WO2003049548A1

WO2003049548A1 - Emulsified food compositions

Info

Publication number: WO2003049548A1
Application number: PCT/EP2002/012855
Authority: WO
Inventors: Ingrid Anne Marie Appelqvist; Jennifer Elizabeth Homan; Mark Emmett Malone
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Lever Limited
Priority date: 2001-12-12
Filing date: 2002-11-18
Publication date: 2003-06-19
Also published as: AU2002349035A1

Abstract

Water-continuous emulsified (food) compositions comprising a water-soluble tastant capable of imparting a sweet, salty, sour, bitter or umami taste to the food composition, e.g. compositions of the type of cold sauces (e.g. dressings, mayonnaises, and vinaigrettes), hot sauces (e.g. sauce béchamel, cheese sauce, sauce hollandaise, mushroom sauce, etcetera). The compositions according to the invention have a reduced taste impression.

Description

EMULSIFIED FOOD COMPOSITIONS

Field of the invention

The present invention relates to water-continuous emulsified (food) products comprising a water-soluble tastant capable of imparting a sweet, salty, sour, bitter or umami taste (e.g. sugar, salt, acid, etcetera) to the composition. More in particular, this invention relates to products of the type of cold sauces (e.g. dressings, mayonnaises, vinaigrettes), hot sauces (e.g. sauce bechamel, cheese sauce, sauce hollandaise, mushroom sauce, etcetera).

Background of the invention

Many emulsified food compositions like dressings, mayonnaises, as well as sauces that contain a considerable proportion of water are made shelf stable by acidifying the water phase. If the water phase has a pH of below 4.8, preferably below 4.2, or even lower, a keepability is obtained that reduces the need for other preservation techniques, such as sterilising, adding antimicrobial agents, or other. This is a benefit in so far that such food compositions may have a good texture not affected by sterilising techniques, and that no antimicrobial agents have to be declared.

Disadvantage of this technique is that the compositions concerned acquire a strong acidic taste. Although mayonnaises and dressings do have a sour taste in general, there is a demand for more mild tasting mayonnaises, dressings, vinaigrettes and the like. The problem of a too acidic taste is even more important for hot sauces, such as mushroom sauce, bechamel sauce, cheese sauce, various oriental-style sauces and the like. The market for such sauces (pour-over sauces, cook-in sauces, simmer sauces, and the like) is ever increasing, and there is a demand for such sauces which do have a water phase with a low pH for preservative purposes, but which do not taste (too) acidic.

Likewise, some emulsified food compositions contain a considerable amount of salt for preserving purposes (by reducing the water activity), but should not taste too salty. The same can be said for emulsified food compositions that contain a considerable amount of sugar: such compositions should not taste too sweet.

There are also compositions available that contain peptides (e.g. of hydrolysed proteins) and amino acids that may also contain peptides or amino acids that may cause an off-taste; e.g. bitterness. For many of the compositions described above it may be desired to suppress or reduce one or more of the perceived tastes which are the result of the total concentration of water-soluble tastants present in the composition, like salt, acids, amino acids, sugars, etcetera.

In order to achieve to reduce acid perception, various measures have been proposed in the past. Examples of this are: addition of sugars, increasing viscosity, use of less-sour tasting acids, etcetera. None of these techniques is fully satisfactory, and there is a demand for water-continuous emulsified food compositions in which the water phase has a pH of less than 7.0, and which have a reduced acid perception.

Similarly, measures have been taken to reduce e.g. an overly sweet taste when a lot of sugar is present in the composition (e.g. required for structuring reasons or mouthfeel). Again such measures are not always satisfactory, and the same can be said for reduction of salty taste, or bitterness, or others.

US 5,332,595 describes W/OΛ/V and OΛΛ//O emulsions for reduced fat applications, in which a gelatinous layer is provided at the interfacial region between an internal aqueous or oil phase and an intermediate oil or aqueous phase, respectively, of the multiple emulsion.

US 5,322,704 describes the use of multiple emulsions for low fat emulsified food compositions.

EP 141477 describes W1/OΛΛ/2 duplex emulsions which comprise various tastants. In example VII sucrose, salt, and 10% acetic acid are present in such concentrations that W1 (internal water phase) and W2 (external water phase) are isotonic for these components.

