Low fat edible emulsions

Abstract: An edible emulsion is disclosed having a fat content of less than 5 weight %. An edible fat or oil component is dispersed in an aqueous phase with a two-component emulsifier system comprising a primary emulsifier which acts to stabilise the emulsion and a secondary emulsifier which works in synergy with the fat or oil component to impart a desirable texture and structure to the finished product.

Description: This invention relates to an edible emulsion having a much lower fat content than conventional emulsions, and to a method of making it. Such emulsions may for example be used for spreads to be used as alternatives for butter or margarine. Other possible uses include salad dressings to be used instead of mayonnaise or salad cream, and low fat desserts. Conventional edible emulsions typically comprise a fat or oil phase dispersed in an aqueous phase, although other emulsions are known in which the fat or oil comprises the continuous phase and has the aqueous phase dispersed in it. The typical fat contents in conventional water-continuous emulsions ranges from about 80% down to 40%, and although it is in some cases regarded as desirable to reduce the fat content, it has been found difficult to produce a satisfactory emulsion having a fat content much below 20-25% since the fat or oil phase is necessary to impart the required flavour and texture. Conventional edible emulsions of the type to which the invention relates generally include a small quantity of an emulsifier and well as protein or other dairy components, gelling agents, stabilizers, flavouring, colouring etc. Some typical compositions are disclosed in EP-A-463688, which discloses plastic edible emulsions in which the oil or fat component is dispersed in a continuous aqueous phase. Although the claimed range is 5 to 21 wt.%, the exemplified compositions contain 19.6 wt.% of palm mid-fraction as the fat component. JP-A-58121766 discloses the preparation of a vegetable whipped cream composition by mixing 5-10 wt. parts of a foamable, partially hydrolysed vegetable protein with 10 - 50 parts of sugar, 4 - 40 parts of water, 0.5 - 30 parts of oil and fat and 1 -2 parts of milk casein. Lecithin or sorbitan fatty acid ester can be used as an emulsifier. EP-A-441494 discloses a low calorie fat substitute in the form of a two-phase emulsion containing 1 - 70% carbohydrate, 0.05 to 12% protein, for example egg white, soy protein isolates or milk protein isolates and 1 to 50% of an edible fat or oil and at least some of the protein being in the dispensed phase in the form of a protein-fat or protein-oil aggregates and non-aggregated protein being dissolved or suspended in the aqueous phase. The inventors have now developed a low fat edible emulsion wherein 5 wt.% or less of fat or oil component is dispersed in water, together with a sufficient quantity of an emulsifier to impart the texture and flavour required of such an emulsion. It has been found that the emulsifier can work in synergy with the fat or oil component to impart a desirable texture and structure to the finished product with good spreading properties so that it resembles a product with a much higher fat content. The present invention provides an edible emulsion comprising an aqueous dispersion of an edible fat or oil component and an emulsifier system, characterised in that the fat or oil component is present in an amount of 2 to 5 wt.%, based on the total emulsion, and in that the emulsifier system is a two-component or multi-component system which comprises a primary emulsifier comprising one or more components selected from proteins, skim milk powder, polysorbates, Datem, Citrem, sucrose esters, octenyl succinic acid (OSA) starches and gum arabic, acting to stabilise the emulsion, and a secondary emulsifier acting to de-stabilise the oil-in-water emulsion to create a substantially semi-solid plastic matrix, said secondary emulsifier including one or more mono- or diglycerides or polyglycerol esters, prepared from unsaturated or partially unsaturated fats. The aqueous phase of the composition may for example contain minor quantities of milk or other dairy components, bulking agents, gelling agents, starches and stabilizers. The oil phase comprises oils or fats which are edible and of the type generally used