A PROCESS FOR PRODUCING A BUTTER-LIKE W/O EMULSION SPREAD

Abstract: A process for producing a butter-like w/o emulsion spread, wherein (a) an o/w emulsion cream is produced from an aqueous phase and a high solids fat containing at least 25% crystallized fat at a temperature within the range of 5-10°C; b) a w/o emulsion is produced from an aqueous phase and the remainder of the fat of the fatty phase; c) both emulsions are cooled to a temperature achieving crystallization of at least part of the fat present in each emulsion; d) the crystallized emulsions are mixed and further cooling and working of the mixture of both emulsions are carried out to achieve further crystallization and obtain a w/o emulsion spread containing fat globules of an average size not exceeding 20 micrometer and preferably ranging from 3-6 micrometer.

Description: The present invention relates to a process for producing a butter-like w/o emulsion spread, particularly a spread with a reduced or low fat content. More particularly, the present invention relates to a process for producing a butter-like w/o emulsion spread containing a fat with a relatively high level of fat solids, part of said fat being present in granular form. In the context of the present invention we mean by butter-like spreads : plastic, cool melting products giving an oral response, particularly a palate breakdown which closely approaches that of dairy butter. By a fat with a high level of fat solids we mean fats which at refrigerator temperatures (5-10°C) have a level of crystallized fat higher than 25% and preferably from 40-85%. By reduced fat spreads we mean spreads containing less than 70% fat and preferably containing 55-65% fat, whereas by low fat spreads we generally mean spreads containing 20-55%, preferably 30-50% fat. A major problem with reduced fat spreads using conventional fat blends is that the palate melting behaviour is clearly different than that of higher fat products such as butter. The most obvious reason for this is the reduced amount of solid fat in the product. An advantage of the fats used in this invention is that the amount of solid fat they confer in the reduced fat spread approaches that to be found in conventional high fat products. According to the present invention there is provided : A process for producing a butter-like w/o emulsion spread containing less that 70% wt fat, starting from a thickenable or gellable aqueous phase and a fatty phase, characterized in that : a) an oil-in-water emulsion cream is produced from an aqueous phase and a high solids fat containing at least 25% crystallized fat at a temperature within the range of 5-10°C, and said oil-in-water emulsion is cooled to a temperature at which at least part of the high solids fat is crystallized; b) separately from step (a) a water-in-oil emulsion is produced from an aqueous phase and the remainder of the fat of the fatty phase, and said water-in-oil emulsion is cooled to a temperature at which at least part of the remainder of the fat is crystallized; and c) the at least partially crystallized emulsions obtained by step (a) and step (b) are combined, mixed, cooled further and worked to achieve further crystallization of the fatty phase and obtain a water-in-oil emulsion spread containing fat globules of an average size not exceeding 20 micrometers and preferably ranging from 3-6 micrometers. The high solids fat is preferably concentrated in the o/w emulsion cream. In order to stabilize the w/o emulsion spreads against exudation of water, their aqueous phase is thickened or gelled with a thickening or gelling agent which can be incorporated in either the o/w emulsion or in the w/o emulsion or in both the o/w and the w/o starting emulsions. Such gelling and thickening agents may include any of the substances well known in the art. However, those are preferred which are setting slowly or whose setting can be delayed by controlling the temperature and the shear conditions during processing. Preferred thickening/gelling agents are gelatin, i-carrageenan calcium alginate, milk proteins or mixtures thereof. The aqueous phase of the spreads preferably contains 1-15 wt.% milk protein such as sodium caseinate and 1-5 wt.