GB2158452A

GB2158452A - Fat-continuous emulsions and spreads

Info

Publication number: GB2158452A
Application number: GB08512029A
Authority: GB
Inventors: Douglas Chater Kirton; Avril Brown Macneill
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1984-05-11
Filing date: 1985-05-13
Publication date: 1985-11-13
Also published as: GB8512029D0; GB2158452B

Abstract

Fat continuous emulsions having a reduced fat content are produced from a proteinaceous aqueous phase containing buttermilk constituents and a fat phase containing a quick crystallizing fat having a melting point ranging from 30 to 60 DEG C such as hydrogenated palm-kernel, rapeseed or coconut fat. The fat phase preferably also contains (a) a liquid oil such as soyabean oil (b) an interistified mixture of palm oil and palm-kernel oil and (c) butterfat and the aqueous phase preferably also contains sodium caseinate. The emulsion is preferably produced by (1) preparing a cream of water, buttermilk and the crystallising fat, (2) preparing an aqueous phase of water and protein, emulsifying (2) with a fat phase preferably containing (a), (b) and (c) and then mixing the product with (1).

Description

SPECIFICATION Fat-continuous emulsions and spreads having a reduced fat content The present invention relates to fat-continuous emulsions of the water-in-oil type and of the oilin-water-in-oil type (w/o and o/w/o emulsions) and spreads having a reduced fat content.

By reduced fat content is meant a fat content of 25 to 75%, which is lower than the fat content of conventional margarines (which is approximately 80 wt.%), preferably a fat content ranging from 30 to 65 wt.%, and most preferably a fat content ranging from 35 to 50 wt.%.

There is need of low-fat spreads displaying pleasant organoleptic properties,which are considerably cheaper than dairy butter and can be produced by a continuous, industrial process.

Applicants have found a judicious combination of formulation criteria and processing conditions conducive to low-fat spreads having organoleptic properties comparable or even superior to those produced from cultured ingredients (e.g. using lactic acid bacteria).

The fat-continuous emulsions and spreads having a level of fat ranging from 25 to 75 wt.% according to the invention comprise: (i) a proteinaceous aqueous phase containing buttermilk constituents, and (ii) a fat phase comprising a fat blend containing, as one of the fat components, a quick crystallizing fat having a melting point ranging from 30 to 60"C, selected from the group consisting of hydrogenated palmkernel, coconut, babassu, ouricurum, murumuru, tucum and cocoabutter fat, cocoabutter substitutes and oils consisting of triglycerides from fatty acids in the trans-configuration.

The aqueous phase preferably constitutes the dispersed phase of the emulsion.

The quick crystallizing fat should be present in the dispersed, aqueous phase, but can be present both in the dispersed phase and in the continuous fat phase and preferably constitutes 1 to 20 wt.% of the total amount of fat. The quick crystallizing fat has preferably a melting point ranging from 35 to 50'C and ideally consists of substantially fully hydrogenated laurics and particularly palmkernel fat (m.p. 38"C) or coconut fat (m.p. 31"C).

Appropriate quick crystallizing fats may also consist of oils such as sunflower, safflower, rapeseed, soy, maize, peanut, cottonseed oil and the like which have been hydrogenated under conditions promoting isomerism, whereby trans-fatty acids at a level preferably ranging from 30 to 70% are formed.

These conditions are well known in the art and involve e.g. hydrogenation at 1 40 to 180"C in the presence of a sulphur-poisoned catalyst such as nickel. The level of trans-fatty acids is measured e.g. according to A.O.C.S. tentative method Cd 14-16. Suitable quick melting fats may consist of cocoabutter substitutes such as those described in GB 1,390,936 inserted by way of reference.

The dispersed, aqueous phase preferably also contains butterfat, preferably at a level of 0.1 to 10% based on the weight of the emulsion, hydrogenated palm oil (m.p. 43"C) or fractions of palm oil such as a palm mid-fraction obtained by double wet fractionation (in the presence of an organic solvent), by double dry fractionation (in the absence of solvent) or by fractionation in an aqueous solution containing a detergent such as sodium dodecylsulphate.

It is, of course, possible to incorporate in the dispersed phase other fats, e.g. those which are used as components of the continuous fat phase of the emulsion.

Preferred emulsions contain in the dispersed, aqueous phase dissolved buttermilk solids at a level of 0.1 to 1 5 wt.% based on the total spread, and a secondary protein such as vegetable protein (e.g. soy protein) or a milk protein such as whey protein or sodium caseinate.

