A low fat spread

Abstract: A low fat spread having a low pH is prepared from an aqueous phase comprising water, a gelling agent, salt, lactic acid and fermented reconstituted skim milk solids and a fat phase comprising milk fat, monoglyceride emulsifier and a colouring agent. The aqueous and fat phases are mixed together to form a water-in-oil emulsion which is pumped by a positive displacement pump through a scraped surface heat exchanger to form a spread. The relatively low content of milk fat solids as a source of protein yields a low fat spread with a protein content in the aqueous phase of 0.1% to 0.4% which is easily processed and which has good organoleptic properties.

Description: The invention relates to a low fat spread and to a process for preparing such a spread. More particularly, the invention relates to a low fat spread of the type comprising a continuous fat phase and a dispersed proteinaceous aqueous phase gelled with the gelling agents known from "RESEARCH DISCLOSURE, no. 192, (1980), abst. no. 19221. GB-A 2 084 171 discloses a process for producing a low fat spread. In the process described therein an initial emulsion oil-in-water is formed and must be further inverted to an emulsion of water-in-oil type during processing. EP-A-0 271 132 discloses an edible dispersion which comprises an aqueous phase and a fat phase. The aqueous phase is a gel-forming composition comprising carrageenin and a cation A of a type and in a concentration effective to cause the gel-forming composition to have a transition mid-point temperature below 50°C. In the process described therein an oil-in-water emulsion is prepared from the fat phase and the aqueous phase composition. This emulsion is than inverted to a water-in-oil emulsion by subjecting it to working and cooling. In "RESEARCH DISCLOSURE. No. 249. (1985. Abst. No. 24901)" a very high protein spread is described having a proteinaceous aqueous phase with 7% casein and 1% skimmed milk powder. The pH of the emulsion must be greater than 6.0. EP-A-0 098 174 discloses a spread which uses particular types of fat, none of which are used in the present invention. FR-A-2 330 326 discloses a spread which is entirely different from the spread of the present invention. For example, the level of protein is higher than the range specified in the present invention. A thickener rather than a gelling agent is used. EP-A-0 293 980, which is to be considered as prior art according to article 54(3) EPC, discloses a process for the preparation of a low fat spread having a continuous fat phase and a dispersed proteinaceous aqueous phase. The process involves a phase invertion from an oil-in-water emulsion to a water-in-oil emulsion. In the paper entitled "Low Calorie Spreads in Europe" presented at the international Conference on Oils, Fats and Waxes, Auckland, New Zealand 13-17 February, 1983, a low fat spread is described which has between 0.2% and 0.3% whey protein in the aqueous phase. The pH of the aqueous phase is stated to be between 4.7 and 6.3. As whey protein is stable at the pH described the protein will remain dissolved. The present invention is as described in the claims. We have found that a protein content of the aqueous phase in this range gives a low fat spread which has particularly good organoleptic properties. In one embodiment of the invention the low fat spread is a lactic spread having a low pH preferably in the range 4.0 to 5.6, most preferably in the range of 4.7 to 4.9. In one embodiment of the invention the gelling agent comprises gelatin, sodium alginate or any other suitable gelling agent. In another embodiment of the invention the gelling agent is present in an amount of between 3.25% and 5%, most preferably approximately 3.33% by weight of the aqueous phase. We have found that this proportion of gelatin in relation to the protein content gives favourable processing and organoleptic properties. In one embodiment of the invention the spread includes an emulsifier such as a monoglyceride which is preferably present in an amount of from 0.1% to 1%, most preferably, approximately 0.5% by weight of the product. In another aspect the invention provides a process for preparing a low fat spread according to the invention comprising the steps of preparing an aqueous phase comprising water, a gelling agent and salt, preparing a fat phase, and combining the aqueous and fat phases to form a water-in-oil emulsion. In a preferred embodiment of this aspect of the invention the aqueous phase is prepared by preparing a first solution of water and gelling agent and a second solution of water and salt and subsequently combining and mixing the two solutions. In one embodiment of the invention lactic acid and fermented reconstituted skim milk solids are added to the combined salt and gelling agent solutions to form the aqueous phase. Preferably the water-in-oil emulsion formed is pumped using a positive displacement pump through a plate heat exchanger unit, preferably a scraped surface heat exchanger. The invention will be more clearly understood from the following description thereof given by way of example only. Unless otherwise stated all percentages are by weight. Example 1 A low fat spread was prepared from the following ingredients. Aqueous phase (percentages are by weight of the total aqueous phase). Water (added as liquid) 90.04% Gelatin 3.33% Salt (NaCl) 0.83% Preservative (potassium sorbate) 0.166% Lactic acid 0.79% Fermented reconstituted skim milk 4.85% Fat Phase : (Percentages are by weight of the fat phase) Milk fat 98.73% Monoglyceride emulsifier 1.25% Colouring agents (vitamin A) 0.02% Aqueous Phase To prepare the aqueous phase the gelatin was first dissolved in approximately 30% of the water which was added as liquid at a temperature of approximately 73°C. The salt and preservative were dissolved in sufficient water for dissolution at a temperature of approximately 73°C. The gelatin and salt solutions were combined and mixed, with water added as liquid, added as required and cooled to approximately 40°C. 22% reconstituted skim milk powder was inoculated with bacterial culture and subsequently incubated. The bacterial culture may be starter type Fr 19 and starter type 4/25, available from the Nederlands Institute Voor Zuivelonderzoek and are preferably grown separately. Starter type 4/25 contains Streptococcus diacetilactis as aroma bacterium. Starter type Fr 19 is a Leuconostoc-containing B-starter. The reconstituted skim milk power and bacteria were incubated for approximately 24 hours until a pH range of 5.0 to 5.2 is reached. 4.85% concentration (based on the aqueous base) of this product which corresponds to approximately .35% protein of the aqueous phase together with the lactic acid were then added to the combined gelatin and salt solutions at a temperature of approximately 40°C. After preparation, the pH of the aqueous phase is in the range of 4.3 to 5.2, preferably 4.6 to 4.9. If desired to achieve flavour properties, further diacetyl may be added to the aqueous phase. Fat Phase The milk fat of the fat phase is typically dehydrated milk fat. To prepare the fat phase the fat is melted at approximately 80°C and the emulsifier and colouring agent are added while mixing the fat. Preparation of emulsion The aqueous phase and the fat phase are then combined by adding the aqueous phase to the fat phase slowly while agitating the mixture to achieve uniform mixing to form a water-in-oil type emulsion. The emulsion is then pumped using a positive displacement pump through a plate heat exchanger such as a scraped surface heat exchanger such as that sold under the name Votator or Perfector to form a low fat spread. The low fat spread prepared by the process has solid characteristics somewhat similar to that of butter. To make the spread more readily spreadable a vegetable oil may be added. Trials have indicated that the low fat spread has very good organoleptic properties. The final product of the process has the following constituents based on percent by weight of the final product. Water (added as liquid) 54.00% Gelatin 2.00% Salt (NaCl) 0.5% Preservative (potassium sorbate) 0.10% Lactic acid 0.50% Fermented reconstituted skim milk 2.91% (of which protein constitutes 0.24%) Milk fat 39.50% Monoglyceride emulsifier 0.50% Colouring agent (vitamin A) 0.005% We have found that the amount of protein used is of particular importance when using skim milk solids. We have found that a small quantity of protein is essential for flavour release however, the amount of protein used is low, most preferably, below 0.5% to ensure that phase inversion does not occur prior to passing through the plate heat exchanger. This is particularly important in acidic conditions as we have found that in acidic conditions high levels of milk protein may cause phase inversion. It will be appreciated that any suitable gelling agent may be used. For example, instead of gelatin, sodium alginate may be used as a gelling agent. In this specification gelling agents are not regarded as being proteins. At the level of 0.1 to 0.4% by weight of the aqueous phase constituting protein the preferred gelling agent range is 3.25 to 5%, most preferably 3.33%, of the aqueous phase. A size analyses of the undissolved protein particles in the aqueous phase indicated an average particle size in excess of 10 micrometers.

