starting from step b) is advantageous not only from the view of method simplicity and energy consumption. A method according to the invention is inter alia advantageous it that it is generally carried out whilst maintaining the temperature below a temperature at which undesirable detrimental effects, such as substantial thermal protein denaturation, loss of aroma or other undesired olfactory changes due to thermal effects occur. After an optional thermal sanitizing heat treatment (e.g.

pasteurisation or UHT treatment) of a starting material (e.g. cream) prior to the provision of the fluid suspension comprising solid fat in step (a), the temperature in a method of the invention typically remains at a temperature at which at least part of the fat remains solid. As will be understood by the skilled person in particular in view of the description below, a suitable maximum temperature can vary dependent on the fat composition. In general, particular good results have been achieved with a method wherein the temperature at least starting from the temperature increase of the fluid suspension comprising solid fat at the beginning of step b) or the end of step a) is maintained below about 45 °C, in particular at a temperature in the range of 0-40 °C.

It is further an advantage of the invention that temperature changes in the various steps can be carried out without special equipment to ensure a strict

temperature ramping (e.g. a linear temperature increase/decrease rate). Good results have been achieved with a method wherein temperature decrease respectively temperature increase are accomplished by placing a container (e.g. a sealed package suitable for selling the composition in)) in an environment (e.g. a storage room, such as a fridge or heating chamber or a liquid bath) having an essentially constant low temperature respectively having an essentially constant high temperature, and letting the container stand therein for a time sufficient to reach the effects of the invention.

A homogenization treatment is not required either. Although in principle a homogenization treatment may be applied to e.g. the suspension provided in step (a), to a starting material used to provide said suspension, usually at least after step b), and preferably after step a), preparation of the food composition is done without substantial homogenization treatment. At least once the suspension comprising solid fat is provided, the suspension is usually treated without applying substantial shearing. Thus, advantageously, step (c), steps (b) and (c), or each of steps (a) to (c) are carried out in a packaging which packaging is sealed. Preferred Examples of such packaging are typical cups or other containers wherein butter and other fat-based spreads are sold. The volume of such containers is not critical, but in practice usually in the range of 1-5000 ml, in particular 5- 1000 ml, more in particular 10-500 ml. Treatment in the packaging (in which the product is intended to be sold or otherwise marketed) allows simplification over a conventional method requiring homogenization and/or stirring, but carrying out the method in a sealed package is also advantageous from a hygiene perspective.

The invention has in particular been found suitable to provide a food composition with both satisfactory firmness and spreadability (by hand using a knife), below or at room temperature, at a relatively low fat content (compared to butter).

Spreadability below room temperature (e.g. about 15 °C) is generally found to be better than for butter. A food composition according to the invention further has been found to have a taste component reminding of the taste of butter. Thus, the present invention provides an excellent alternative for butter in several aspects.

It was further found that the present invention was suitable to provide a solid food composition that did not show unacceptable syneresis, also after more than a week, in particular after two weeks or more of storage.

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 %, even more in particular at least 99 % 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, 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.

The term 'fatty acid' is generally used herein as a genus for free fatty acids and fatty acid residues bound to another organic moiety, in particular as part of an acylglyceride.

The term 'fat' is used herein for the lipid phase (fat phase) of a suspension or other composition (used) in accordance with the invention, as is common in the art. The fat generally at least substantially consists of tiglycerides, typically for more than 90 wt.%, in particular for 95- 100 wt.%. Other components that may be present include other lipid components that can be naturally found in natural fat phases, e.g. vegetable oils or milk fat, like fat-soluble vitamins (e.g. vitamin A, D or E). Milk fat is the fat phase of milk. Milk fat is a 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. Milk fat (isolated from milk) is commercially available, e.g. in essentially water-free from, which product is generally known as anhydrous milk fat (AMF).

The term 'dairy fat' is used as a genus for milk fat and parts of milk fat. Such parts can be any milk fat fraction, combination of milk fat fractions or combination of a milk fat fraction and milk fat. Parts of milk fat in particular include milk fat fractions that can be obtained by a milk fat fraction process. Such processes are generally known in the art and include milk fat crystallisation (also known as dry fractionation) and supercritical fluid extraction, e.g. using supercritical CO2.

Milk proteins can be divided into three main groups: caseins, serum proteins

(such as B-lactoglobilin, alpha-lactalbumin, serum albumin, protease peptone and immunoglobulins) and miscellaneous proteins (such as lactoferrin, transferrin and membrane enzymes). Further, the term whey proteins is used in the art for proteins that remain in the liquid phase after coagulation of casein from milk, e.g. in the preparation of cheese. Whey proteins comprise serum proteins.

The term 'solid' is used herein for matter, in particular a food composition, which essentially remains its shape when a unit of the matter, such as a cube with a size of 1 x 1 x 1 cm, put on a horizontal surface without further support from the sides or top of the matter, at least in air, at a pressure of 1 bar, at a temperature of 20 °. I.e. with the naked eye solid matter is not visibly fluid. Such matter may also be referred to as self- sustaining matter or dimension-stable matter.

A solid fat content at a specific temperature can be determined by subjecting the fat fraction of the composition to a solid fat content measurement using pulse NMR or DSC. To this purpose standardized methodology is available, see WO2013/151423A1. In particular AOCS Cd 16b-93 revised in 2000 can be used.

Firmness can be determined penetrometrically, using a texture analyser. In particular, the values for firmness as mentioned herein are as determined with a TA- XT2i (Stable Micro Systems, Godalming, England) texture analyser to which a wire cutter probe is attached with a load cell of 50 kg, setting the trigger force to 0.04 N and the test speed to 0.20 mm/s, setting the total penetration distance of the probe through the sample (a cube, having a thickness of 21 mm) at 18.0 mm, determining the force (N) required to press through the sample between 7 and 14 mm penetration; averaging the force required to press through the sample between 7 and 14 mm penetration is the firmness of the composition

In the art spreadability is usually assessed qualitatively. A composition is considered spreadable if a skilled person can manually, using a knife, take a portion of a composition from the bulk of the composition and distribute the portion on the surface of a food product on which the product needs to be spread, typically bread, toast or another baked cereal product, without substantially disrupting the food product. A skilled person will also be able to grade spreadability (e.g. on a 1-10 scale) taking into account how easy it is to spread a composition essentially evenly and the tendency for the composition to curl up from the surface on which it is applied.

