WO2005004642A1

WO2005004642A1 - Fat-continuous low fat products

Info

Publication number: WO2005004642A1
Application number: PCT/IE2004/000095
Authority: WO
Inventors: Neil Joseph Bourke
Original assignee: Kerry Group Services Ltd
Priority date: 2003-07-10
Filing date: 2004-07-08
Publication date: 2005-01-20
Also published as: EP1646293A1

Abstract

Fat-continuous low fat products of the water-in-oil emulsion type and process thereof are provided, the emulsion comrising 3 to less than 12% fat by weight of the product. The fat phase comprises a high amount of monoglyceride and/or diglycerides of fatty acids. Fat compositions are also provided that are particularly suitable for use in the fat products and processes according to the invention.

Description

FAT-CONTINUOUS LOW FAT PRODUCTS

TECHNICAL FIELD OF THE INNENTION

The present invention relates to water-in-oil products having a particularly low fat content, to processes for their production, and to fat compositions for use therein.

BACKGROUND OF THE INVENTION

The traditional spreads, butter and margarine, consist of a water-in-oil emulsion containing very high levels of the oil, or fat phase. In recent years, due to the rising of raw materials costs and the increased awareness of the health implications of fat consumption, there has been increasing demand for spreads with reduced fat content and a number of products have reached the market which have fat contents below 50% by weight, i.e. low fat spreads predominantly of the water-in-oil type.

Low fat spreads predominantly of the water-in-oil emulsion type are now commonplace in many markets where spreading with so-called yellow fats is the norm. The term yellow fats is used to encompass a wide range of foodstuffs, which have the following in common: the emulsion type is water-in-oil comprising a fat phase and a water phase; their colour is in the yellow-orange spectrum; and the flavour is often reminiscent of natural butter.

The texture of such yellow fats can range from almost liquid to solid and the most common use of yellow fats is for spreading on baked goods. Butter, whether natural or recombined, is considered a yellow fat.

The maintenance of a stable water-in-oil emulsion, is an important characteristic for ensuring smooth and consistent production of margarine and fat spreads. Such low-fat spreads and margarine substitutes are also required to have certain flow or spreading characteristics and should resist oil or water exudation. Further, they should simulate the characteristics of butter and margarine, including rapid melt on the tongue, good moufhfeel, fairly glossy appearance, good stability to temperature cycling, and freeze/thaw stability.

The maintenance of these desirable characteristics becomes critically important when the fat content of fat-containing food products is lowered below 50% fat, and especially critical when so-called half fat spreads are being made i.e. app. 35-40% fat or even lower. When decreasing the fat content, i.e. reducing the continuous phase, the stability of the dispersion is threatened. Phase separation or phase inversion of a water-in-oil emulsion to an oil-in- water emulsion will usually lead to product rejection.

In addition, fat-continuous spreads of still lower fat content than 35% by weight of the composition are more difficult to produce, since manufacturing problems worsen with increasing water content and a still further reduced continuous fat phase.

Numerous solutions have been proposed in the art each striving for lower fat containing water-in-oil emulsions.

WO 89/07893 discloses a low fat spread, which is a water-in-oil emulsion of fats, water and a disaccharide ester emulsifϊer, having less than 35 % by weight of fat. It is produced by blending a portion of aqueous phase with the fat phase and subsequently blending further portions of aqueous phase to reduce the overall fat content to the desired final value

EP 0,420,314 discloses spreads comprising less than 30 wt.% of a continuous fat phase and at least 70 wt.% of an aqueous phase, wherein the spread comprises 0.1 to 1.5 wt.% of a mixture of monoglycerides and polyglycerol esters in a weight ratio of monoglycerides to polyglycerol esters in the range of 1 : 10 to 10: 1.

EP 0,590,203 discloses ultra low fat spread. The spread is a fat-continuous dispersion having a fat content of 5-13.9 wt.% The dispersed aqueous phase is characterised by the absence of any gelling or thickening agent. The emulsifiers used therein are triglycerol esters or combinations of a triglycerol ester and a co-emulsifier, e.g. a monoacyl glycerol mixture. The spread can be prepared by slowly adding water phase to a stirred fat-continuous dispersion with a reduced fat content.

WO 90/09107 discloses a water-in-oil emulsion containing 12 to 30% fatty phase and 0.35 to 4% of monoglycerides by weight of the emulsion.

Still, despite the advances in the art, it has been found that the properties of such product, in particular in terms of their shelf-stability and the organoleptic properties of the product such as sensory, olfactory and visual perception could be improved.

Accordingly, there is a need for a low fat spread, in particular with a content of fat lower than or equal to 10%, that has improved shelf-life but also exhibits improved sensory, olfactory and visual properties.