% gelatin, based on the aqueous phase. Setting of the aqueous phase is preferably delayed until at least 5% and preferably 20-80% of the crystallizable fat has crystallized. In a preferred embodiment of the process according to the invention both the w/o and the o/w emulsions are cooled independently in a Votator® A unit operating at 500-1500 r.p m., the super-cooled emulsions are subsequently brought together in a Votator® C unit operating at 1500-3000 r.p.m. whereby crystallization of the fat takes place and setting the aqueous phase is initiated. Optionally the emulsion can be further processed through a second Votator® C unit operating at 500-1500 r.p.m., in which crystallization and setting are completed. The o/w emulsion can be mixed in variable amounts, in line with the w/o emulsion. Generally, the ratio of o/w emulsion to w/o emulsion will vary from 1:5 to 1:1 preferabIy from 1:5 to 2.5:5. The fat in the fatty phase preferably contains suitable quick crystallizing, sharp melting fats, i.e. fats which contribute to avoidance of waxiness on consumption of the spreads because, at body temperature, they do not contain any crystallized fat. Suitable quick-crystallizing fats include hydrogenated lauric fats such as palmkernel oil, coconut oil, babassu oil, murumuru oil, ouricuri oil, which are rich in C₁₂-C₁₄ fatty acids, further tallow fat or fractions thereof, butterfat or fractions thereof or mixtures of said fat. Preferably, the quick-crystallizing fat constitutes at least 10% wt. and preferably 20-80% wt. based on the total fat. Formation of fat globules and fat granules is promoted by the presence in the fatty phase of a high solids fat displaying the following fat solids profile expressed in percentages determined by nuclear magnetic resonance (NMR) at the indicated temperatures: N₅ = 40-90 N₃₀ = 0.1-15 N₁₀ = 25-85 N₃₅ = 0-5 N₂₀ = 15-35 Appropriate fats (i) to be incorporated in the fatty phase comprise wet- and dry-fractionated fractions of palm oil, characterized by the following triglyceride composition: SSS triglycerides : 1-9 wt.%; SOS triglycerides : 30-75 wt.%; SSO triglycerides : 3-12 wt.%, the remainder of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides, wherein "S" = saturated fatty acids, "O" = mono-unsaturated fatty acids and "L" = polyunsaturated fatty acids. Suitable is a wet-fractionated palm mid-fraction, characterized by the following triglyceride composition: SSS = 1-5 wt.%; SOS = 50-75 wt.%; SSO = 3-9 wt.%, the remainder of the triglycerides of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides, or dry fractionated palm mid-fraction, characterized by the following triglyceride composition : SSS = 1-9 wt.%; SOS = 30-50 wt.% SSO = 5-12 wt.%, the remainder of the triglycerides of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides. The preparation of wet and dry fractionated palm mid-fractions is well known in the art (see for instance US 4 203 095, US 3 012 891, GB 827 172, GB 1 431 781 and GB 1 390 936. In a preferred embodiment of the process according to the invention, the high solids fat, particularly the quick crystallizing, sharp melting fats, are concentrated in the starting o/w emulsion cream. In general the fat phase will comprise 10-80 wt.% of high solids fat and 90-20 wt.% of other oils and fats of a triglyceride composition such that the total fat blend has the following fat solids profile : N₁₀ = 20-70 N₂₀ = 10-40 N₃₀ = 0.1-5 N₃₅ = 0-5 The process according to the invention as outlined above leads to spreads spreadable at refrigerator temperatures which have good plasticity and organoleptic properties reminiscent of dairy butter. It is believed that this is due both to the formulation criteria and to the processing criteria outlined above. It is also believed that concentration of high solids fats, particularly the quick crystallizing, sharp melting fat, in the cream promotes the formation and transfer of granulated fat to the continuous fat phase. The presence of granules is believed to soften resultant products with respect to those produced by conventional type processing and enhance the plastic character of the products, while maintaining the high solids properties if the overall fat blend, resulting in a product with a cool and quick melting character. Hence higher fat solids in the products than conventionally employed with reduced fat spreads can be used, approaching or matching the figure normally found in the 80% fat products. Product melting characteristics are thus enhanced without the unwanted too high hardness values at spreading temperatures. Distribution of the higher melting triglycerides of the structural fat (high solids fat) as small granules of an average size not exceeding 20 micrometer, and more preferably not exceeding 10 micrometer, allow the cool melting properties of the fat blend to be appreciated while maintaining the hardness of the product within acceptable ranges, i.e. values not exceeding 5,000 g/cm² and preferably ranging from 1,000 to 4,000 g/cm². The invention will be illustrated in the following Examples : Example 1 A w/o