For an indication of spreadability one may also make use of rheology measurements. By determining viscosity as a function of shear stress, as described in detail in the Examples, resistance against spreading can be determined.

The pH is defined as the apparent pH as measurable by placing a standard pH electrode in the substance (e.g. suspension or solid food composition) of which the pH is measured, at 20 °C, unless specified otherwise.

As is generally known in the art, casein, as naturally present in milk, is a supramolecular association of individual casein subunits: alpha-sl-, alpha-s2-, beta-, and kappa-casein. These fractions are organized within, a micellar structure according to a balance of interactions involving their hydrophobic and hydrophilic groups. Micellar casein is colloidal, typically essentially spherical, typically having an average diameter of about 200 nm and an average molecular weight of about 108 Da (for casein in cow milk), see e.g. P. Walstra, J. T. M. Wouters, and T. J. Geurts, Dairy Science and Technology, vol. 4. 2006; D. S. Home and J. M. Banks, Rennet-induced Coagulation of Milk, vol. 1, no. C. Elsevier Ltd, 2004. The casein micelles are stabilized by hydrophobic interaction and calcium casemate bridges (C. Phadungath, "Casein micelle structure : a concise review," J. Set TechnoL, vol. 27, no. May 2004, pp. 201-212, 2005)].

'Casemate' is a non-micellar protein derived from casein, obtainable by acid precipitation (coagulation) from a fluid containing solubilised casein (casein micelles) e.g. milk, and subsequent neutralization with a base. Coagulation of casein is a treatment that is generally known in the art per se. It is e.g. part of the production of cheese. The inventors found it can also be carried out in a suspension having a relatively high fat content, such as dairy cream. In a method of the invention, coagulation is usually done by enzymatic coagulation or by addition of a chemical coagulating agent, such as an acid.

Enzymatic coagulation is generally done using a protease, in particular an aspartic endopeptidase (EC 3.4.23.4), more in particular a chymosin, preferably bovine chymosin. For enzymatic coagulation of casein, rennet is preferably used. Particularly good results have been achieved with a bovine rennet. The skilled person will be able to apply a suitable pH, based on the enzyme used. Generally, the pH is in the range of about 4.0 to about 7.0. For enzymatic coagulation the amount of protease, the amount of rennet is usually at least 1 IMCU/1 fluid suspension (e.g. cream). The amount is usually less than 1000 IMCU/1 suspension, preferably about 500 IMCU/1 fluid suspension or less, more preferably about 100 IMCU/1 or less. The lower the amount used, the longer it takes to achieve a certain coagulation. Since enzymatic coagulation in step b) is generally performed in combination with the rebodying of fat at a relatively high temperature, too low an enzymatic activity may result in unsatisfactory coagulation at a point in time in step b), where an intended solid fat content is reached. In such case, one may e.g. proceed with allowing further coagulation at a temperature where no further melting of fat occurs, or one may decide to make use of a combination of acid and enzymatic coagulation.

An amount of protease, in particular rennet, in the range of about 7.5 to about 75 IMCU/1 fluid suspension has been found particularly suitable to provide a solid food composition with a satisfactory firmness and spreadability, at about 15 °C or lower, that is particularly suitable as a substitute for butter, e.g. as a spread on bread or another baked cereal product, e.g. toast or cake. Particularly good results have been achieved within a method wherein the protease (such as rennet) is added in an amount of about 30 to about 60 IMCU/1 fluid suspension.

Alternatively or additionally acid coagulation of casein can be carried out. Acid coagulation comprises adjusting the pH of the fluid wherein the micellar casein is present to a point at which it precipitates (i.e. around the isoelectric point), typically a pH in the range of 4.0-5.5, preferably of about 4.6. Apart from a coagulating effect, an acid can also be used to adjust a flavour property. An acidic food composition according to the invention, in particular a composition having a pH of 4.0-6.0, preferably of about 4.6 has an increased firmness at 15 °C, compared to a comparable food composition having an about neutral pH. On the other hand if an acidic composition is found to be unsatisfactory with respect to spreadability for a specific application, spreadability can be improved by increasing the pH up to about neutral pH, e.g. a pH of about 6.8. If desired, the pH can be reduced after coagulation by adding an acid. However, it has also been found that a salt of a divalent cation, such as Mg or Ca cations, for instance calcium chloride or magnesium chloride is suitable to decrease the pH of a fluid suspension or mixture employed in a method according to the invention. If desired, the pH can be increased after (acid) coagulation by adding a base.

Coagulation is generally carried out during said step b), i.e. at a relatively high temperature within the temperatures generally employed in a method according to the invention. In particular for enzymatic coagulation, enzyme activity of (conventionally used) enzymes is higher at relatively high temperature. Thus, the chemical coagulating agent or enzyme is usually added to the starting suspension prior to step b) or during step b), preferably at the beginning of step b), i.e. whilst the temperature is still increasing (thereby reducing the time needed to accomplish a desired coagulation degree). This is in particular preferred for enzymatic coagulation. Chemical coagulation, such as acid coagulation, may also be carried out at a relatively low temperature. Thus it may be carried out before or after step b), yet before formation of the solid composition in step c). However, for practical reasons adding a coagulation agent (such as an agent reducing the pH) before step b) or during step b) is also preferred for chemical coagulation.

Rebodying (also known as tempering of fat) is a treatment that is generally known in the art, per se. Rebodying comprises subjecting a fluid suspension comprising fat to temperature fluctuations, such that the viscosity increases. This is generally caused by a partial coalescence of fat globules in the fluid. Rebodying can occur with or without stirring. No stirring is needed, if the fat content is so high that the fat globules are sufficiently close together to coalesce, (see e.g. K. Boode, C. Bisperink, and P.

Walstra, "Destabilization of O/W emulsions containing fat crystals by temperature cycling," Colloids and Surfaces, vol. 61, no. C, pp. 55-74, 1991; P. Walstra, J.T.M.

Wouters, T.J. Geurts, "Dairy Science and Technology", Second Edition, CRC Press, 2006, paragraph 3.2.2.2, pp. 132-134).

Thus, as can be understood from the above, rebodying of fat is a treatment for which each of the steps a) - c) are relevant; for coagulation of casein, in general at least step b) is used. Based on the present disclosure and common general knowledge the skilled person will understand that optimal conditions depend to some extent on desired properties of the solid food composition (such as desired olfactory properties,

spreadability, firmness, fat content etc) and the used starting materials(s). Based on the present disclosure and common general knowledge the skilled person will also be able to determine suitable conditions to obtain a food composition according to the invention within the full ambit of the claims.