Typically, two emulsion techniques are known for the production of fat spreads, namely the fat-continuous method, and the phase inversion method. These techniques are coupled with one of the two conventional production methods namely pre-mix system or proportional in line mixing system.

The former is carried out in a batch tank, or pre-mix tank where all the ingredients major and minor are brought into one tank and the desired emulsion in formed. This emulsion is then processed in conventional margarine type equipment e.g.. Notators or scraped surface heat exchangers.

However, as described hereinbefore, fat-continuous spreads of very low fat content are difficult to produce, since manufacturing problems increase with increasing water content and reduced continuous fat phase. This problem is particularly acute with spreads containing not more than 10 wt.% fat (so-called ultra low fat spreads).

Further, a problem arises where high dosages of unsaturated monoglycerides are used in some low fat spread recipes, resulting in instability especially in the processing of the emulsion. The emulsion tends towards inversion, i.e. it assumes an oil-in-water emulsion form. Without wishing to be bound by theory, it is believed that this phenomena is due to the tendency of high concentrations of monoglycerides to form aqueous mesophases at elevated temperatures. Therefore, concentration of 1.25% by weight of the fat phase are usually quoted as being optimal for low fat spreads (40% fat) using conventional processing. However, such an amount has been found insufficient to emulsify all the water phase in ultra low fat spreads.

Accordingly, a process has been described making use of low amount of monoglyceride as disclosed for example in EP 0,420,314, hereinbefore mentioned.

A further problem is encountered when the fat-continuous method is coupled with the pre-mix system, thereby raising the production time i.e. the emulsion make-up time. Indeed, the lower the fat content, the higher the amount of the water phase, which in turn increases the emulsion make up time i.e. the time taken to carefully add the water phase at a pre-determined rate so as to ensure maintenance of fat continuity. As a result long batch make up times are obtained, which in turn can starve the continuous scraped surface heat exchanger line of product and result in a "stop start" type of production scheme, thus raising the cost of production.

Accordingly, there is also a need for a process of making low fat spread that is economical and that also provides low fat products with improved shelf stability and organoleptic properties.

It has now been found, despite the known prejudice against the use of high levels of emulsifiers, and particularly of high levels of monoglycerides, that the use of considerable amount of monoglycerides of fatty acids and/or diglycerides of fatty acid in the continuous fat phase makes it possible to fulfil such need. Further, it has also been found that bringing the water phase in direct contact with the fat phase, wherein the water phase has a temperature below 10°C results in a process with reduced or no phase inversion problems as well as with improved ability to raise the water phase levels to ultra high levels. As a result, an economical product and process are provided. SUMMARY OF THE INNENTION

In one aspect of the present invention, there are provided fat-continuous low fat products in the water-in-oil form, and comprising: a) -a water phase; b) -a fat phase comprising an amount of fat between 3 to less than 12% by weight of the product, characterised in that the fat phase comprises 20 to 98% by weight of the fat phase of fat and 2 to 80% by weight of the fat phase of emulsifiers selected from monoglyceride of fatty acids, diglycerides of fatty acids and mixtures thereof.

In another aspect of the present invention, there is provided a process for making the invention product which comprises the step of contacting the water phase with the fat- phase, wherein the water-phase has been tempered to a temperature of or below 10°C prior to contacting with the fat phase.

In a third aspect of the present invention, there is provided a composition for use in the manufacture of the invention products, comprising at least 60 wt.% of a combination of fat, emulsifϊer and co-emulsifier, said emulsifier being selected from the group consisting of monoglyceride of fatty acids, diglyceride of fatty acids and combinations thereof; and said co-emulsifier being selected from the group consisting of polyglycerol esters of fatty acids, sorbitan esters of fatty acids, polyglycerol ester of polycondensed ricinoleic acid, digalactosyldiglyceride, lecithin and combinations thereof wherein: 0.02 < ([emulsifιer]+[co-emulsifιer])/[fat] < 1.0; and 0.03 < [co-emulsifier]/[emulsifier] < 1.0.

DETAILED DESCRIPTION OF THE INNENTION

A. Composition

It is an essential feature of the fat-continuous low fat products of the invention that they are in the form of a water-in-oil emulsion. Determination of the presence of a water-in oil emulsion can suitably be done by visual observation techniques such as by light microscope, con focal microscopy, or other suitable microscopic techniques; dye colouration; electrical conductivity measurements; focused laser beams, as conventionally known to those skilled in the art.

For the purpose of the present invention, by "water-in-oil emulsion", it is meant that the dispersed phase, water phase in this instance, is a phase consisting of discrete parts fully surrounded by material of the other phase i.e. the fat phase.