Preferably, a mixture of sodium caseinate and buttermilk powder is present in the dispersed, aqueous phase. The protein generally constitutes 0.1 to 15 wt.% of the total emulsion and preferably 5 to 25 wt.% based on the dispersed phase.

The dispersed, aqueous phase may contain, besides the phospholipids which are abundantly present in buttermilk. other emulsifiers such as a monoglyceride or a diglyceride.

In order to increase the stability of the emulsion, a viscosity-increasing agent or a gelling agent is used.

The aqueous phase preferably contains a viscosity-increasing agent, especially when low levels of protein are present. The viscosity-increasing agent may consist of a thickening agent such as gelatin, carboxymethyl-cellulose, pectin, agar, guar gum, xanthan gum or mixtures thereof.

The viscosity-increasing agent preferably consists of xanthan gum, since, when this is used, the viscosity of the aqueous phase remains independent of variations of the pH which may range from 3.5 to 6.5, but preferably is between 5.0 and 6.2. This pH is achieved by using, where necessary, an acid such as lactic acid.

The continuous fat phase of the emulsion can comprise vegetable fats, animal fats and fat replacers.

The vegetable fat may, for instance, consist of palm oil, soybean oil, rapeseed oil, cottonseed oil, maize oil, safflower oil, sunflower oil, lauric fats, etc., in hydrogenated or non-hydrogenated form.

The animal fat can, for instance, consist of tallow fat, lard, fish oil, butterfat and the like in hydrogenated or non-hydrogenated form.

The fat replacers may, for instance, consist of a sucrose polyester.

The above fats can also be used in the form of inter-esterified triglycerides.

The selection of specific fats and their relative proportions will depend on the requirements of the consumer, which may vary from country to country.

Appropriate fats for the continuous phase of the emulsion will generally display the following fat solids profile, measured by nuclear magnetic resonance as described in Fette, Seifen, Anstrichmittel 80, 180-186: Nio.c= 15-60; N2o.c= 10-35; N35.c 2.

This fat profile can be obtained by mixing appropriate proportions of fats such as those described above, and, if desired, by interesterifying the mixture thus obtained. Interesterification may involve random interesterification or directed interesterification, which means an interesterification combined with a crystallization of higher melting triglycerides which can be filtered off.

Preferably, random interesterification is carried out under substantially moisture-free conditions, under reduded pressure using an alkali metal oxide or dry sodium hydroxide.

The continuous fat phase preferably contains butterfat. Fat blends which have proved to be particularly suitable for producing the continuous phase of the emulsion consisted of (1) a liquid oil (which is substantially free from crystallized fats at 10"C), (2) a partially hydrogenated fat having a melting point ranging from 33 to 43"C, (3) an interesterified mixture obtained from palm oil and an oil selected from the group consisting of palmkernel, coconut, babassu, ouricurum and tucum oil, and (4) butterfat.

The emulsion according to the invention will generally contain emulsifiers such as mono/diglycerides, phospholipids, etc. Preferably distilled monoglycerides are used.

Whatever fat is used for producing the spread, it is important that one of the components of the total fat blend consists of a quick crystallizing fat. The quick crystallizing fat is believed to form a complex with the emulsifier, the protein present in the aqueous phase and possibly the stabilizer (gelling agent or viscosity-increasing agent), thereby forming rather stable fat globules.

As described further in the specification, the quick crystallizing fat is introduced into the dispersed, aqueous phase of the emulsion. It is believed that fat globules complexed with the emulsifier and protein formed in the aqueous phase migrate to the water/oil interface of the emulsion and possibly partly to the continuous phase, and influence the crystallization behaviour of the fat constituting the continuous phase of the emulsion.

The edible emulsions according to the invention are produced by a process comprising (a) producing an aqueous phase, constituting the dispersed, aqueous phase of the emulsion, from buttermilk constituents, water and a quick crystallizing fat having a melting point ranging from 30 to 60"C, selected from the group consisting of hydrogenated palm kernel, coconut, babassu, ouricurum, murumuru, tucum and cocoabutter fat, cocoabutter substitutes and oils consisting of triglycerides from fatty acids in the trans-configuration; and (b) emulsifying the aqueous phase thus obtained with a fat phase comprising the remaining components of the total fat blend.

The aqueous phase is preferably produced and emulsified with the fat phase at a temperature which is at least as high as the melting temperature of the fat.