Summary of the invention

There is a need for water-continuous, emulsified food compositions that have a reduced perception of primary taste components like sugar, salt, acid, bitterness, in particular in cases wherein the total amount of such taste-imparting substances (hereinafter called "tastants") is not reduced.

It has now been found that such objectives can be met (at least in part) by an edible composition compπsing a W1/OΛΛ 2 duplex emulsion wherein both water phases W1 (dispersed water phase) and W2 (continuous water phase) comprise at least one water- soluble tastant in both of the water phases and wherein said waterphases W1 and W2 are substantially isotonic for said tastant and wherein the composition does not comprise as sole tastants a combination of salt, sucrose and 10% acetic acid.

In other words, when compared with an ordinary water-continuous emulsion (O/W), the duplex emulsions according to the invention may give a reduced taste impression for those tastants which are present in both W1 and W2, even when the total amounts of water, oil, and tastant concerned are kept equal. Thus, a model W/O/W duplex emulsion of weight composition 50/30/20, comprising 5 grams citric acid per 100 gram water, will give a reduced acid taste upon consumption when compared with a simple O/W control emulsion of composition 30/70, also comprising 5 grams citric acid per 100 gram water.

Isotonic in the context of the invention is to be understood as a substantial similar concentration for the compound concerned in the water phases W1 and W2.

Duplex W/O/W emulsions are multiple emulsions in which the two aqueous phases W1 and W2 are separated by an immiscible oil phase. In common nomenclature, the dispersed inner water phase is referred to as W1 and the outer water phase is referred to a W2.

Without wishing to be bound by theory, it is believed that the emulsions according to the invention "shield" part (the part in the inner water phase W1) of the tastant concerned (e.g. salt ions, or dissociated acid) from the taste buds because the duplex emulsion is fairly stable (as both the inner W1 and outer W2 aqueous phases are isotonic and the hydrophilic contents of the inner aqueous phase are not or not completely released during the time scales of eating). In other words, the tastant in the inner water phase presumably reaches the tastebud in a reduced extent, thus giving a reduced overall taste impression. Thus, by increasing the inner W1 phase volume and consequently decreasing the W2 phase volume it is possible to reduce the perceived intensity. However, this is speculative, and the action may be different, nevertheless the effect is clear.

One of the primary concerns with duplex emulsions preventing their commercial use is their tendency towards instability during storage and consumption. Factors contributing to emulsion instability are osmotic gradients leading to swelling and rupture of the duplex structures, coalescence of the internal aqueous droplets, coalescence of the internal water droplets with the outer aqueous phase, reverse micelle transport of the solutes through the oil phase and coalescence of the oil droplets. In this invention the stability is addressed by using the appropriate emulsifiers at the internal W1/O and external O W2 interfaces. Having isotonic levels of tastants in W1 and W2 water phases provides an advantage of improved stability during storage and consumption.

Detailed description of the invention

The invention is limited to tastants that are better water- than oil-soluble. The duplex emulsions according to the invention may be used for systems in which the water-soluble tastant comprises one or more of edible acid, e.g. acetic acid, citric acid, lactic acid, malic acid, ascorbic acid, tartaric acid, succinic acid, and inorganic acids such as hydrochloric acid, phosphoric acid, sulphuric acid, sweet compounds such as sucrose, arabinose, ribose, xylose, glucose, galactose, mannose, fructose, lactose, maltose, raffinose, stachyose, trehalose, glycerol, erythritol arabitol, xylitol, sorbitol, mannitol, lactitol, malitol, and oligosaccharides such as corn syrups and other low molecular weight maltodextrins, and bitter compounds (e.g. peptides, amino acids, alkaloids, amides, thioureas, polyphenols) umami compounds (e.g. monosodium glutamate, disodium 5'-inosate, and disodium 5'-guanylate) salts such as sodium chloride, calcium chloride, potassium chloride.

In the duplex emulsions according to the invention various amounts may be used for water and oil, as long as the stability is not too much affected. Preferably, the internal aqueous phase (W1) is present at a phase volume between 10 and 60%, and more preferably between 20 and 50%. Likewise the amount of oil or fat is between 10 and 60%, more preferably between 15 and 40%.