The emulsion according to the present invention comprises a water-phase and a fat phase. In this specification, unless otherwise indicated, the term 'fat' refers to edible fatty substances in a general sense, including natural and/or synthesised fats like triglycerides and sucrose polyesters of fatty acid (SPE). The terms "oil" and "fat" are used interchangeably and are to be regarded as synonyms unless indicated otherwise.

1. Fat Phase

The fat phase comprises from 3 to less than 12%, preferably from 3 to 11% and more preferably from 3 to 10%, and even more preferably from 3 to less than 10% fat by weight of the product. One further more preferred range for the fat in the fat phase is of from 3 to 8 wt.%. Essential ingredients of the fat phase are one or more fats and one or more emulsifiers.

Typical fats for use herein are selected from animal, vegetable, marine, milk oils or mixtures thereof. These may be directly obtained from a natural source by pressing and/or extraction and may also have been subjected to physical and/or chemical treatment such as refining, fractionation, hydrogenation, and interesterification.

Preferred fats are selected from soybean oil, sunflower oil, palm oil, coconut oil, fish oil, lard and tallow, which may have been partially or completely hydrogenated or modified otherwise, as well as non-toxic fatty materials having properties similar to triglycerides, which materials may be indigestible, such as for example waxes, e.g. jojoba oil and hydrogenated jojoba oil or even sucrose polyesters of fatty acid (SPE). The fats are present at levels in the fat phase of from 20 to 98% by weight of the fat phase, preferably of from 20% to 97.5%, more preferably of from 20% to 97%.

The fat phase also comprises an emulsifier. Emulsifiers for use in the present invention are selected from monoglycerides of fatty acid, diglycerides of fatty acid, and mixtures thereof, preferably is a mixture of mono- and diglycerides of fatty acid. In another preferred embodiment the emulsifier is a monoglyceride.

Mono- and di-glycerides of fatty acids (also referred to as monoglycerides and diglycerides) are preferably derived from C12-C22 fatty acids and are obtainable from triglycerides of these fatty acids which can be of both vegetable and animal origin, e.g. from soya bean oil, coconut oil, babussa oil, palm oil, sunflower oil, lard, tallow and fish oil, optionally hydrogenated or fractionated. Mixtures of mainly C₁₆-C₁₈ fatty acid are preferred. The mono-diglycerides can be prepared by interesterification with glycerol, usually in the presence of an alkaline catalyst. Mostly the triglyceride oil and the glycerol reacted are free from water or moisture. Further details of this reaction are e.g. disclosed in US-A-2 875 221 (Birnbaum). Esterification leads to mixtures of mono- and diglycerides. After removal of water and unreacted glycerol the product obtained contains up to 65 wt % of monoglycerides. More pure monoglycerides can be obtained by molecular distilling the monoglycerides from the mixture and results in monoglycerides containing at least 90% monoglycerides. Such distilled products are e.g. marketed under the tradename Myverol ex Quest, Naarden, Netherlands. Crystallisation and other fractionation processes may also yield similar relatively pure products. The term "distilled monoglycerides" as used here has a broader meaning than the literal sense and covers also purified monoglycerides obtained by other means than distillation. Monoglycerides containing 60 to 80% monoglycerides are usually prepared by diluting distilled monoglycerides with undistilled mono-diglycerides. They are marketed as such and sometimes in admixture with triglyceride fat as co-emulsifier. Emulsifiers containing from 30% up to 98% monoglycerides are suitable for use in the current invention. Preferred emulsifiers are those containing at least 40%, preferably of at least 55%, more preferably at least 80% and most preferably at least 90% by weight of monoglycerides by weight of the emulsifier . The preferred type of emulsifiers in low fat spread production using the fat-continuous method are the unsaturated or partly unsaturated monoglycerides. Unsaturated monoglycerides are characterized in that they in general have iodine values higher that 20. This unsaturation lends them to be useful in forming and stabilizing the low fat spreads, and in controlling the rate of crystallization of the fat phase. More preferably, the mono or mono-and diglyceride of fatty acid is characterised in that about 90% of the fatty acids are C16 or longer and in that the emulsifier has an iodine value of 20- 115, preferably 25-115, and most preferably 30-115.

Examples of these include the Admul MG range such as Admul MG 40-35K; and Admul MG 60-35K commercially available from Quest International, in The Netherlands, with a respective content of 45% and 60% by weight of monoglycerides. A preferred example is the Myverol range of products commercially available from Quest International, in The Netherlands.

The amount of the above mentioned emulsifiers, either used singly or in combination is preferably 2-80% and most preferably 2.5-80%, and optimally 3-80%, calculated on the total weight of the fat composition.