Claims: A low fat spread, comprising a continuous fat phase, and a dispersed proteinaceous aqueous phase gelled with a gelling agent, the protein of the aqueous phase being derived from fermented reconstituted skim milk and being present in an amount of from 0,2 % to 0,4 % by weight of the aqueous phase, wherein the fat phase and the aqueous phase are combined to form a water-in-oil-emulsion and wherein the aqueous phase contains an acid such that the pH of the aqueous phase is in the range of from 4.0 to 5.6 and wherein undissolved protein particles are present having an average particle diameter in excess of 10 µm. A low fat spread as claimed in claim 1 characterised in that the protein content in the aqueous phase is approximately 0.38% by weight of the aqueous phase. A low fat spread as claimed in claim 1 or 2 characterised in that the source of protein is fermented reconstituted skim milk solids. A low fat spread as claimed in any of claims 1 to 3 characterised in that the pH of the aqueous phase is in the range of 4.7 to 4.9. A low fat spread as claimed in any of claims 1 to 4 characterised in that the gelling agent is selected from gelatin and sodium alginate and is present in an amount of between 3.25% and 5% by weight of the aqueous phase. A low fat spread as claimed in claim 5 wherein the gelling agent is present in an amount of approximately 3.33% by weight of the aqueous phase. A low fat spread as claimed in any preceding claim wherein the spread includes an emulsifier such as monoglyceride which is present in an amount of from 0.1% to 1% by weight of the product. A process for preparing a low fat spread as claimed in any preceding claim comprising the steps of preparing an aqueous phase comprising water, a gelling agent, an acid, and salt, preparing a fat phase and combining the aqueous and fat phases to form a water-in-oil emulsion. A process as claimed in claim 8 characterised in that the aqueous phase is prepared by preparing a first solution of water and gelling agent and a second solution of water and salt and subsequently combining and mixing the two solutions. A process as claimed in claim 8 or 9 characterised in that lactic acid and fermented reconstituted skim milk solids are added to the combined salt and gelling agent solutions to form the aqueous phase. A process as claimed in any of claims 8 to 10 wherein the water-in-oil emulsion formed is pumped by a positive displacement pump through a plate heat exchanger unit.

Inventors: CASS MICHAEL, SWEENEY KEVIN, CASS, MICHAEL, SWEENEY, KEVIN, SWEENEY, KEVIN 7 PRIORY AVENUE LANDSEND
Applicants: WATERFORD COOP DAIRY, WATERFORD CO-OPERATIVE DAIRY AND TRADING SOCIETY LIMITED
Application year: 1989
Main classification: A23D7
IPC codes: A23C15, A23D7