In order to enhance emulsion stability it is preferred that the composition according to the invention comprises a surface active biopolymer in a concentration of 0.5 to 10% wt (based on the water phase). Examples of such surface active biopolymers are 1-octenyl-succinate hydrophobically modified starches (e.g. N-Creamer46, Purity Gum 539, Purity Gum 1773, Purity Gum 2000, HI CAP 100, Capsul N-Lok from National Starch) propylene glycol alginates, gum arabic, egg protein, milk proteins, soya protein, lupin protein, gelatine, acetylated pectin (e.g. sugar beet pectin), chitosan, gum ghatti, gum karaya, gum tragacanth and soyabean polysaccharides and cherry gum. Furthermore, the composition according to invention preferably comprises Admul Wol at a concentration of between 0.1 and 5% (wt based on the total composition). Such emulsifier may predominantly be found at the W1/O interface.

In order to maintain the stability it is preferred that all tastants are present in W1 and W2 in substantially similar or isotonic concentrations since this helps maintain the stability of the duplex emulsion during storage and consumption. Thermodynamic equilibrium of the low molecular weight solutes, particularly the tastants, may improve the stability of the duplex by reducing the osmotic and concentration gradients that could destabilise the emulsions during storage and consumption. However, in cases where some of the tastants (e.g. spices such as pepper, mustard, capsicum, turmeric, etc) may be present at low concentrations it may not be necessary to balance the concentrations in the W1 and W2 phases.

For the oil phase suitable components are edible fats and oils including hydrogenated or fractionated versions thereof. If to such oil phase a component capable of increasing the viscosity or gelation of the oil phase is added, then this may further help the taste suppressing effect, possibly by enhancing stability and/or slowing mass transfer of the taste component(s) upon or prior to consumption. Examples of such components (capable of increasing the viscosity or gellification of the oil phase) are: shea nut gum, ethyl cellulose, mono and di- glyceride, crystalline triglycerides, sterol, sterol esters, akogel, akomarin, calcium citrate, wax esters. When such thickeners of the oil phase are being applied, the tastant may also be the combination of sodium chloride, sucrose, and 10% acetic acid.

In order to aid physical stability it may be desirable to stabilise the inner W1 aqueous phase by addition of suitable biopolmer stabilisers capable of forming a gel. Examples of such components comprise one or more of iota carrageenan, kappa carrageenan, agar, agarose, Ca pectinate, Ca alginate, gelatin, milk protein, egg protein, soya protein, lupin protein, agarose konjac mannan. When such gelling biopolymers are being applied, the tastant may also comprise as sole tastants a combination of salt, sucrose and 10% acetic acid.

In order not to affect the texture and/or mouthfeel of the emulsion according to the invention it may be preferred that the W2 phase is not gelled.

Although the invention may work well if only the tastant that needs to be suppressed is present in isotonic concentrations, it may be preferred that all tastants are present in W1 and W2 in substantial similar or isotonic concentrations. This may e.g. help the physical stability of the duplex emulsions.

When compared to more or less standard duplex emulsions not having tastants present isotonically, the composition according to the above have larger oil droplets, e.g. such that 80%o of the droplets has a size in the range of a particle size of 20 to 200 micron, when the size is estimated by light microscopy.