Commercially available products under the tradename Myvatex (ex Quest International) can advantageously be used in accordance with the present invention as these comprise both the oil, and required emulsifier. In particular, Myvatex ULF 100 is a very suitable composition, containing a blend of oil and hydrogenated fats, emulsifiers with a minimum content of mono- and/or di-glycerides of fatty acids of at least 10 wt.% and a maximum content of polyglycerol polyricinoleate of 4 wt.%.

Additionally, the fat phase can also comprise additional fat-soluble ingredients provided these are of a fatty nature. Typical examples of these are selected from polyglycerol esters of fatty acids, sorbitan esters of fatty acids such as Span 80, polyglycerol ester of polycondensed riciiioleic acid such as ADMUL WOL™ from Quest International, digalactosyldiglyceride, lecithin, and mixtures thereof. In one preferred embodiment, the co-emulsifier is selected from the group of polyglycerol esters of fatty acids, sorbitan esters of fatty acids, polyglycerol ester of polycondensed ricinoleic acid, lecithin, and mixtures thereof. In another preferred embodiment, the co- emulsifier is selected from polyglycerol polyricinoleate, digalactosyl diglyceride and mixtures thereof. Co-emulsifiers, when present are preferably contained in the product in a weight proportion lower to that of the emulsifier. Typically the weight ratio of [co- emulsifier]/[emulsifier] is at least 0.03, in a preferred embodiment at least 0.1. Said ratio can be as high as 10, however a maximal ratio of [co-emulsifier]/[emulsifier] of 1.0 is preferred.

Furthermore, the fat phase can also comprise additional ingredients that are commonly used in spreadable fat products. These are typically selected from the group of coloring agents, flavors, vitamins, anti-oxidants, preservatives, calcified seaweed , and the like. When present, these additional ingredients will be present in an amount of at least 10 mg/kg of the fat phase. More preferably, said additional ingredients will be present in an amount of from 0.1% to 15%, preferably of from 0.2% to 13% by weight of the fat phase. In particular, co-emulsifiers, when present are typically present up to 4% by weight of the fat phase.

2. Water phase

The water phase forms the balance of the product. Its composition is not particularly critical to the present invention. Whilst an aqueous phase consisting of pure water may be incorporated in the product it is presently preferred that the aqueous phase contains one or more dissolved or dispersed additional ingredients selected from protein, stabiliser, salt, a calcium salt, flavour (generally in the range of 100 to 2000 ppm) and preservatives (for instance at about 1,000 ppm), and other conventional accessory ingredients commonly used in spreads like pH regulating agents, metal chelators such as EDTA or sodium citrate, buffering agents, bulking agents, colours, anti-oxidants, vitamins, phytosterols, fibres, OSA starches, humectants, sugars, polyols, artificial sweeteners, live probiotic bacteria, prebiotic, and mixtures thereof.

Suitable proteins for use herein are selected from dairy proteins (for instance caseins, casemates and liquid, concentrated or dried buttermilk and skimmed milk) and other protein materials, (for instance gelatin, fish protein and vegetable, especially soya protein) to contribute to the flavour and/or to bind water in the aqueous phase. Accordingly, the aqueous phase may contain a stabiliser such as a gelling agent, particularly a high molecular weight hydrocolloid such as edible gums (for instance guar gum, xanthan and carrageenan), starches (for instance hydrolysed starches, such as maltodextrins, modified starches and starch derivatives), gelatin, alginates, celluloses and/or cellulose derivatives.

Alternatively or additionally, the water phase may comprise fat as defined hereinbefore so that the water phase is in the oil in water form and the resulting product is in the oil- in- water-in-oil (o/w/o) form. In this instance, the total amount of fat can range from 3 to 70% by weight of the fat product.

The present invention enables the manufacture of fat-continuous ultra-low fat products in the form of mayonnaise, dressings, spreads, fillings, toppings or even in desserts. In a particularly preferred embodiment, the present product is a spread, a filling, or a topping. Most preferably, the present fat-continuous low fat product is a spread.

It is preferred that the products according to the invention have a butter-like texture which as known to the man skilled in the art can be associated with a particular melting profile of the fat phase and a desirable distribution of the droplets of the aqueous phase.