In step (a) a fluid suspension of the oil-in-water type comprising solid dairy fat and micellar casein is provided. This suspension generally comprises 1-6 wt. % protein, of which generally 80-100 wt.% preferably essentially all protein is dairy protein. Preferably 70-100 wt.% of the protein is casein more preferably at least 80 wt.%. Above a concentration of 4 wt.% case should be taken to avoid lump formation of the coagulating proteins, notably casein. Accordingly the concentration of protein is preferably 1-4 wt.%, more preferably 1-3.0 wt.%, based on total weight. In particular, good results have been achieved with a fluid suspension comprising casein and whey protein in a weight to weight ratio of casein to whey protein in the range of 70:30 to 90:10, in particular in the range of 78:22 to 88:12.

The fat content of the suspension that is provided in step a) is generally 20 wt.% or more, based on total weight of the suspension. For advantageous rebodying, the fat content of the fluid suspension is usually 25 wt.% or more, preferably at least 30 wt.%, more preferably at least 35 wt.% , in particular at least 38 wt.%. based on the weight of the suspension. A relatively high fat content generally results in a relatively high firmness of the obtained solid food composition. The suspension provided in step a) usually has a fat of 70 wt.% or less, in particular of 60 wt.% or less, to avoid a

substantial risk of phase separation (in the absence of non-dairy emulsifiers), preferably of about 55 wt.% or less thus providing a composition with reduced fat content compared to butter. At a higher fat content, an insufficient stability of the oil-in-water suspension can be a problem, at least without addition of (non-dairy) emulsifiers. In a particularly preferred embodiment, the fat content of the suspension is 50 wt. % or less Particularly good results have been achieved with a suspension comprising 38-45 wt. % fat.

Generally more than 50 wt. % of the fat in the provided suspension is dairy fat, preferably 80-100 wt.%, more preferably 90-100 wt.%. Particularly good results have been achieved with a suspension wherein the fat phase essentially consists of milk fat. In a specific embodiment the fat is a blend of milk fat and another fat. E.g, one or more triglycerides comprising an n3-polyunsatured fatty acid (e.g. alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)) and/or an n6- polyunsatured fatty acid may be included (e.g. linoleic acid (LA)) These fatty acids are known to be beneficial from a health perspective. In addition, or alternatively, a specific milk fat fraction can be present, e.g. a stearin fraction of milk fat. Such fraction can advantageously be used to increase the solid fat content at relatively high temperature. This can e.g. be used to allow a relatively high temperature (such as of up to about 45 °C) for step b). A potential reason for that is to allow enzymatic coagulation at or close to the temperature optimum of the used enzyme. Also inclusion of a stearin fraction of milk fat can be done to compensate for a reduction in solid fat content at a relatively high temperature, due to the addition of a fat with a low melting point or range, such as a triglyceride providing a polyunsaturated fatty acid.

Dairy cream or a fluid suspension at least substantially consisting of dairy cream is a particularly suitable fluid suspension to provide this fluid suspension. Cream used in a method according to the invention is usually selected from the group of cow milk cream, caprine milk cream and sheep milk cream. One may also make use of milk fat, e.g. amorphous milk fat obtained from bovine, caprine or sheep milk, which can be suspended together with dairy protein, e.g. at least partially provide in the form of milk protein isolate. Micellar Casein Isolate (MCI) can also provide all or part of the casein in a fluid suspension provided in step a). Caprine cream or milk fat from caprine cream, or a fraction thereof can also be used to impart a more distinct buttery flavour. A combination of fat from caprine or sheep milk and cow milk can also be used.

The fluid suspension provided in step a) comprises solid fat. For an advantageous rebodying, usually at least about 80 wt.% of the fat is solid, in particular crystalline, before the start of step b), in particular 90-100 wt.%, more in particular 95- 100 wt.%. In an embodiment, the fluid suspension is provided (e.g. purchased) as such. In case, a fluid suspension comprising dairy fat and micellar casein has a lower solid fat content prior to step b) than desired for a specific application, said suspension is first subjected to a fat solidification step, generally comprising a reduction of temperature until the intended solid fat content (usually at least about 80 wt.%) is reached. A suitable temperature and duration can be determined empirically. As a rule of thumb, the higher the content of unsaturated fatty acids and/or relatively short chain fatty acids the lower the preferred temperature is. Usually, a fat solidification prior to step b) is carried out at a temperature in the range 0-20 °C, preferably at a temperature in the range of 0-10°C, in particular at a temperature of 2-6 °C. In particular good results have been achieved at a temperature of about 5 °C. Depending upon the initial solid fat content, the target solid fat content and the temperature, a preferred duration can be at least about 1 hour, at least about 5 hours, at least about 10 hours or more, e.g. up to 24 hours, up to 48 hours.

Further, in particular when starting from cream or another suspension with a relatively low fat content the provision of the fluid suspension in step a) can comprise a concentration step. Concentration can be accomplished in a manner known per se, e.g. by vacuum evaporation, preferably at a temperature wherein all or at least most of the fat has melted, typically a temperature in the range of about 35 to about 60 °C, preferably about 40 to about 50 °C.

Furthermore, it is possible to prepare a fluid suspension comprising solid fat from a suspension that is essentially free of solid fat, by allowing a sufficient part thereof to solidify (crystallise). E.g. the fluid suspension may have been subjected to a heat treatment such as pasteurisation. Apart from a positive effect on microbiological quality, starting from a heat-treated, e.g. pasteurized fluid suspension— in particular a dairy cream - wherein at least 80 % of the fat is solidified may have a positive effect on reaching a desired viscosity increased in step c). Without being bound by theory, it is thought that this may be caused by changes in the milk fat globule membrane (MFGM). including denaturation and interaction with serum proteins, by sulphydryl-disulphide crosslinking reactions. Also casein micelles can associate with the MFGM by disulphide bonding between κ- casein and MFGM components, after heat treatment. This means that casein aggregates could interact with fat granules. A highly packed system is created with two types of particles, fat granules and protein aggregates, which might also be able to interact to a certain extent.