It is recommendable to homogenize and deaerate the aqueous phase prior to emulsification.

A preferred way of carrying out the process of the present invention comprises (A) producing the dispersed, aqueous phase of the emulsion by (1) preparing a cream from water, buttermilk powder and the quick crystallizing fat, (2) preparing a proteinaceous aqueous phase, substantially free from fat, starting from water, protein and the minor ingredients; and (B) producing the final emulsion by first emulsifying the proteinaceous aqueous phase produced in (2) with the continuous fat phase to obtain a pre-mix, and subsequently mixing the cream obtained in (1) with said pre-mix.

Applicants have found that this way of carrying out the process according to the invention resulted in a more efficient use of the protein, i.e. the desired viscosity in the mouth can be achieved with less protein.

It is, of course, also possible to produce separately a cream and a proteinaceous aqueous phase which is free from fats as described above, subsequently to combine these and finally to emulsify the combined phases with a continuous fat phase.

Another very suitable way of carrying out the process of the present invention involves: (1) dissolving in water all the ingredients of the dispersed, aqueous phase except the quick melting fat and the emulsifiers, at a temperature which is at least as high as the melting point of the quick melting fat; (2) mixing the mixture obtained in (1) with molten quick melting fat; and (3) emulsifying the mixture obtained in step (2) with a molten fat phase containing the remaining components of the total fat blend, preferably along with an appropriate emulsifier such as a monoglyceride.

Steps (1), (2) and (3) are preferably carried out at a temperature ranging from 45 to 65"C.

Step (2) is preferably carried out applying homogenization under pressure (approximately 200 bar). The mixture obtained in (2) is preferably deaerated before performing step (3).

Reduced fat spreads according to the invention are produced by texturisation of the emulsions described above, by applying cooling and working in any of the apparatuses well known in the art, such as churning machines, VotatorsR, ComplectorsR, etc.

In the case where a fat-continuous spread with a relatively low level of protein, i.e. a level ranging from 0.1 to 10 wt.%, preferably 1 to 5 wt.%, is to be produced, a water-continuous emulsion is prepared from the cream, the proteinaceous aqueous phase and the fat constituting the continuous phase of the emulsion, and the o/w emulsion is subsequently caused to invert by cooling and working it, e.g. as described in US 4,362,758.

In the case where fat-continuous spreads with a relatively high level of protein are to be produced (i.e. levels ranging from 5 to 1 5 wt.%), a w/o emulsion is produced by emulsifying the cream and the proteinaceous aqueous phase into the continuous phase of emulsion and the w/o emulsion is cooled and worked in the usual way to obtain a spread.

Apparatus and methods for texturising emulsions by cooling and working are extensively described in Margarine by A.J.C. Andersen, second revised edition 1965, Pergamon Press, which is inserted by way of reference.

The invention will now be illustrated in the following Examples.

Example 1 A spread was produced from a cream phase, a proteinaceous aqueous phase and an oil phase of the following compositions: Cream phase Wt.% Water 8.6 Buttermilk powder 1.05 Monoglyceride 0.07 Xanthan gum 0.03 Palmkernel fat (m.p. 38on) 3.75 Whole butter 1.5 Aqueous phase Water (added to make) up to 100.00% Sodium caseinate 7.9 Buttermilk powder 1.5 Salt 1.5 Potassium sorbate 0.1 5 Lacetic acid (80%) 0.25 Oil Phase Oil blend 33.5 Distilled monoglyceride 0.2 Whole butter 1.5 The oil blend consisted of (a) 5% soybean oil (m.p. 38 C), (b) 24% of an interesterified mixture from 60 parts of palm oil and 40 parts of palmkernel oil, and (c) 4.5% soybean oil.

The above phases were prepared as follows: Preparation of the cream Xanthan gum and buttermilk powder were added to heated water (55'C) under vigorous agitation. Molten hydrogenated palmkernel fat (m.p. 38"C) containing monoglyceride as well as molten butterfat was added under agitation.

The mixture thus obtained was homogenized and pasteurized.

Preparation of the proteinaceous aqueous phase Potassium sorbate, salt, sodium caseinate and buttermilk powder were added to heated water (60"C) under agitation.

The proteinaceous aqueous phase was subsequently passed through a deaerator.