B. Process

It was found that fat-continuous products in water-in-oil emulsion form, such as those according to the present invention, can suitably be manufactured by the following general procedure:

The fat phase is formed by melting the major fat phase components together with the fat-soluble ingredients while stirring and heating to such a temperature that all the components are dissolved and or molten. Typically, this fat phase is collected in a tank and tempered to a temperature of between 35°C and 55°C. The water phase is formed by dissolving all the water-soluble ingredients into water while stirring. Once obtained, the water phase containing optional dissolved ingredients is preferably subjected to a pasteurisation or sterilisation step prior to tempering the water phase to a temperature of less than or equal to the melting point of the fat phase. Preferably the water phase is tempered to a temperature of at least 3 °C below, more preferably of at least 5 °C below, and most preferably of at least 10 °C below the melting point of the fat phase. In a particular embodiment the water phase is tempered to a temperature of less than or equal to 10°C, more preferably of 8°C or lower, even more preferably of below 5°C. The water phase can also be in a preferred mode of execution in the frozen state, i.e. at a temperature lower than 0°C and this is then added to the fat phase as small pieces of crushed frozen water, i.e. with an average particle size small enough to prevent physical obstructions within the mixing equipment, i.e. typically within the range of 0.1-10 mm, preferably within the range of 3-10 mm. Advantageously, in such a manner, a control of the release of water to the fat/emulsion is obtained.

The emulsion formation process according to the invention is largely a batch process, whereby the pre-chilled and/or frozen water phase is slowly added directly to the fat phase and stirred continuously until the desired emulsion is formed. The current invention advantageously enables crystallisation and emulsification of the fat phase using an exclusively batch system. A further advantage of the current invention is the ease with which the very low fat emulsions can be formed with a low risk of phase inversion; which as described hereinbefore is a chronic problem in the manufacture of low fat products such as low fat spreads. The method of manufacture further allows the use of relatively simple equipment, eliminating the need for expensive scraped surface heat exchangers.

The water-in-oil emulsion is formed by bringing the aforementioned two phases in contact with each other, e.g. in a batch system, i.e. the water and the fat phase are added together in a tank to form a pre-mix.

Alternatively, the water phase which has been brought to a temperature of approximately 10°C or lower can be first added to the mixing tank, while the fat phase is then added in the molten state (approximately 50°C) to the cold water phase. The temperature is thereafter gradually increased whilst the mix is maintained stirred at all times at approximately 200 RPM and at a temperature of between 21 °C and 35 °C, preferably of between 26°C and 30°C; at which point the consistence changes from lumps of fat in water, to a thick, salve like mix which had taken on the water-in-oil emulsion conformation. This process method has the advantage that it reduces the emulsion make-up time considerably, changing it from a matter of hours to approximately 30 minutes. Another advantage of this alternative is that the phase inversion occurs under relatively low shear conditions, thus reducing the investment and maintenance costs on the equipment which is standard for these phase inversion operations.

The whole operation of cooling / crystallisation and emulsification is preferably carried out in a batch wise manner, in a single tank. When the desired emulsion quality, and degree of crystallisation, has been reached as is well understood by those skilled in the art, the emulsion can be pumped out of the tank through an appropriate filling line, into the final packaging. The desired emulsion quality can be assessed by determining the water droplet size and distribution, using visual observation techniques e.g. light microscopy, confocal microscopy, or other suitable microscopic techniques, time domain NMR methods, focused laser beams, etc. The desired crystallinity can suitably be determined by known methods, e.g. polarised light microscopy, time domain nuclear magnetic resonance, rheological tests, or simple observation and judgment learned by experience by those skilled in the art.

The operation as described above is not labour intensive, and the timing of batch makeup to processing to eventual filling is not critical as in the case of traditional fat spreads processing, giving the manufacturer a greater degree of flexibility and robustness in the overall process.

Accordingly, there is provided a process for making fat-continuous emulsions comprising a fat phase and a water phase, wherein the emulsion can comprise from 3- 70 wt.% of fat, based on the total weight of the emulsion, which process comprises the step of contacting the water-phase with the fat-phase, wherein the water-phase has been tempered to a temperature of or below the melting point of the fat phase, preferably of at least 3 °C below, more preferably of at least 5 °C below, and most preferably of at least 10 °C below the melting point of the fat phase, prior to being brought in contact with the fat phase. In a particular embodiment the water phase has been tempered to a temperature of or below 10°C prior to being brought in contact with the fat phase. In a particularly preferred embodiment, the process is used for preparing low-fat water-in- oil emulsions, comprising less than 35 wt.% of fat, especially less than 20 wt.% of fat, based on the total weight of the emulsion. In a most preferred embodiment the emulsion produced is a composition according to the present invention, comprising 3 to less than 12 wt.% of fat, based on the total weight of the emulsion.

Alternatively, there is provided a process for making a water-in oil emulsion comprising a fat phase and a water phase, preferably the emulsion is a composition according to the present invention, which comprises the step of contacting the fat phase with the water-phase, wherein the water-phase has been tempered to a temperature of or below 10°C prior to being brought in contact with the fat phase. Preferably, the obtained mixture is stirred under gradual temperature increase up to 26-30°C until phase inversion occurs.