The duplex emulsions according to the invention can be made using techniques as known in the art, although care has to be taken that the emulsions achieve such a stability that they are not completely destroyed upon eating, so as to exhibit the taste suppressing effect. To achieve this, it is possible to first make the primary W1/O emulsion using emulsification techniques that obtain a small droplet size, and then to carefully emulsify this in the outer water phase with more gentle treatment. In oderto further imporve stability the emulsifiers and stabilisers are preferably employed as mentioned hereinbefore. Also, in order to achieve optimal taste suppressing effect the binding biopolymer is an additional ingredient not reported to be used in the inner water phase of a duplex emulsion. In the present invention the W/O/W duplex emulsions are typically made by a two step procedure. The first step involves the preparation of a primary W/O emulsion. In the second step the primary emulsion is further emulsified in the outer aqueous phase. An internal w/o emulsifier is required to stabilise the primary W/O emulsion and preferably has a hydrophobic lipophillic balance (HLB) of less than or equal to 6. An example of such an emulsifier is polyglycerol polyricinoleic acid sold under the trade name Admul Wol. Other examples include saturated monoglycerides, polyglycerol esters of fatty acid, sugar esters of fatty acids, lecithin and propylene esters of fatty acids. The second stage involves the slow addition of the primary w/o emulsion to the outer W2 phase under mild mixing conditions to produce the W/O/W emulsion. An external O/W emulsifier is required for the second stage of the process and should preferably be a polymeric emulsifier with an HLB of greater than 8. Examples of these include proteins such as milk protein, egg protein, soya protein, lupin protein, gelatine and other surface active biopolymers such as hydrophobically modified starches (1-octenyl-succinate), propylene glycol alginates, gum arabic, chitosan and cherry gum, acetylated pectin (e.g. sugar beet pectin), gum ghatti, gum karaya, gum tragacanth and soyabean polysaccharides. EXAMPLES

Example 1 a-d, control: citric acid taste masking

For example 1a, the internal (W1) and external (W2) water phases were prepared by dissolving 40 grams of purity gum 539E (modified starch, ex National Starch, as OΛΛ 2 emulsifier), 3.65 grams citric acid monohydrate in 939.97 grams of deionised water with stirring. The pH was adjusted to 3.8 with 16.38 grams of 1M NaOH (buffer) and the mix was then pasteurised at 80°C for 10 minutes and cooled to 20°C (see table 1). The oil phase was prepared by solubilising 30 grams of Admul Wol 1408K (polyglycerol polyricinoleate from Quest) into 970g sunflower oil with gentle stirring. (Table 1). The first stage in the formation of the W/O /V emulsion involved the preparation of a primary W1/O emulsion comprised from water phase 1 and the oil phase. A fine W1/O emulsion with a drop size of less than approximately 10 μm was prepared by slowly adding 500g of water phase 1 to 300g of the oil phase under vigorous mixing conditions using a Silverson mixer. The second stage to form the w/o/w involved the addition of the primary W1/O emulsion to water phase 2. To make a W/O/W emulsion with a weight/weight ratio of 50/30/20, 800g of the primary W1/O emulsion from above was slowly added over a period of 15 minutes to 200g of water phase 2 and gently mixed using a overhead paddle stirrer. This resulted in the formation of a W1/O/W2 emulsion with a particle size of between 20 and 200μm depending on the degree of stirring and the viscosity of the emulsion, (visually estimated by light microscopy).

In a similar manner a range of duplex emulsions were prepared with W1/O/W2 ratios (weight/weight) of between 13/30/57 (example 1d) and 50/30/20 (example 1a), see table 2. As a control example a 30% O/W emulsion was prepared by emulsifying 300g of sunflower oil in 700g of water phase 2 using a Silverson mixer to produce a fine emulsion with a drop size of less than approximately 10 μm, (visually estimated by light microscopy).

Table 1

Table 2

The titratable acidity (TA) for each of the emulsions is shown in table 3. The TA is a measure of the emulsions' buffering capacity determined by titrating the emulsions from the start pH to pH 6. The results in Table 3 indicate that as more aqueous phase is incorporated into the oil phase the TA decreases because the acid in the internal water phase is not detectable. Panelling of these emulsions to ascertain their acidity was performed using a magnitude estimation methodology ('Sensory evaluation of food - Principles and practices', H.T. Lawless and H. Heymann, Aspen Publishers Inc., Gaithersburg, Maryland, USA, 1999). The results in Table 3 indicate that the perceived acidity decreases as the internal water phase increases. Table 3

Example 2 a-b, control: citric acid taste masking using propylene glycol alginate in place of Purity Gum 539E