In step b) the temperature of the fluid suspension comprising solid fat provided in step a) is increased. Temperature and duration are chosen such that a part of the solid fat melts. It is important for rebodying that a part of the fat remains solid. The solid fat provides solid nuclei (usually fat crystals) which in step c) grow (usually comprising fat crystallisation) to form larger particles, which contributes to the formation of the solid food composition. For advantageous rebodying, at the end of step b) the solid fat content is usually at least 1.0 wt. %, preferably at least 1.5 wt. %, more preferably at least 2.5 wt.%, based on total fat. Usually, for advantageous rebodying, at the end of step b) the solid fat content is 10 wt.% or less, preferably 8 wt.% or less, based on total fat.

Usually, as described in further detail elsewhere herein, during step b) coagulation of casein takes place.

The temperature is usually increased in step b) to a value of at least about 30

°C. This is desired to allow efficient melting of a sufficient part of the solid fat, at least within a reasonable time span and for efficient coagulation, especially in case of enzymatic coagulation. A temperature in excess of 40 °C is generally not needed. It should be noted that in particular, in case the fat phase has an end melting point that is above the end melting point of milk fat, a higher maximum temperature may be employed in step b), typically of up to about 45 °C. In case the fat phase has about the same end- melting point or a lower end- melting point than milk fat, one may in principle still expose the suspension during step b) to a temperature above 40 °C, provided the duration is sufficiently short to avoid melting of too much solid fat.

Good results have been achieved with a method wherein the temperature during step b) is in the range of 32-38 °C, in particular in the range of 34-36 °C, especially in an embodiment wherein the fat at least substantially consists of bovine milk fat. A lower temperature may be employed, generally at a longer holding time at increased temperature, or a higher temperature at a shorter holding time at increased temperature. For an embodiment wherein the fat essentially consists of caprine milk fat, the temperature during step b) is preferably in the range of 20-35 °C, more preferably in the range of 22-28 °C. A lower temperature may be employed, generally at a longer holding time at increased temperature, or a higher temperature at a shorter holding time at increased temperature. For a blend of milk fat from two or more different sources, the skilled person will be able to determine a particularly suitable temperature and duration based on the information disclosed herein, common general knowledge and optionally a limit amount of routine testing.

A suitable duration of step b) can be determined routinely, based on common general knowledge and the information disclosed herein, taking into account the desired solid fat content at the end of step b). The duration of step b) is usually at least about 0.5 hr, preferably at least 1.5 hrs, in particular at least 2.0 hours. The duration in step b) is usually about 4 hrs. or less, preferably about 3 hrs or less, in particular about 2.5 hrs or less. As explained hereinbefore, step b) is generally carried out without subjecting the suspension to substantial shearing (such as e.g. stirring). Depending on total fat content of the fluid suspension resulting from step (a) the fluid suspension may be stirred or otherwise be subjected to shearing during step (b) to stimulate partial coalescence of the fat globules which, as explained above, causes the rebodying of the fat. Generally, however, a total fat content of 20 wt.% or more should be sufficiently high to achieve rebodying of fat without any shearing in step b). Advantageously step b) is carried out in a (consumer) packaging, which is preferably sealed.

After a sufficient part of the solid fat has melted (usually at a point wherein the solid fat content is in the range of about 1 to about 10 wt.% based on total fat) the resultant fluid mixture is subjected to a fat solidification step. The result fluid mixture comprises solid fat particles (nuclei) which are allowed to grow, due to solidification (such as crystallisation) of liquid fat on the solid fat particles. This is generally accomplished by reducing the temperature of the mixture (which is still a fluid suspension). In principle temperature reduction may be initiated before coagulation of the casein as long as a satisfactory casein coagulation has been achieved before the mixture becoming a solid, but as also can be concluded from the remainder of the disclosure, it is generally preferred that first a casein coagulation is carried out and thereafter the fat solidification step c) is proceeded with.

The cooling from the relatively high temperature at the end of step b) to the lowest temperature reached in step c), can but does not need to be controlled. Good results have been achieved by placing the fluid mixture obtained in step b) in a refrigerated room.

The inventors further found that the time needed for the fluid mixture obtained in step b) to cool from the high temperature at the end of step b) to the lowest temperature reached in step c), has an effect on firmness/spreadability of the obtained solid food composition. Several experiments were performed to investigate this. E.g. in an embodiment wherein the temperature was reduced by about 30 °C (from about 35 °C to about 5 °C), better results where obtained at a relatively low cooling rate (about 100 min to essentially reach end temperature) than at a relatively high cooling rate (about 10 min to essentially reach lowest temperature in step c). Taking the findings of these experiments into account, the average cooling rate to essentially reach the lowest temperature in step c) is usually about 3 °C/min or less, in particular about 1.0 °C /min or less, preferably 0.6 °C /min or less, more preferably 0.5 °C /min or less. The lower limit is usually determined by an acceptable duration of step c), taking into account maintaining microbiological quality and production capacity. Accordingly, in practice, the average cooling rate is usually chosen to be such that the cooling is effectuated within 48 hours, in particular within 24 hours, preferably within 12 hours, more preferably within 6 hours. In terms of average cooling rate, the average cooling rate usually is at least 0.01 °C/min, preferably at least 0.04 °C/min, more preferably at least 0.1 °C/min.

The average cooling rate may be determined as [(Temperature at the end of step b) - (Lowest temperature in step c)]/time needed to reduce temperature from Temperature at the end of step b) to Lowest temperature in step c).

A method according to the invention may further comprise the addition of one or more optional ingredients. These are usually added prior to solidification of the food composition in step c). E.g. an aroma component may be added. For example a fruit flavour, a chocolate flavour or a vanilla flavour may be added. Further a sweetener may be includes, e.g. a sugar, a sugar alcohol or a high-intensity sweetener. Furthermore, a vitamin or other component having nutritional value may be added (e.g. a mineral, antioxidant, prebiotic oligosaccharide). . Suitable amounts may be based on what is generally known in the art or the citations mentioned herein about additives for butter- substitutes. Usually, the total concentration of components other than protein, fat and water of a composition, suspension or mixture (used) in accordance with the invention is 0- 20 wt.%, based on total weight, preferably 0-10 wt.%, in particular 0-5 wt.% . It is contemplated though that dietary fibre, such as inulin, may affect firmness and/or spreadability of the product. A thickening agent, e.g. starch or a dietary fibre with thickening properties may be employed if firmness of s specific composition is found to be unsatisfactory. Good results have been achieved with a food composition without added dietary fibre (other than prebiotic oligosaccharides naturally found in milk) or thickening agent. In particular from an olfactory perspective (e.g. flavour) , a

composition that is essentially free of non-dairy prebiotics and thickening agents is preferred. Further, good results have been achieved with a food composition that is obtained without adding any emulsifiers to the fluid suspension from which it is made. In as far as emulsifiers are used, these are typically emulsifiers naturally present in milk. Thus, usually a food composition according to the invention is essentially free of non-dairy emulsifiers. Apart from having a function in the final product (the solid composition), an ingredient may be added as a processing aid.