pre-mix emulsion of the following composition was prepared by mixing the ingredients at 60°C. The fat blend consisted of a mixture of 60% soybean oil hydrogenated to a melting point of 38°C and 40% of a randomly interesterified mixture of 40% palm oil and 60% palmkernel oil. An o/w emulsion of the following composition was prepared : The cream was produced at 60°C using a minisonic homogenizer giving an average oil droplet size of about 6 micrometer. The gelatin was added after homogenization of all other ingredients of the cream. The cream was first fed into a Votator® A unit operating at 1,000 r.p.m., followed by a Votator® C₁ crystallizer unit operating at 1,000 r.p.m. Precrystallized cream containing at least 50 wt.% solid fat left the C₁ unit at 5°C and was mixed in line with the pre-crystallized w/o emulsion (containing about 7 wt.% fat solid), which was first fed into a Votator A₂ unit operating at 1,000 r.p.m. (outlet temperature 13°C) and subsequently fed into a Votator ® C₂ unit operating at 2,000 r.p.m. The mixture of the two emulsions in the Votator® C₂ unit was allowed to crystallize further and the aqueous phase to set. The temperature of the emulsion leaving the C₂ unit was about 17°C. This emulsion was further fed into a Votator® C₃ unit operating at 1,000 r.p.m. The temperature of the product leaving this unit was 10°C and was ready for packaging. The average residence time in the A unit was 3 sec. and in the C units 3 min. The proportion of cream to w/o emulsion was 1:2. Example 2 A w/o (pre-mix) emulsion was produced following the procedure of Example 1. This pre-mix had the following composition: An o/w emulsion cream (pre-mix) was produced following the procedure of Example 1. This cream had the following composition : The cream and the w/o emulsion were blended in line in the ratio 1:1. The resulting spread had the following approximate composition : The hardness (C value) of the product measured at 5°C was about 1,000 g/m². The product was fairly plastic and had good spreadability at refrigerator temperature. On consumption, the product was perceived as cool. Photomicrographs of the product were taken, using phase contrast at a magnification of 400. The water drops and granules appeared as bright and dark spots. The average size of the granules was approx. 5 micrometer. The processing line can be illustrated as follows : The resulting product had the following approximate composition : The line used was the same as employed in Example 1. The average residence time in the A unit was 3 sec. and in the C units 3 min. The level of crystallized fat in the pre-crystallized w/o emulsion was at least 5% based on fat, before the aqueous phase was allowed to set. The level of crystallized fat in the pre-crystallized o/w emulsion cream was at least 108 based on fat, before the aqueous phase was allowed to set. The hardness (C value) of the product measured at 5°C was approx. 1700 g/cm². The product was fairly plastic and had good spreadability at refrigerator temperature. On consumption, the product was perceived as cool. Photomicrographs of the product were taken, using phase contrast at a magnification of 400. The water drops and granules appeared as bright and dark spots. The average size of the granules was approx. 5 micrometer. Example 3 A w/o (pre-mix) emulsion was produced, following the procedure of Example 1. This pre-mix had the following composition : and buffered to a pH of 6 with a mixture of lactic and citric acids. An o/w emulsion cream (pre-mix) was produced, following the procedure of Example 1. This cream had the following composition : and buffered to a pH of 6 with a mixture of lactic and citric acids. The cream and the w/o emulsion were blended in line in the ratio 1:1. The processing line can be illustrated as follows : The product was fairly plastic and had good spreadability at refrigerator temperature. On consumption, the product was perceived as cool. Comparative Example Example 3 was repeated without the granulation process. In this Comparative Example the fat phase of the cream and that of the w/o emulsion were combined to obtain a single fat phase. This fat phase was combined with the aqueous phase ingredients to give a single w/o pre-mix. This pre-mix was processed by passage along a processing line illustrated as follows : The products obtained from Example 3 and the Comparative Example were compared. Although the products had similar C-values (hardness), the product of Example 3 was much more plastic on spreading. At 5°C, the product of Example 3 gave a collar value of 2, whereas the product of the Comparative Example gave a collar value of 5.