For example 2a, the internal (W1) and external (W2) water phases were prepared by dissolving 12 grams of propylene glycol alginate and 3.65 grams citric acid monohydrate in 960.5 grams of deionised water with stirring. The pH was adjusted to 3.8 with 24 grams of 1M NaOH (buffer) and the mix was then pasteurised at 80°C for 10 minutes and cooled to 20°C (see table 4). The oil phase was prepared by solubilising 30 grams of Admul Wol 1408K into 970g sunflower oil with gentle stirring. The duplex emulsions was prepared in a similar manner to that mentioned in example 1 with W1/OΛ/V2 ratios (weight/weight) of between 35/30/35 (example 2a) and 50/30/20 (example 2b) as shown in table 5. As a control example a 30% O/W emulsion (control) was prepared by emulsifying 300 grams of sunflower oil in 700 grams of water phase 2 using a Silverson mixer to produce a fine emulsion.

Table 4

Table 5

The titratable acidity (TA) and perceived acidity for each of the emulsions is shown in table 6. The results in Table 6 indicate that as more aqueous phase is incorporated into the oil phase the TA decreases because the acid in the internal water phase is not detectable and causes a reduction in acid perception as the internal water phase volume increases.

Table 6

Example 3-a and control: citric acid taste masking in a mushroom sauce.

For example 3a, the internal (W1) and external (W2) water phases were prepared by dissolving 40 grams of purity gum 539E (modified starch, ex National Starch, as O/W2 emulsifier), 4 grams citric acid monohydrate, 17 grams of Blanchaurd freeze dried mushroom extract, 5 grams of mushroom flavour (ex Dragoco) and 0.5 grams black pepper in 933.5 grams of deionised water with stirring. The pH was adjusted to 3.8 with 7 grams of 4M NaOH (buffer) and the mix was then pasteurised at 80°C for 10 minutes and cooled to 20°C (see table 7). The oil phase was prepared by solubilising 16.6 grams of Admul Wol 1408K (polyglycerol polyricinoleate from Quest) into 983.4 grams sunflower oil with gentle stirring. The first stage in the formation of the W/O/W emulsion involved the preparation of a primary W1/O emulsion comprised from water phase 1 and the oil phase. A fine W1/O emulsion by slowly adding 400 grams of water phase 1 to 240 grams of the oil phase under vigorous mixing conditions using a Silverson mixer. The second stage to form the WOΛ/V involved the addition of the primary W1/0 emulsion to water phase 2. To make the W/O/W emulsion 640 grams of the primary W1/O emulsion from above was slowly added over a period of 15 minutes to 360 grams of water phase 2 and gently mixed using an overhead paddle stirrer. As control example a 24% o/w emulsion was prepared by emulsifying 240 grams of sunflower oil in 760 grams of water phase 2 using a Silverson mixer to produce a fine emulsion. The titratable acidity (TA) and perceived acidity scores for each of the emulsions are shown in table 8.

Table 7

Table 8

Example 4 Storage trial of duplex emulsions containing citric acid. A 50/30/20 duplex emulsion (Table 9) was prepared in a similar manner to that described in example 1 and were stored at 25 °C and 5 °C. The titratable acidity of the emulsions were measured during storage from which it was possible to calculate the external phase volume. This was used as an indicator of stability because coalescence of the inner W1 phase with the outer W2 phase would result in an increase in the measured titratable acidity. The results in figure 1 indicate that a small amount of the internal W1 aqueous phase coalesces with the outer W2 phase and the effect is more pronounced at 25 °C. The droplet size distribution of the emulsion is measured by small angle laser light scattering using a Malvern Mastersizer. The average droplet size (d₄₃) of the fresh emulsion is the parameter of interest providing a measure of the coalescence of the duplex droplets (Figure 2).

Table 9

Claims

1. Edible composition comprising a W1/O/W2 duplex emulsion wherein both water phases W1 (dispersed water phase) and W2 (continuous water phase) comprise at least one water-soluble tastant in both of the water phases and wherein said waterphases W1 and W2 are substantially isotonic for said tastant and wherein the composition does not comprise as sole tastants a combination of salt, sucrose and 10%) acetic acid.

2. Composition according to claim 1, wherein the water-soluble tastant comprises one or more compound capable of expressing a sweet, salty, sour, bitter or umami taste.