The proteinaceous aqueous phase was added to the oil phase, pre-heated to 60"C. The cream was subsequently added under constant stirring. The w/o emulsion obtained was then cooled and worked in a VotatorX apparatus. The spread obtained was submitted to a panel of experts who tested its spreadability on bread and the organoleptic properties in comparison with a similar product produced from cultured ingredients. t The spread was found very satisfactory.

Example 2 The general procedure of Example 1 was followed, with the following modifications: (a) instead of 7.9% sodium caseinate, 2.5% was used; (b) the spread was produced from an o/w emulsion, which was caused to invert by churning it in a rapidly rotating vessel under cooling as described in US 4362 758.

The spread obtained was submitted to the panel of experts who tested the plasticity and the organoleptic properties in comparison with a similar product produced from cultured ingredients.

The spread was found very satisfactory.

Example 3 An aqueous phase (constituting the dispersed phase of the emulsion, and an oil phase (constituting the continuous phase of the emulsion) of the following composition were produced: Aqueous phase wt.% Buttermilk powder 2.55 Xanthan gum 0.03 Sodium caseinate 7.9 (a) Salt 1.5 Potassium sorbate 0.1 5 Lactic acid (80%) 0.25 Water up to 100% Palmkernel fat (m.p. 38 ) 3.75 (b) Whole butter 1.5 Monoglyceride 0.07 Oil phase Oil blend of Example 1 33.5 Distilled monoglyceride 0.2 Whole butter 1.5 The dispersed aqueous phase was produced as follows: The ingredients under (a) were mixed at 60"C under agitation.

The ingredients under (b) in molten form were added to the mixture and the combined mix was homogenized under pressure and deaerated.

The deaerated aqueous phase was mixed with the oil phase at 60"C to form a fat-continuous emulsion of the o/w/o type.

Preparation of a spread The fat-continuous emulsion was worked and cooled in a VotatorX apparatus.

The spread obtained was submitted to a panel of experts who tested its spreadability and organoleptic propertie in comparison with a similar product made from cultured ingredients.

The cultured ingredients consisted of a protein concentrate derived from the culturing of buttermilk.

The spread was found as satisfactory as the product used for comparison.

Example 4 Example 3 was repeated, except that rapeseed oil (m.p. 40'C) hydrogenated using a sulphurpoisoned catalyst (level of trans approximately 60%) was used instead of hydrogenated palmkernel fat.

The spread obtained was as satisfactory as the product used for comparison.

Example 5 Example 3 was repeated, except that coconut fat (m.p. 34"C) was used instead of hydrogenated palmkernel fat.

The spread obtained was as satisfactory as the product used for comparison.

Claims

1. A fat-continuous emulsion having a level of fat ranging from 25 to 75 wt.%, comprising: (i) a proteinaceous aqueous phase containing buttermilk constituents, and (ii) a fat phase comprising a fat blend containing, as one of the fat components, a quick crystallizing fat having a melting point ranging from 30 to 60'C, selected from the group consisting of hydrogenated palmkernel, coconut, babassu, ouricurum, murumuru, tucum and cocoa butter fat, cocoabutter substitutes and oils consisting of triglycerides from fatty acids in the trans-configuration.

2. An emulsion according to claim 1, wherein the aqueous phase constitutes the dispersed phase of the emulsion.

3. An emulsion according to claim 1, wherein the dispersed, aqueous phase contains quick crystallizing fat.

4. An emulsion according to claim 1, wherein the quick crystallizing fat is present both in the dispersed phase and in the continuous phase.

5. An emulsion according to claim 1, wherein the quick crystallizing fat constitutes 1 to 20 wt.% of the total amount of fat.

6. An emulsion according to claim 1, wherein the quick crystallizing fat had a melting point ranging from 35 to 50"C.

7. An emulsion according to claim 1, wherein the quick crystallizing fat consists of substantially fully hydrogenated palmkernel fat.

8. An emulsion according to claim 1, wherein the quick crystallizing fat consists of hydrogenated oils having a level of fatty acids in the trans-configuration ranging from 30 to 70%.

9. An emulsion according to claim 1, wherein the dispersed, aqueous phase contains, besides the quick crystallizing fat, butterfat.

1 0. An emulsion according to claim 1, wherein the dispersed aqueous phase contains, besides the quick crystallizing fat, hydrogenated palm oil or fractions thereof.

11. An emulsion according to claim 1, wherein the dispersed, aqueous phase contains buttermilk constituents and a secondary protein.