C. Fat composition

The present invention also provides a fat composition that may suitably be employed in the manufacture of the fat-continuous low fat products according to the present invention. In particular, this aspect of the invention relates to a fat composition that contains most of the components that end up in the fat phase of the present product. Said fat composition may be combined with the aqueous phase components of the same product, and optionally fat phase components such as liquid oil, so as to be converted into a fat-continuous low fat product by simple processing, e.g. without the need of using one or more scraped surface heat exchangers.

Accordingly, one aspect of the present invention relates to fat compositions, preferably comprising essential components that make up the fat phase of the desired water-in-oil product, such that the fat-continuous low fat product can be obtained by simply combining it with an appropriate amount of an aqueous solution, according to the process as described herein above. Suitable fat compositions typically comprise at least 60 wt.% of a combination of fats, emulsifiers and co-emulsifiers; said emulsifier being selected from the group consisting of monoglycerides of fatty acids, diglycerides of fatty acids and combinations thereof; and said co-emulsifier being selected from the group consisting of polyglycerol esters of fatty acids, sorbitan esters of fatty acids, polyglycerol ester of polycondensed ricinoleic acid, digalactosyldiglyceride, lecithin and combinations thereof, wherein 0.02 < ([emulsifier]+[co-emulsifier]) / [fat] < 1.0; and 0.03 < [co-emulsifier]/[emulsifier] < 1.0

Low-fat water-in-oil products according to the present invention, such as spreads, have to meet specific requirements with regard to spreadability and organoleptic properties such as mouth-feel. To achieve this, the fat in the fat composition according to the present invention may comprise a structuring amount of a hardstock fat. It is preferred that compositions are provided, wherein the fat has a solid fat content that is characterized by N ₀ > 5, more preferably N₂₀ > 10, most preferably N ₀ 15. Preferably, the fat contained in the fat composition exhibits a N₃ of less than 40, more preferably of less than 35. If the present fat composition is to be blended with a liquid oil as well as the aqueous phase components, the N₃₅ of the composition may be relatively high as the blending with the oil component will reduce the N₃₅ of the fat phase to an organoleptically acceptable level. If no oil is added, it is preferred that the present fat composition has a N₃ of less than 10, most preferably of less than 5. The N- value may suitably be determined using the methodology described in Fette, Seifen, Anstrichmittel 80 180-160 (1978).

As mentioned the emulsifier employed in the present fat composition is selected from the group of mono-glycerides of fatty acids and di-glycerides of fatty acids and combinations thereof. Preferably the emulsifier comprises at least 40 %, preferably at least 55 %, more preferably at least 80 % and most preferably at least 90 % of monoglycerides by weight of the emulsifier. In a particularly preferred embodiment of the invention, the co-emulsifier is selected from the group consisting of polyglycerol polyricinoleate (PGPR), digalactosyl diglyceride (DGDG) and combinations thereof. Most preferably, the co-emulsifier is PGPR.

Additional ingredients that may be incorporated advantageously in the present fat composition, include coloring agents, flavors, vitamins, anti-oxidants, calcified seaweed, and the like, in amounts of at least 10 mg/kg, preferably at least 50 mg/kg.

A very much preferred embodiment of the present invention, provides fat compositions, wherein the combination of fat, emulsifier and co-emulsifier comprises 0.5 - 8.0 wt.% co-emulsifier and 5.0 - 40 wt.% emulsifier.

D. Applications

Another aspect of the invention relates to the use of a fat composition as defined above in the manufacture of a fat-continuous low fat product in water-in-oil form; said product comprising between 3 and less than 12 wt.% of fat.

The invention also concerns a method of manufacturing a fat-continuous low fat product in the water-in-oil form, comprising 3 to less than 12 wt.% of fat, which method comprises the step of combining the fat composition with an aqueous solution. In a preferred embodiment, the aqueous solution has been tempered to a temperature of or below 10°C prior to contacting with the fat phase. The present method preferably employs one or more mixing devices so as to facilitate the dispersal of the aqueous solution throughout the fat composition.

The present method may optionally include the step of combining the present fat composition with another fat component, especially a liquid oil. hi the event such another fat component is employed, it is preferred to first combine said fat component with the present fat composition before adding the aqueous solution. A major advantage of the use of the present fat composition resides in the fact that it is feasible to produce good quality fat-continuous low fat products therefrom without the need of employing scraped surface heat exchangers. Thus, the present invention enables the manufacture of such products without the need of large capital investments and with much lower running costs.