3. Composition according to claim 1-2, wherein the tastant comprises one or more of citric acid, lactic acid, malic acid, ascorbic acid, tartaric acid, succinic acid, hydrochloric acid, phosphoric acid, sulphuric acid, arabinose, ribose, xylose, glucose, galactose, mannose, fructose, lactose, maltose, raffinose, stachyose, trehalose, glycerol, erythritol arabitol, xylitol, sorbitol, mannitol, lactitol, malitol, corn syrup, low molecular weight maltodextrins, peptides, amino acids, alkaloids, amides, thioureas, polyphenols, monosodium glutamate, disodium 5'-inosate, and disodium 5'-guanylate, calcium chloride, potassium chloride.

4. Composition according to claim 1-3, wherein the internal aqueous phase (w1) is at a phase volume between 10 and 60%, and more preferably between 20 and 50%.

5. Composition according to claim 1-4, wherein the amount of oil or fat is between 10 and 60%), more preferably between 15 and 40%.

6. Composition according to claim 1-5, wherein at least 50% of the duplex droplets remain intact in the mouth upon consumption.

7. Composition according to claim 1-6, wherein the composition comprises a surface active biopolymer in a concentration of between 0.5 and 10.0% wt on the water phase.

8. Composition according to claim 7 in which the surface active biopolymer comprise one or more of hydrophobically 1-octenyl-succinate modified starches, propylene glycol alginates, gum arabic, egg protein, milk proteins, soya protein, lupin protein, gelatine, acetylated pectin, chitosan, gum ghatti, gum karaya, gum tragacanth and soyabean polysaccharides, cherry gum in a concentration of between 0.5 and 10.0% wt on the water phase.

9. Composition according to claim 1-8, wherein the composition further comprises Admul WOL at a concentration of between 0.1 and 5% on the total composition.

10. Composition according to claim 1-9, wherein the waterphase W1 further comprises a biopolymer capable of forming a gel.

11. Composition according to claim 10, wherein the gellable biopolymer comprises one or more of iota carrageenan, kappa carrageenan, agar, agarose, Ca-pectinate, Ca- alginate, gelatin, milk protein, egg protein, soya protein, lupin protein, agarose, konjac mannan.

12. Composition according to claim 10-11, wherein the biopolymer is a charged biopolymer.

13. Composition according to claim 12, wherein the charged biopolymer comprises alginates, propylene glycol alginates, pectinates, gellan, and adipate - and succinate modified starches.

14. Composition acording to claim 1-13, wherein the W2 phase is not gelled.

15. Composition according to claim 1-14, wherein 80% of the the oil droplets has a particle size of 20-200 micron diameter.

16. Composition according to claim 1-15, wherein the oil phase comprises a component capable of increasing the viscosity or gellification of the oil phase.

17. Edible composition comprising a W1/O/W2 duplex emulsion wherein both water phases W1 (dispersed water phase) and W2 (continuous water phase) comprise at least one water-soluble tastant in both of the water-soluble phases and wherein said tastant is capable of expressing a sweet, salty, sour, bitter or umami taste and wherein said waterphases W1 and W2 are substantially isotonic for said tastant, and wherein the oil phase comprises a component capable of increasing the viscosity or gellification of the oil phase.

18. Composition according to claim 17, wherein the tastant comprises one or more of acetic acid, citric acid, lactic acid, malic acid, ascorbic acid, tartaric acid, succinic acid, hydrochloric acid, phosphoric acid, sulphuric acid, arabinose, ribose, xylose, glucose, galactose, mannose, fructose, lactose, sucrose, maltose, raffinose, stachyose, trehalose, glycerol, erythritol arabitol, xylitol, sorbitol, mannitol, lactitol, malitol, corn syrup, low molecular weight maltodextrins, peptides, amino acids, alkaloids, amides, thioureas, polyphenols, monosodium glutamate, disodium 5'-inosate, and disodium 5'- guanylate, sodium chloride, calcium chloride, potassium chloride.

19. Composition according to claim 17-18, wherein the component capable of increasing the viscosity or gellification of the oil phase comprises shea nut gum, ethyl cellulose, mono and di glyceride, crystalline triglycerides, sterol, sterol esters, akogel, akomarin, calcium citrate, wax esters.