in the food industry. Minor ingredients such as salt, phosphates, citrates, Minor ingredients such as salt, phosphates, citrates, colouring, flavouring, vitamins, preservatives and food acids are also desirable components of the edible emulsions of the invention. The secondary emulsifier is capable of creating the desired texture and structure. Polysorbates, organic acid esters of mono- and diglycerides, propylene glycol esters, stearyl lactylates, lecithin and sucrose fatty acid esters may also be included to enhance this effect. The secondary emulsifier can be added as part of the fat or oil phase and by careful selection of the emulsifier type and grade, it can also be included as part of the aqueous phase. While the applicant does not wish to be bound by any particular theory, the secondary emulsifier is believed to function by partly destabilising the oil in water emulsion to create a substantially semi-solid plastic matrix. The emulsion preferably contains from 0.2 to 2 wt.% of this secondary emulsifier. Fats and oils can be selected from any suitable vegetable, animal or dairy source and include oils, hydrogenated and unhydrogenated fat as well as fractionated fats. The oil in water emulsion is made by emulsifying the fat phase such that a dispersion of small uniform oil droplets is formed. This emulsification process can be enhanced by the use of a high pressure homogeniser, colloid mill, Silverson mixer or similar equipment together with the presence of the primary emulsifier. This agent has a function which is different from that of the aforementioned secondary emulsifier in that its primary role is to create a stable oil in water emulsion and is selected from proteins, especially caseinate and whey protein, skim milk powder and other materials which act as oil in water emulsifiers and include, but are not limited to, polysorbates, Datem, Citrem, sucrose esters, OSA starches and gum arabic. Certain emulsifiers, which include polysorbates, are multifunctional and provide the necessary oil in water emulsification. However, paradoxically they can also act to create a de-stabilisation of this emulsion. The total content of such emulsifying agents is preferably from 0.1 to 10 wt.%. Homogenization preferably takes place at a pressure of 2 to 50 MPa (20 to 500 bar), more preferably 5 to 20 MPa (50 to 200 bar). The components which may be present in the aqueous phase include bulking agents such as maltodextrin, dairy proteins, inulin and polydextrose which are used together with thickeners and gelling agents. Thickeners include, but are not limited to, LBG, guar, xanthan alginate, Konjac, starches (native and modified), CMC, MCC. A typical composition may contain a total of 0.5 to 3 wt.% of these components. Typical gelling agents include, but are not limited to, gelatin, carrageenan, alginate, pectin, gel forming starches or synergistic combinations of gums selected by those skilled in the art. The aqueous phase can be of a gelled nature or have enough viscosity to provide the body and structure into which the destabilised oil droplets is contained. The total content of these components is preferably 0.5 to 5 wt.%. Heat treatment of the emulsion is desirable to confer microbiological stability to the product and for products which have a pH value of more than about 4 they are preferably heated to at least 80°C and preferably above 85°C. A plate heat exchanger or scrape surface heat exchanger is suitable for this purpose. The product may be filled hot or cold. After filling the products are preferably stored under refrigeration. The following formulations are shown to illustrate the invention: Example 1 % Hydrogenated coconut oil 3.5 Hydrogenated palm oil 0.6 Secondary Emulsifier 0.8 CMC [Carboxy methyl cellulose] 0.52 Gelatin 0.56 Konjac mannan 0.01 Dairy protein [Simplesse 100®] 2.0 Skimmed milk powder 6.02 Poly fructose [Raftiline HP] 6.0 Salt 1.0 Potassium sorbate 0.1 Beta carotene dispersion 0.03 Water 78.86 The fat content of this product is 4.9%. The secondary emulsifier was added to the fats and melted to 65-70°C. The rest of the dry ingredients were added to water at 45-50°C. The molten fat phase was added to the aqueous phase with agitation to keep the fat in suspension prior to further processing and to allow the dry ingredients to swell and