The following are non-limiting examples illustrating the invention

EXAMPLES

Example 1

Fat phase: wt.%

*Fat Blend 10.0

Natural carotene 0.003

Flavours 0.02

Water phase wt.% Water 89.577

Salt 0.3

Citric acid (10%) 0.05

Potassium sorbate 0.05

*Fat Blend: 8.4 wt.% oils and fats and 1.2 wt.% of monoglycerides of fatty acid, and 0.4 wt.% of polyglycerol polyricinoleate,

Process:

The fat-soluble ingredients were all heated together to dissolve the crystalline elements and the whole mixture was tempered to 45°C. The water phase ingredients were dissolved in the water, and subjected to a pasteurisation step. The whole water phase was then frozen (temperature below 0°C). When frozen, the block was crashed to form ice particles with an average particle size small enough to prevent physical obstructions with the mixing equipment and typically are between 3-10 mm. The ice particles were slowly added to the fat phase whilst the fat phase was stirred continuously, in a cylindrical tank, with a scraper type mixing device which was mounted from the bottom of the tank, and which was able to maintain the whole contents of the tank in motion. The RPM of the mixer varied from 5-200 RPM. The addition of the crushed ice particles was carried out over a period of approximately 2 hours, and the emulsion was maintained stirred for a further 2 hours. The fat phase crystallised quickly when initial contact was made with the ice, and the fat phase stayed in a crystallised state throughout the whole process of ice crystal addition. The water phase i.e. the crushed ice was partly melted when added to the emulsion but this so-called "free water" was also easily incorporated into the fatty matrix of the fat blend. Thus the water phase can be in the form of deeply chilled water without having any crystalline (ice crystalline) particles, or a mixture of crystalline and liquid parts. The whole of the water phase was eventually added to the fat phase with the result that the final emulsion was predominantly fat-continuous indicated by the low conductivity reading taken, (0.1 microsiemens/cm ) and the ease of uptake of a fat soluble red dye, Sudan Red, and the inability of the emulsion to mix with water. The emulsion had typical spreadable characteristics of a fat spread with much higher fat contents e.g. 40% fat, and the emulsion melted and dispersed well in the mouth so that the flavour components could be perceived together with the salt in the encapsulated water phase.

Average droplet size of the emulsion measured using a light microscope was between 3 and 6 microns.

Example 2

Fat phase: wt%

*Fat Blend 11.35 Water phase t %

Sherex CS 9644 ** 16

Sugar 8.5

Fructose 3.5

Potassium sorbate 0.1

Citric acid 0.3

Carmine colour 0.03

Strawberry flavour 0.1

Water up to 100

*Fat Blend: 10 wt.% oils and hydrogenated fats and 1.0 wt.% of monoglycerides of fatty acid, and 0.35 wt.% of polyglycerol polyricinoleate ** Sherex CS 9644 is a cultured dairy product comprising culture grade "A" dairy solids (Grade "A" non fat milk, sugar, and lactic acid culture), fructose, citric acid and sodium chloride and providing about 10 wt.% of protein, i.e. in the exemplified composition providing about 1.0 wt.% protein.

The making of the composition was carried out using the same process as above mentioned in Example 1. Average droplet size of the emulsion measured using a light microscope was between 3 and 6 microns.

The composition obtained was a very stable water-in oil emulsion which did not release water when spread at 5°C and which easily retained its shape and spread integrity at 20°C.

Example 3

Fat phase: wt.%

*Fat Blend 10.0 Water phase wt.%

Water 89.577

Salt 0.3

Citric acid (10%) 0.05

Potassium sorbate 0.05

Na EDTA up to 100%

Alternatively, the water phase which was made by dissolving in the water the water phase and subjected to a pasteurisation step, was first added to the mixing tank, the water phase having a temperature of approximately 10°C of lower. The fat phase i.e. 10% of the fat blend was then added in the molten state (approximately 50°C) to the cold water phase. The temperature was gradually increased whilst the mix was maintained stirred at all times at approximately 200 RPM and at a temperature of between 26°C and 30°C, at which point the consistence changed from lumps of fat in water, to a thick, salve like mix which had taken on the water-in-oil emulsion conformation. This process method has the advantage that it reduces the emulsion make-up time considerably, changing it from a matters of hours to approximately 30 minutes. This matter of phase inversion occurs under relatively low shear conditions, thus reducing the investment and maintenance costs on the equipment which is standard for these phase inversion operations.

Example 4-Distribution of droplet sizes

The distribution of the droplets size of the exemplified compositions 1-3 was analysed using the D(_3>2) method. The present specification of averaged particle size diameters is according to definitions found in Alderliesten, M., Mean Particle Diameters, Part. Part. Syst. Charact. 8 (1991) 237-241.

TABLE I shows the accumulated volume percentage for subsequent size range

Table I-distribution of droplet sizes ([mu]m) up to Volume %

Claims

1. Fat-continuous low fat product in the water-in-oil form, and comprising: a) -a water phase; b) -a fat phase comprising an amount of fat between 3 to less than 12% by weight of the product, characterised in that the fat phase comprises 20 to 98% by weight of the fat phase of oil, preferably triglycerides and/or sucrose polyesters of fatty acids, and 2 to 80% by weight of the fat phase of emulsifiers selected from monoglyceride of fatty acids, diglycerides of fatty acids and mixture thereof.