In particular, a (salt of) a divalent cation, preferably magnesium or calcium, has been found to be advantageous when added to a fluid suspension in a method step of the invention. The divalent cation may be added in any form suitable for use in food products. Preferably it is added as an inorganic salt. It was found that addition of such cation is useful to increase firmness. Particularly good results have been achieved with a chloride salt, such as calcium chloride. If present, the concentration usually is in the range of 0.1-100 mmol/1, preferably in the range of 1-90 mmol/1, in particular in the range of about 10 to about 40 mmol/1. Preferably, the divalent cation is added before step b) or during step b).

The method of the present invention as described above and as exemplified in the Examples results in a dairy food composition, which is (at 20 °C ) a solid suspension of the oil-in-water type

The present invention further relates to a diary food composition. The food composition can e.g. be prepared by a method as described herein. Preferred preferred contents generally correspond to those given for the fluid suspension provided in step a) or obtained as an intermediate mixture in step b) of a method according to the invention.

A dairy food according to the invention is solid at 20°C. At least if it is intended for use as a spread, e.g. on bread or toast, it is usually spreadable at 15 °C, and preferably at 4 °C.

The food composition according to the invention comprises 1-6 wt. %, preferably 1-4 wt. %, in particular 1-3 wt. % dairy protein. Usually casein is the major protein (>50 wt.% based on total protein) or only protein present. The presence of protein, in particular coagulated casein, contributes to firmness.

The fat content is generally in the range of 20-70 wt.%. Usually 50-100 wt.%, preferably 90-100 wt.% of the fat is dairy fat, e.g. milk fat or a blend of milk fat and a specific milk fat fraction (e.g. a stearin fraction). Fat contributes to firmness of the composition. Accordingly the fat content preferably is 25-55 wt.%, in particular if the protein content is 4 wt.% or less. More preferably the fat content is 30-55 wt.%. For a satisfactory firmness in combination with good spreadability at a relatively low temperature (at 15 °C, suitably at 10 °C or less, in particular at 4 °C) a fat content of 38- 45 wt.% has been found particularly suitable. Particularly good results, in terms of firmness, spreadability and a butter-like taste have been achieved with a food composition wherein the fat fraction

The water content is determined by the amount of total other ingredients. In addition to protein and fat, one or more other ingredients as described above may be present in the food composition. The water content generally is in the range of 20-79 wt.%, preferably 40-60 wt. % water, more preferably 45-55 wt.% water.

In a highly preferred embodiment, the food product according to the invention comprises

1.5-3.0 wt.% casein;

35-50 wt. % milk fat, preferably 38-45 wt.% milk fat;

45-55 wt. % water; and

0-10 wt.% other ingredients.

For easy spreading at a certain temperature, the food composition should not have too high a firmness. For instance, regular butter general has a firmness at 15 °C in the range of 0.4-1 N. This is rather high, especially if it is to be spread on a soft product, e.g. bread. Accordingly, usually, a solid food composition according to the present invention, and least when it needs to be suitable for use as a spread, has a firmness of 0.4 N or less. If the product is intended for another application, a relatively high firmness, in particular of up to about 1 N may be acceptable or even desirable. A too low firmness, on the other hand, may be undesired e.g. because the composition may melt if exposed to a slightly higher temperature than ambient temperature (e.g. slightly above 20 °C), or undesirably penetrate into a product on which it is applied. Accordingly, generally the firmness of a composition according to the invention at 15 °C is 0.05 N and typically at least about 0.10 N. Further, it has been found that many consumers appreciate a composition with a moderately high firmness from a sensorial perspective (e.g. mouthfeel).

Preferably, the solid food composition has a firmness at 15 °C in the range of 0.12-0.30 N. Such product has good spreadability in combination with satisfactory firmness, e.g. for use in a spread application. Such solid food composition may for instance be obtained using dairy cream as the sole or major source of protein and fat, in which case a particular strong olfactory resemblance with butter is experienced. More preferably, the firmness is 0.12-0.26 N. In particular good results in terms of spreadability and sensorial appreciation have been obtained with a composition having a firmness of 0.15-0.26 N, in particular 0.15-0.20, also at a temperature below 15 °C, e.g. at about 4 °C.

The pH of the solid food composition is usually about neutral (pH 7.0) or less. Usually, the pH is at least about 4.0. Preferably the pH is in the range of 4.5-6.8. A more acidic composition tends to be more firm, at the same protein and fat composition.

Next, the invention will be illustrated by the following Examples.

Example 1 A spreadable dairy product with a buttery taste was prepared as follows.

A dairy cream (bovine) was stored at 4 °C. To this cream rennet was added at a temperature of 4 °C. Thereafter, calcium chloride was added (also at 4 °C).

The resultant fluid suspension, comprising micellar casein and solid milk fat thus provided (step a), was divided over a plurality of containers which were placed in a storage room having a temperature of 40 °C for 2-4 hrs (step b). Some of the containers were removed from the storage room after 2 hours, others after 4 hours. Of these removed containers, some were placed in a refrigerated room at 4 °C and others in a refrigerated room at -2 °C. They were allowed to stand there overnight (step c). The next day the resultant products were evaluated. The containers kept in the storage room at 40 °C for 2 hours and subsequently subjected to cooling at 4 °C contained a solid food composition which was spreadable at a temperature of 4 °C and higher, at least up to about 20 °C. The containers that had been kept at 40 °C for 4 hours and/or that were stored at -2 °C did not contain a composition with a spreadable texture. Instead the suspensions in those containers remained fluid.

The difference between the samples that had been kept in a storage room having a temperature of 40 °C for 2 hours and the samples that had been kept in there for 4 hours was understood to be caused that the duration of 2 hours was insufficient to melt all fat in the sample, whereas after 4 hours all fat had melted. Thus, in the latter case no rebodying took place upon cooling.