Claims: A process for producing a butter-like w/o emulsion spread containing less that 70%wt fat, starting from a thickenable or gellable aqueous phase and a fatty phase, characterized in that : a) an oil-in-water emulsion cream is produced from an aqueous phase and a high solids fat containing at least 25% crystallized fat at a temperature within the range of 5-10°C, and said oil-in-water emulsion is cooled to a temperature at which at least part of the high solids fat is crystallized; b) separately from step (a) a water-in-oil emulsion is produced from an aqueous phase and the remainder of the fat of the fatty phase, and said water-in-oil emulsion is cooled to a temperature at which at least part of the remainder of the fat is crystallized; and c) the at least partially crystallized emulsions obtained by step (a) and step (b) are combined, mixed, cooled further and worked to achieve further crystallization of the fatty phase and obtain a water-in-oil emulsion spread containing fat globules of an average size not exceeding 20 micrometers and preferably ranging from 3-6 micrometers. A process according to Claim 1, wherein high solids fat is concentrated in the cream. A process according to Claim 1, wherein the aqueous phase of at least one of the starting emulsions contains a thickening or gelling agent. A process according to Claim 3, wherein setting of the aqueous phase is delayed until a stage where at least part of the fat has crystallized. A process according to Claim 4, wherein gelling is delayed by using a slow setting gelling agent or by applying temperature and shear conditions preventing 35 setting of the gellable aqueous phase. A process according to Claim 4, wherein the aqueous phase is thickened/gelled with gelatin, i-carrageenan, calcium alginate, milk protein or mixtures thereof. A process according to Claim 4, wherein the aqueous phase of the spread contains 1-15 wt.% of milk protein, preferably sodium caseinate, and 1-5 wt.% gelatin based on the aqueous phase. A process according to Claim 4, wherein setting of the aqueous phase is delayed until at least 5% and preferably 20-80% of the crystallizable fat has crystallized. A process according to Claim 1, wherein pre-crystallization of the emulsion is carried out in a Votator® A unit operating at 500-1500 r.p.m. and mixing of the emulsion and complete crystallization are 20 carried out in Votator® C unit or in a sequence of 2 Votator® C units. A process according to Claim 9, wherein mixing is first achieved in a first Votator® C unit operating at 1500-3000 r.p.m., whereafter further working is continued in a second Votator® C unit operating at 500-1500 r.p.m. A process according to Claim 1, wherein the ratio o/w emulsion cream : w/o emulsion ranges from 1:5 to 1:1, preferably from 1:5 to 2.5:5. A process according to Claim 1, wherein the high solids fat comprises quick-crystallizing, sharp-melting fats selected from hydrogenated lauric fats or fractions thereof, tallow or fractions thereof, non-hydrogenated lauric fats, butterfat or fractions thereof and mixtures of said fats, said quick-crystallizing, sharp-melting fats being preferably incorporated in the cream. A process according to Claim 1, wherein the quick crystallizing fat constitutes at least 10 wt.% and preferably 20-80 wt.% based on the total fat. A process according to Claim 1, wherein a fatty phase is used which contains a high solids fat displaying the following fat solids profile expressed in percentages determined by nuclear magnetic resonance (NMR) at the indicated temperatures: N₅ = 40-90 N₃₀ = 0.1-15 N₁₀ = 25-85 N₃₅ = 0-5 N₂₀ = 15-35 A process according to Claim 1, wherein the fat phase comprises 10-80 wt.% of high solids fat and 90-20 wt.% of other oils and fats of a triglyceride composition such that the total fat blend has the following fat solids profile : N₁₀ = 20-70 N₃₀ = 0.1-5 N₂₀ = 10-40 N₃₅ = 0-5 A process according to Claim 1, wherein the fatty phase comprises a fat (i) characterized by the following triglyceride composition : SSS triglycerides : 1-9 wt.%; SOS triglycerides : 30-75 wt.%; SSO triglycerides : 3-12 wt.%, the remainder of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides. A process according to Claim 16, wherein fat (i) is a palm mid-fraction characterized by the following triglyceride composition : SSS = 1-5 wt.%; SOS = 50-75 wt.%; SSO = 3-9 wt.%, the remainder of the triglycerides of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides. A process according to Claim 16, wherein fat (i) is a palm mid-fraction, characterized by the following triglyceride composition : SSS = 1-9 wt.%; SOS = 30-50 wt.%; SSO = 5-12 wt.%, the remainder of the triglycerides of fat (i) up to 100 wt.% consisting of SOO and SLS triglycerides.

Inventors: MORAN,DAVID PATRICK JOSEPH
Applicants: UNILEVER NV
Application year: 1987
Main classification: A23D7
IPC codes: A23D7, A23C15