2. Product according to claim 1, wherein the amount of fat is of from 3 to 10% by weight of the product, preferably of from 3 to 8% by weight of the product.

3. Product according to either one of claim 1 or 2, wherein the emulsifier comprises at least 40%, preferably at least 55%, more preferably at least 80% and most preferably at least 90% of monoglycerides by weight of the emulsifier.

4. Product according to any one of Claim 1-3, wherein the composition further comprises co-emulsifiers, preferably selected from polyglycerol esters of fatty acids, sorbitan esters of fatty acids, polyglycerol ester of polycondensed ricinoleic acid, digalactosyldiglyceride, lecithin, and mixtures thereof.

5. Product according to any one of claims 1-4 in the form of a spread, a mayonnaise, a dressing, a filling, a topping or a dessert.

6. A process for making a fat-continuous emulsion comprising a fat phase and a water phase, the emulsion comprising from 3 to 70% by weight of fat, based on the total weight of the emulsion, which process comprises the step of contacting the fat phase with the water-phase, wherein the water-phase has been tempered to a temperature of or below 10 °C prior to contacting with the fat phase.

7. A process for making a fat-continuous emulsion comprising a fat phase and a water phase, the emulsion comprising from 3 to 70% by weight of fat, based on the total weight of the emulsion, which process comprises the step of contacting the water- phase with the fat-phase, wherein the water-phase has been tempered to a temperature of or below the melting point of the fat phase, preferably of at least 3 °C below, more preferably of at least 5 °C below, and most preferably of at least 10 °C below the melting point of the fat phase, prior to being brought in contact with the fat phase.

8. A process according to claim 6 or 7, wherein the contacted phases are mixed under increased temperatures of up to 21-35°C, preferably 26-30°C, until phase inversion is obtained.

9. A process according to any one of claims 6-8, wherein the emulsion comprises less than 35 wt.% of fat, preferably less than 20 wt.% of fat, based on the total weight of the emulsion.

10. A process according to any one of claims 6-8, wherein the emulsion is as defined in any one of claims 1-5.

11. Fat composition comprising at least 60 wt.% of a combination of fat, emulsifier and co-emulsifier; said emulsifier being selected from the group consisting of monoglycerides of fatty acids, diglycerides of fatty acids and combinations thereof; and said co-emulsifier being selected from the group consisting of polyglycerol esters of fatty acids, sorbitan esters of fatty acids, polyglycerol ester of polycondensed ricinoleic acid, digalactosyldiglyceride, lecithin and combinations thereof, wherein: 0.02 < ([emulsifier]+[co-emulsifier]) / [fat] < 1.0; and 0.03 < [co-emulsifier]/[emulsifier] < 1.0.

12. Fat composition, according to claim 11, wherein the fat has a solid fat content N₃₅ <40.

13. Fat composition, according to claim 11 or 12, wherein the fat has a solid fat content N ₀ 10.

14. Fat composition according to any one of claims 11-13, wherein the emulsifier comprises at least 40%, preferably at least 55%, more preferably at least 80% and most preferably at least 90% of monoglycerides of fatty acids by weight of the emulsifier.

15. Fat composition according to any one of claims 11-14, wherein the co- emulsifier is polyglycerol polyricinoleate.

16. Fat composition according to any one of claims 11-15, wherein said combination of fat, emulsifier and co-emulsifier comprises 0.5 to 8.0 wt.% co- emulsifier and 5.0 to 40 wt.% emulsifier.

17. Fat composition according to any one of claims 11-16 further comprising additional fat-soluble ingredients of a fatty nature selected from the group of coloring agents, flavors, vitamins, calcified seaweed, anti-oxidants, and mixtures thereof, in an amount of at least 10 mg/kg.

18. Use of a fat composition according to any one of claims 11-17 in the manufacture of a fat-continuous low fat product in water-in-oil form; said product comprising between 3 and less than 12 wt.% of fat.

19. Method of manufacturing a fat-continuous low fat product in the water-in-oil form, comprising 3 to less than 12 wt.% of fat, which method comprises the step of combining a fat composition according to any one of claims 11-17 with an aqueous solution.

20. Method according to claim 19, wherein the aqueous solution has been tempered to a temperature of at least 10 °C below the melting point of the fat phase, preferably to a temperature of or below 10°C prior to contacting with the fat phase.

21. Method according to claim 19 or 20, wherein said method does not employ scraped surface heat exchangers.