Example 2

Based on the results described in Example 1, various method parameters were evaluated as described below. Materials

Bovine Cream (38 - 45 wt% fat, about 2 wt.% protein, of which about 80 wt. % micellar casein) (FrieslandCampma, Rijkevoort, Netherlands), Caprine Cream (~40 % fat) (Rouveen Kaasspecialiteiten, Rouveen, Netherlands), MCI80 liquid and powder (FrieslandCampma, Lochem, Netherlands), Kalase rennet (CSK, Leeuwarden,

Netherlands), STI-06 Culture (Chr Hansen, Horsholm, Denmark), CaCl2 35% solution (FrieslandCampma, Wageningen, Netherlands), Brine (FrieslandCampma, Wageningen, Netherlands), HCl solution (1 M), Annatto (CSK, Netherlands), Nile Red and Fast Green (Sigma-Aldrich, Schnelldorf, Germany), Fast Green (Sigma- Aldrich, Schnelldorf, Germany) were all used as received or diluted if necessary.

Production methods If desired, cream was first concentrated (e.g. to provide a fluid suspension having a fat content of more than 45 wt.%) was first transferred to a rotary evaporator and a pump was started to bring the system under vacuum (-0.95 bar). Simultaneously, the sample was warmed to and kept between 40— 50 °C. After concentrating the cream from 46 % to 60 % dry matter, the evaporator was stopped to prevent phase separation. The cream was transferred to the cooling chamber and stored overnight at 5 °C. Thus, a fluid suspension comprising solid fat in an aqueous phase was provided in accordance with step a) of a method according to the invention.

The cream was stored for at least 12 hours at 5 °C in a cooling chamber to provide the fluid suspension with a solid fat content of at least about 80 wt.% (step a) and then taken out of the cooling chamber.

In some experiments additional MCI was added to the cream. For these experiments the cream was weighed in buckets and transferred to a water bath. The cream was warmed to 60 °C while stirred at a rate of 6 rpm with a Heidolph RZR 2101. 2.47 % (w/w) MCI powder (81 % protein) was added gradually to increase the cream protein content (from 2 % to 4 %). After complete dissolution of the MCI, the cream was transferred to a cooling chamber and stored overnight at 5 °C. MCI enriched cream was mixed with regular cream (that had been stored at 5 °C overnight) in different ratios before further treatment to obtain a solid food composition according to the invention. After storage at 5 °C (to provide the fluid suspension comprising solid fat of step a)) the cream was weighed and inoculated with Kalase to provide 60 IMCU/1) cream, unless specified otherwise. If included to the experimental design, CaCl2 was added at this stage.

The suspension was stirred to distribute the rennet and any other components. Each sample was produced in quadruplicate by distributing the suspension over four 125 mL cups (i.e. 500 mL for each process variable). Then the cups comprising the fluid suspension comprising solid fat were sealed with an ILPRA termosaldatrici (Induquip, Wapenveld, Netherlands) and transferred to a water bath. The samples were warmed for 150 minutes at 35 °C, unless specified otherwise (step b).

Finally, the samples in the cups were transferred to the cooling chamber and stored for at least 12 hours at 5 °C, unless specified otherwise (step c).

Analytical methods

Confocal Laser Scanning Microscopy ( CLSM)

CLSM (Leica TCS SP5, Leica Microsystems Ltd.) was used to study the microstructures of obtained food compositions. The samples were stained with Nile Red and Fast Green to visualize the fat and protein respectively. An Argon laser (excitation wavelength of 488 nm) and a Helium-neon (HeNe) laser (633 nm) were used. Nile Red was detected between 575 and 625 nm and Fast Green between 640— 740 nm. The lOx, 20x and 63x objective lenses were utilized for different magnifications and the images obtained had a resolution of 1024 x 1024.

Temperature data logger

The temperature of the cream upon cooling was recorded in order to study the effect of cooling rate. An Ecograph T RSG35 (Endress & Hauser, Naarden, Netherlands) was used in combination with 4 PT100 probes. The probes were placed in the middle of the samples and the temperatures were tracked over time.

Particle Size Distribution

Particle size distributions were measured with a Mastersizer 2000 (Malvern, Worcestershire, England), combined with a Hydro 2000MU wet dispersion unit, using laser diffraction. The refractive index for cream was set to 1.462, the absorption to 0.01 and the dispersant was water (RI 1.33). The Sauter mean diameter (D 3,2) was calculated by the Malvern Software.

Spreadability

An MCR 302 rheometer (Anton Paar, Graz, Austria) was used to determine the viscosity of the obtained food compositions as a function of shear rate. An MCR 302 rheometer was used with a concentric setup to determine the viscosity. Prior to the actual measurement, the samples were allowed to reach the starting temperature by remaining 5 minutes in the concentric cylinder. The rheometer temperature ramp was set to 5— 50 °C with a rate of 0.5 °C / minute. The strain was set to 0.01 and the frequency 1.000 Hz. The machine software calculated the complex viscosity from the measured data.

The temperature of the rheometer was set to 15 °C and the food composition to be evaluated was spooned to a plate (TEK P/MCl-80). The probe (PP25, d = 24.95 mm) was lowered to the trim position and redundant composition was then removed from the plate. Then, the probe was further lowered to its measuring position (2 mm) and the sample was allowed to attain the measuring temperature (15 °C) by resting for 1 minute. The shear stress linear ramp was set to 0 - 750 Pa in 90 seconds. The viscosity as function of shear stress was calculated and graphically shown by the machine software. All samples were measured in duplicate.

Texture Analysis

Sample pretreatment: A square mould was filled with sample by pressing it in the food composition. After taking out the mould from the sample, redundant food composition was removed with a putty knife to obtain a smooth surface in the square mould. The square moulds with sample were put in a box and transferred to a water bath (15 °C). They remained in the water bath for 2— 3 hours to ensure a temperature of 15 °C and by that exclude any effect of temperature on the firmness of the food composition.

Analysis: The firmness of the composition was measured with a wire cutter probe attached to a ΤΑ-ΧΤ2Ϊ (Stable Micro Systems, Godalming, England) with a load cell of 50 kg. The trigger force was set to 0.04 N and the test speed 0.20 mm/s. The total penetration distance of the probe through the sample was 18.0 mm. The force (N) required to press through the sample between 7 and 14 mm penetration was averaged and gave the firmness of the composition.