hydrate. The β-carotene solution is added to this coarse oil in water emulsion. The pH was adjusted to 6.6-6.7 using a buffer salt such a tetrasodium pyrophosphate. The emulsion was heated using a plate heat exchanger to 85°C and passed through a 2 stage high pressure piston homogeniser at 200 Bar and 50 Bar. The product was then heated again to achieve a temperature of 120°C also using a plate heat exchanger. The product was cooled to 85°C using the plate exchanger prior to hot filling. Example 2 Example 1 was repeated with the exception that after cooling to 85°C, the product was further cooled to 10°C before filling using a scrape surface heat exchanger e.g. Schroeder Kombinator. Example 3 Example 1 was repeated with the exception that the coconut oil was replaced with a fractionated palm oil containing a high percentage of solid fat at 20°C. Examples 4-6 The fat content was reduced as follows and the hydrocolloid levels were adjusted: 4 % 5 % 6 % Fractionated palm oil 1.6 0.6 0.0 Hydrogenated palm oil 1.6 1.6 1.2 Secondary Emulsifier 0.8 0.8 0.8 CMC [Carboxy methyl cellulose] 0.5 0.5 0.5 Gelatin 0.8 1.0 1.2 Konjac mannan 0.015 0.02 0.025 Dairy protein [Simplesse 100®] 2.0 2.0 2.0 Skimmed milk powder 6.0 6.0 6.0 Poly fructose [Raftiline HP] 6.0 6.0 6.0 Salt 1.0 1.0 1.0 Potassium sorbate 0.1 0.1 0.1 Beta carotene dispersion 0.03 0.03 0.03 Water 79.555 80.35 81.143 Fat content 4.0% 3.0% 2.0%

Claims: An edible emulsion comprising an aqueous dispersion of an edible fat or oil component and an emulsifier system, characterised in that the fat or oil component is present in an amount of 2 to 5 wt.%, based on the total emulsion, and in that the emulsifier system is a two-component or multi-component system which comprises: a primary emulsifier comprising one or more components selected from proteins, skim milk powder, polysorbates, Datem, Citrem, sucrose esters, octenyl succinic acid (OSA) starches and gum arabic, acting to stabilise the emulsion, and a secondary emulsifier acting to destabilise the oil-in-water emulsion to create a substantially semi-solid plastic matrix, said secondary emulsifier including one or more mono- or diglycerides or polyglycerol esters, prepared from unsaturated or partially unsaturated fats. An edible emulsion according to claim 1 characterised in that the fat or oil content is at least 2 wt.%, based on the total emulsion. An edible emulsion according to claim 1 or claim 2 characterised in that it contains 0.1 to 10 wt.% of said primary emulsifier, based on the total emulsion. An edible emulsion according to any preceding claim characterised in that said primary emulsifier comprises one or more of caseinate, whey protein, milk powder and gelatin. An edible emulsion according to any preceding claim wherein said secondary emulsifier also includes one or more components selected from polysorbates, organic acid esters of mono- and diglycerides, propylene glycol esters, stearyl lactylates, lecithin and sucrose fatty acid esters. An edible emulsion according to any preceding claim characterised in that it contains from 0.2 to 2 wt.% of said secondary emulsifier, based on the total emulsion. An edible emulsion according to any preceding claim characterised in that it contains 0.5 to 5 wt.% of a gelling agent. An edible emulsion according to any preceding claim characterised in that it contains 0.5 to 3 wt.% of a thickening agent. A method of making an edible emulsion according to any preceding claim which comprises melting the fat or oil component, adding the primary emulsifier and any other dry ingredients to water, adding the secondary emsulifier to the fat or oil component and/or to the aqueous phase, adding the molten fat or oil to the aqueous phase with agitation to keep the fat or oil in suspension as small uniform droplets and processing the suspension to allow the dry ingredients to swell and hydrate. A method according to claim 9 comprising the further step of heating the emulsion and homogenising it under pressure prior to cooling.

Inventors: ASSMANN KATHRIN ANGELIKA, FOLEY THOMAS, MERRICK WILLIAM GEORGE, REINEKE STEFANIE, ASSMANN, KATHRIN ANGELIKA, FOLEY, THOMAS, MERRICK, WILLIAM GEORGE, REINEKE, STEFANIE
Applicants: HAHNTECH INTERNAT LTD, HAHNTECH INTERNATIONAL LIMITED
Application year: 2001
Main classification: A23D7
IPC codes: A23D7