1 2. An emulsion according to claim 11, wherein the dispersed, aqueous phase contains sodium caseinate and buttermilk constituents.

1 3. An emulsion according to claim 1, wherein the protein constitutes 0.1 to 1 5 wt.% of the emulsion.

14. An emulsion according to claim 13, wherein the protein constitutes 5 to 25 wt.% of the dispersed phase.

1 5. An emulsion according to claim 1, wherein the dispersed phase contains a monoglyceride.

1 6. An emulsion according to claim 1, wherein the dispersed phase contains a viscosityincreasing agent or a gelling agent.

1 7. An emulsion according to claim 16, wherein the dispersed phase contains xanthan gum.

18. An emulsion according to claim 1, wherein the buttermilk constituents consist of whole buttermilk powder.

1 9. An emulsion according to claim 18, wherein the buttermilk powder is present in an amount ranging from 0.1 to 5 wt.% on the total spread.

20. An emulsion according to claim 1, wherein the emulsion is of the oil-in-water-in-oil type.

21. An emulsion according to claim 1, wherein the level of fat ranges from 30 to 65 wt.%.

22. An emulsion according to claim 1, wherein the continuous fat phase contains a fat having the following fat solids profile: Neo = 15-60; N20 = 10-35; N352.

23. An emulsion according to claim 22, wherein the continuous fat phase contains butterfat.

24. An emulsion according to claim 1, wherein the continuous fat phase contains a fat blend consisting of (1) a liquid oil which is substantially free from crystallized fat at 10"C, (2) a hydrogenated fat having a melting point from 33 to 43"C, (3) an interesterified mixture obtained from palm oil and quick crystallizing fat, and (4) butterfat.

25. An emulsion according to claim 1, wherein the continuous phase contains a monoglyceride.

26. Fat-continuous emulsions as hereinbefore described, with particular reference to the Examples.

27. A process for producing a fat-continuous emulsion having a level of fat ranging from 25 to 75 wt.%, comprising: (1) producing an aqueous phase constituting the dispersed, aqueous phase of the emulsion, from buttermilk constituents, water and a quick crystallizing fat having a melting point ranging from 30 to 60"C, selected from the group consisting of hydrogenated palmkernel, coconut, babassu, ouricurum, murumuru, tucum and cocoabutter fat, cocoabutter substitutes and oils consisting of triglycerides from fatty acids in the trans-configuration; and (2) emulsifying the aqueous phase thus obtained with a fat phase comprising the remaining components of the total fat blend.

28. A process according to claim 27, wherein the aqueous phase is produced and emulsified with the fat phase at a temperature which is at least as high as the melting temperature of the fat.

29. A process according to claim 27, wherein the aqueous phase is homogenized and deaerated prior to the emulsification step.

30. A process according to claim 27, wherein (A) the dispersed, aqueous phase of the emulsion is produced by (1) preparing a cream from water, buttermilk powder and the quick crystallizing fat, and (2) preparing a proteinaceous aqueous phase substantially free from fat, starting from water, protein and other minor ingredients; (B) the final emulsion is produced by first emulsifying the proteinaceous aqueous phase produced in step (2) with the continuous fat phase to obtain a pre-mix and subsequently mixing the cream obtained in step (1) with said pre-mix.

31. A process according to claim 27, wherein (A) the dispersed, aqueous phase of the emulsion is produced from (1) a cream prepared from water, buttermilk powder and the quick crystallizing fat and (2) a proteinaceous aqueous phase substantially free from fats, prepared from water, protein and other minor ingredients, (B) the final emulsion is produced by first combining the cream and the proteinaceous aqueous phase and subsequently emulsifying the combined phases with the continuous fat phase.

32. A process according to claim 27, wherein (1) all the ingredients of the dispersed aqueous phase except the quick melting fat and the emulsifier are dissolved in water and warmed up to a temperature which is at least as high as the melting point of the quick melting fat; (2) molten quick melting fat and emulsifier are mixed with the mixture obtained in (1); (3) the mixture obtained in step (2) is emulsified with a molten fat phase containing the remaining components of the total fat blend.

33. A process for producing fat-continuous spreads having a level of fat ranging from 25 to 75 wt.%, comprising: (1) producing a fat-continuous emulsion as claimed in any one of the preceding claims 28-33, and (2) texturising the fat-continuous emulsion by cooling and working it to obtain a spread of the desired plasticity.

34. Spreads as hereinbefore described, with particular reference to the Examples.