Results and discussion

It was found that heating the suspension (based on bovine cream) having a solid fat content of at least 80 %, based on total fat in step b) from 5 °C to 35 °C (until solid fat content was reduced to a value in the range of about 1.5 to about 8 wt.% based on total fat and cooling it back to 5 °C (step c)) , resulted in a strong viscosity increase. In combination with the coagulating of casein this resulted in a solid composition with good spreadability.

However, in experiments wherein step b) was carried out at 40 °C (till essentially all fat had melted) subsequent cooling did not result in a strong viscosity increase, and the obtained composition did not sufficiently solidify at 5 °C. It was concluded that for a suspension having this specific composition, the maximum temperature in step b) should be lower and/or duration of step b) should be shorter.

In a comparative experiment, the effect of added protease (rennet) was investigated by comparing the firmness of the obtained food composition after the treatment at subsequently 5 °C, 35 °C and again 5 °C with and without rennet. Without rennet, a firmness of 0.076 N was reached, while in the composition obtained after rennet addition the firmness was 0.16 N. CLSM images revealed clear differences between the food composition obtained after step c) with and without casein aggregation (Figures 1 and 2). The image of the composition without rennet addition (Figure 1) shows fat granules (dark grey) in a continuous aqueous phase with proteins dissolved (off- white). Casein aggregates are clearly visible after rennet addition (Figure 2). Casein micelles are not dissolved anymore and their effective size have increased after aggregation. The CLSM image shows that fat granules and casein aggregates are well distributed throughout the composition The viscosity increase after aggregation of casein is thought to be a consequence of a highly packed system, causing the composition to be solid.

Next, a variety of product and process variables were tested and related to physical properties of the solid food composition. E.g. fat content and warming maximum temperature during step b) had a major impact on the structure of solid composition, whereas other factors showed smaller or more specific effects (e.g. on spreadability). Fat content

The effect of fat content on the firmness, spreading properties and structure was studied. For compositions made from bovine cream (wherein the fat phase consists of milk fat, and all protein is milk protein present in the cream), wherein the highest temperature reached in step b was 35 °C a fat content of 25 wt.% or less resulted in a thick viscous fluid. A higher fat content, in particular starting from about 35 wt. % up to 53 % fat resulted in increased firmness, whilst maintaining satisfactory spreadability, and without substantial risk of visual phase-separation.

The firmness and spreadability (using viscosity when applying shear stress as a measure) of the food composition was measured as a function of fat content. The area under the curve, with viscosity (kPa.s) on the y-axis and shear stress (kPa) on the x-axis, was calculated and expressed in kPa 2 .s. This calculated number represents the accumulated viscosity after applying shear stress, considering both the peak viscosity and the shear stress required to nullify the viscosity. The force (i.e. firmness) and the surface under the curve (as a measure for resistance against spreading) are shown in Figure 3. The dashed line represents the estimate interparticle space in μπι. The firmness and spreadability increased strongly with an increasing fat content. The surface under the curve decreased slightly when the fat volume fractions exceeded 0.5. This is because the peak viscosity is lower, even though the shear stress required to nullify the viscosity is higher.

Figure 4 shows the effect of milk fat content of bovine dairy cream (providing the fluid suspension in step a) of a method according to the invention) on the firmness of the obtained product (after treatment in step b) at 35 °C (for 150 min) and cooling to 5 °C in step c) ).

Warming temperature (step b)

The effect of the temperature increase during step b) to a temperature in the range of 33 - 39 °C was studied with an interval of 2 °C using a water bath. The resulting force and area under the curve are shown in Figure 5. It can be concluded that for the tested compositions based on bovine cream, a holding temperature of 35 °C was optimal in providing firmness to the obtained solid food composition. Cooling rate (step c)

Four sets of samples were made, one was cooled in a cooling chamber and the others were cooled in a water bath at different cooling rates. The temperatures were monitored and average cooling rates were calculated. The results are shown in Figure 6.

It can be seen that both at a relatively high cooling rate and at a relatively low cooling rate a solid composition is obtainable. From the results it is concluded that cooling rate can be used to adjust firmness of the solid product to be prepared. In particular, it is concluded that a lower cooling rate generally contributes to an increased firmness.

Content of micellar casein I

The presence of casein aggregates significantly affects the firmness and spreading properties of the food composition.

It was found that addition of MCI to cream, prior to step b) contributed to the firmness of the food composition, particularly in the range of 2.0 % to 2.5 % (w/w) protein (in addition to casein already present in the cream). At higher concentrations, only a small increase in firmness was observed.

The following Table shows shear stress required to nullify the viscosity of a food composition according to the invention with different protein content:

It was found that the shear stress required to make the material flow increases with increasing protein content. For most parameters, an increased resistance against spreading was found to be mainly a consequence of an increased firmness.

Increasing micellar casein content was found particularly useful to provide a product with altered stress required to nullify viscosity, with a relatively low change in firmness. CaCl2 addition

Adding calcium to the cream lowered the pH. The reason for that is considered to be as follows: there is more Ca 2+ available to bind to phosphate . When all phosphate is bound in micelles and present as colloidal calcium phosphate (CCP), pH decreases and the remaining calcium is present as calcium ions in the aqueous phase. Hydrolysis of κ-casein is accelerated, but even at constant pH the rennet coagulation time (RCT) would be reduced upon addition of calcium. Up to 10 mmol CaC / 1 milk, the casein gel strength already increases. Further increase (< 50 mmol / L milk), results in earlier flocculation and an increased rate of firming of casein gels. Addition of calcium in high concentrations (> 100 mmol / L milk) leads to a reduced rate of gel firming.

It was found that addition of CaCl2 enhanced the firmness of the food composition to a certain extent. Up to a concentration of about 0.4 % (w/w) CaCk or 34 mmol/1 there was an increase in firmness, where after the firmness slightly decreases again. This is more or less in line with the previously described effect of calcium addition in milk, when considering that cream contained only 2 % protein instead of 3.5 % protein in milk. Between 10 and 50 mmol/1 milk there is earlier flocculation and an increased rate of firming, which equals ~ 5.6— 28 mmol /l cream, if only considering the number of moles of CaCl2 / g protein. The highest concentration tested was 1 % (w/w) CaC12 or 90 mmol/1. This exceeds 56 mmol /l, which is expected to be the concentration after which the rate of gel firming reduces in cream. Accordingly, there is a small decrease in firmness of the food composition. An additional side effect of CaCl2 addition in high quantities was a bitter taste. A bitter taste was sensorial observed at the highest concentration (1 % or 90 mmol /l).

Overall, it can be concluded that small concentrations (< 0.4 % w/w) enhances the firmness and resistance against spreading. Higher concentrations seem to have a slightly negative effect on the firmness, probably caused by an increased positive charge and accordingly, electrostatic repulsion in and between casein micelles. The effect of CaCl2 on the spreading properties is comparable to the effect of MCI addition. Generally, the shear stress required to nullify the viscosity of the product increases with an increased CaC addition. The conclusion can be drawn that influencing the protein fraction, either through MCI addition or CaC addition, provides an opportunity to alter the spreading properties of the food composition according to the invention . Rennet concentration

For this experiment a broad range of 4— 480 IMCU / 1 was tested. Figure 7 shows the resulting firmness and resistance against spreading as a function of the rennet concentration. The firmness was only significantly affected at very low rennet concentrations (0— 8 IMCU / 1). Both the force and the area under the curve show a peak at -30 IMCU / 1).

Warming time (step b)

The warming time (duration of step b) affects both the extent to which the fat crystals are molten and the κ-casein hydrolysis (and thus casein aggregation). It is expected that after a certain time there is no effect when holding the cream at its warming temperature any longer. This point in time is reached after sufficient melting of fat crystals and sufficient κ-casein hydrolysis.

Overall, an increased firmness was found with an increasing warming time. However, the differences were small in comparison to the effect of other variables.

Replacement of bovine cream by caprine cream

The composition and the physico-chemical properties of caprine dairy differ from bovine dairy in some crucial aspects. The ratio casein to whey protein is smaller in caprine dairy (7:3) than in bovine dairy. Caprine dairy contains less as- casein than bovine dairy and it contains more as2 than asl-casein. Due to differences in casein proteins and micelle structure, the renetting time for caprine milk is shorter and the consistency of casein gels is usually weaker .

After centrifugation, the fat content of caprine cream is more or less equal to the fat content of bovine cream, but caprine fat globules have a smaller average diameter (3.49 μπι) than bovine cream (4.55 μπι). The fat globule size influences fat crystallization and probably rebodying. Another relevant difference is the lack of agglutinin in caprine dairy, a component responsible for clustering (agglutination) and creaming of fat in bovine dairy. It is expected that agglutination of fat in bovine cream promotes partial coalescence through rebodying. The fat globules are already clustered by agglutinin and as a result, protruding crystals may easily pierce surrounding fat globules. Presumably, the absence of agglutinin and a smaller average globule size decreases the chance of fat globules meeting each other and thus the chance on partial coalescence through rebodying in caprine cream. It was therefore expected that rebodying of fat would be less or absent in caprine cream.

Bearing these initial considerations in mind caprine cream (42.79 % fat) was successfully used for the preparation of a solid composition according to the invention. The firmness of the composition prepared from caprine cream was 0.152 N, which is about as firm as a composition prepared from bovine cream (42.77 % fat) , of which the firmness was 0.155 N. The main difference (except from the source), was the warming temperature. The melting range of caprine fat is different from bovine fat and the optimum warming temperature was found to be 25 °C. When warming to 35 °C, the resulting caprine Dream Cream was very soft. Although there is a lack of studies showing SFC curves for goat fat, it can be found that goat and sheep fat melts at lower temperatures than for example cow and camel milk fat .

Figure 8 shows the firmness of a food composition made from caprine cream after step c) prepared from raw cream, pasteurized cream or pasteurized cream with calcium (0.175 %). Warming the cream to 25 °C led to a significant higher firmness than warming it to 35 °C. Considering the fact that the product was still a solid after warming at 35 °C, indicates that not all fat crystals are molten. Another important result is that the pasteurized cream led to a significantly firmer product than the raw cream.

The different solid food compositions prepared from caprine cream were studied with CLSM. The obtained images did not reveal major structural differences between the composition obtained from raw and pasteurized caprine cream.

Acid coagulation

Casein aggregation was achieved by adding rennet, but could also be achieved through acid coagulation. When altering the pH towards the pi of casein (~ 4.6), texture analysis showed that when applying acid coagulation instead of rennet-induced coagulation the firmness was around 1.5 times higher. The firmness for acid and rennet- induced coagulation were 0.209 N and 0.140 N respectively. CLSM images showed a similar structure for both types of casein aggregation. No differences in syneresis were observed between rennet coagulated and acid coagulated product.

The combined effect of acid coagulation and addition of calcium was also tested. The results clearly showed that the firmness and resistance against spreading decreased with an increasing calcium content. CLSM images were also made. The images indicated a decrease in casein aggregate size with increasing calcium concentrations.

Concluding remarks

Regarding firmness, it can be concluded that a relatively high firmness was considered most pleasant from a sensory perspective. However, in order to achieve a high firmness (of about 0.26 N or higher) a relatively high fat content was used. In order to achieve a firmness of 0.17 N (considered an '8 out of 10' in sensory liking), a fat content of 43 % would be sufficient. If a higher firmness is desired, an alternative for increasing the fat content would be to increase the protein fraction from 2 % to 4 %. This resulted in a firmness of 0.25 N in a bovine dairy cream with 42.8 % fat.

Regarding spreadability, at low fat concentrations, the products made from cream without protein addition had a poor spreadability because the samples were very soft. At higher fat concentrations (> 43 % fat) the spreadability was good, but the sample started to curl up upon spreading at very high fat content. The optimum spreadability was obtained in a range of 40— 45 % fat (milk fat) .

Example 3

Example of method to obtain a solid food composition with particular good firmness, spreadability and olfactory appreciation (in terms such as mouthfeel and a butter-like taste), based on findings in Example 2

Fat content 43 wt.% (milk fat)

Protein content 2 wt% (milk protein)

Dry matter 48 wt.%

Rennet addition 30 IMCU / L (0.02 % Kalase)

Additives 0.1 % (w/w) potassium sorbate *

Process

Cooling prior to warming (step a) >1 h at 5 °C (e.g. about 12 hours)

Warming (step b) 150 min at 35 °C

Cooling rate (step c) 0.3 °C / min

Cooling after warming (step c) 12 h at 5 °C **