Nanoemulsions for beverages

Abstract

Nanoemulsions for non-alcoholic beverages. Nanoemulsions contain multiple oil droplets with a z-average droplet size of less than 100 nm, an aqueous phase and a surfactant system. The oil droplets contain hydrophobic compounds and are dispersed in an aqueous phase containing water and a co-solvent, such as glycerol. The surfactant system includes sucrose esters and lecithins, such as sucrose monopalmitate and highly hydrolyzed sunflower lecithin. Dilutable nanoemulsions are useful for flavoring non-alcoholic versions of distilled spirit beverages such as gin, whose flavor ingredients consist of hydrophobic compounds and are typically water insoluble.

Description

[Technical field]

[0001] The present invention relates to beverage nanoemulsions, particularly nanoemulsions with stability at low pH, for the purpose of carrying hydrophobic compounds such as flavorings in non-alcoholic or low-alcohol beverage products. [Background technology]

[0002] The characteristic botanical aromas of potable spirits such as gin made by traditional distillation methods are provided by classes of compounds that are poorly water soluble (e.g., terpenes in the case of gin). Solubility is not an issue in full strength gin because the concentration of ethanol (e.g., 40% by volume) is sufficient to solubilize these compounds.

[0003] However, if it is desired to mimic the taste and aroma of distilled spirits in a non-alcoholic version of the product, such aroma compounds, being hydrophobic, cannot simply be added as direct ingredients due to their insolubility as mentioned above; phase separation would occur.

[0004] One solution to overcome the solubility limit of such aroma compounds in water is to disperse the aroma compounds in the form of surfactant-stabilized droplets (emulsions). However, known formulation techniques for emulsions do not produce satisfactory results because the resulting liquid is cloudy. Since consumers of spirits expect a clear product, high levels of turbidity are unacceptable.

[0005] It is worth noting that microemulsions, as will be appreciated by those skilled in the art, are distinct from nanoemulsions: typically, nanoemulsions are kinetic / metastable but thermodynamically unstable, whereas microemulsions are thermodynamically stable and form without energy input.

[0006] WO2016 / 064828 describes a translucent flavor nanoemulsion containing a flavor oil phase, an aqueous phase, and a surfactant system with first and second lecithins. The resulting formulation has about 30% more lecithin than the present invention described below, which is responsible for the slight yellowish color of the final beverage.

[0007] The majority of non-alcoholic products are made with a pH between 2.5 and 7. It is generally understood in the art that a "low pH" is anything below 4. Indeed, in the beverage industry, anything below 4 is considered a "low pH." Summary of the Invention

[0008] The present invention aims to provide a system for beverages containing hydrophobic compounds, which may consist of a flavor system, with a low level of turbidity, in other words a low pH and transparent nanoemulsion, or at least provide a useful option for formulating non-alcoholic or low-alcoholic beverage products. Nanoemulsions in this context require optical clarity, stability and are dilutable from concentrate for use in consumable beverages.

[0009] In a first aspect, the present invention provides a pH-stable, transparent nanoemulsion for beverages according to claim 1. The present invention essentially relates to a low pH-stable nanoemulsion comprising a plurality of oil droplets, an aqueous phase, and a surfactant system, each of the oil droplets having a z-average droplet size of less than 100 nm (i.e., z-average is a value derived from the intensity size distribution measured by dynamic light scattering, where "size" refers to the maximum lateral width) contains a hydrophobic compound (e.g., flavor) and is dispersed in an aqueous phase, the aqueous phase containing water, preferably a co-solvent, and the surfactant system includes sucrose esters and lecithin. Alternatively, the present invention may be described as a low pH-stable, transparent nanoemulsion for beverages, comprising a mixture of surfactants consisting of at least one hydrophobic compound, a first surfactant (preferably, e.g., sucrose esters) with a hydrophilic lipophilic balance (HLB) value greater than 15, and a second surfactant (e.g., lecithin) with an HLB value between 4 and 8, and an aqueous phase containing a co-solvent. The HLB (hydrophile / lipophile / balance) number of a surfactant is an empirical measure of its relative hydrophobicity.

[0010] In a preferred form, the nanoemulsions are kinetically stabilized and can be diluted without affecting stability due to droplet size changes or aggregation during storage. The ability to dilute is useful as concentrates are prepared for subsequent dilution into consumable beverages with desirable taste characteristics.

[0011] In the context of the present invention, the stability of "low pH stable" refers to the fact that the ingredients do not go out of solution or that the droplet size and transparency, etc. do not change. If the nanoemulsion is not low pH stable, these negative properties are observed relatively quickly, for example within a day to a few weeks, in a low pH environment. Stability at low pH should not be confused with the overall lifespan of the shell, which can be a year or more for products of this nature.

[0012] The claimed nanoemulsion refers to both the concentrated preparation and its diluted drinkable form (i.e., either may be considered as a nanoemulsion). The nanoemulsions according to the invention remain stable upon dilution, i.e., there is no change in droplet size, and such droplet size can be measured to confirm stability. The oil concentration in the final ready-to-consume liquid ranges from approximately 0.01 to 0.5 g / L, preferably less than 0.25 g / L. The droplet size in such ranges in both concentrated liquid and diluted / drinkable form is measurable. For the avoidance of doubt, liquid beverages are claimed herein.

[0013] In one form, the fragrance (i.e., hydrophobic compound) may include a terpene or mixture of terpenes (e.g., pinene, myrcene, and limonene), or any other hydrophobic material.

[0014] Classification of hydrophobic compounds can be defined by their logP value.Specifically, there are many examples of hydrophobic perfume compounds that are of limited solubility, and generally, hydrophobicity is usually measured as Log Kow, also known as LogP, which is the partition coefficient of a molecule between an aqueous phase and a lipophilic phase, usually octanol and water.LogP is often used to indicate the solubility characteristics of hydrophobic compounds, since it is inversely related to solubility.Generally, compounds that are considered hydrophobic with relatively low solubility in water have a LogP value of greater than 2.Therefore, in the present invention, hydrophobic compounds have a logP value of 2 or greater.

[0015] In particular aspects and combinations of the present invention, The weight ratio of the surfactant system to the hydrophobic compound may be from 0.3:1 to 1:1. · The concentration of hydrophobic compounds ranges from 10 to 40 g / L. The first surfactant (eg, a sucrose ester) can be sucrose monolaurate, sucrose monopalmitate, or a combination thereof. The second surfactant (eg lecithin) may be (eg highly hydrolyzed) sunflower lecithin. The weight ratio of the first surfactant to the second surfactant (sucrose ester to lecithin) in the surfactant system can be from 70:30 to 20:80. The co-solvent may be a polyol (e.g., glycerol, propylene glycol or a mixture of both or other equivalents). The concentration of the polyol may be 1-500 g / L, e.g., 100-400 g / L propylene glycol. The pH of the nanoemulsion must be in the range of 3.0-8.0, preferably 3.4-7. The average (or more specifically, z-average) droplet size of the nanoemulsion must be less than or equal to 100 nm, preferably less than or equal to 70 nm. A liquid beverage should preferably have a turbidity of 5 NTU or less to be considered clear. However, some variation (including higher NTU) may be possible, especially if the liquid has some color. "Clear", as disclosed herein, encompasses beverages that are substantially clear with no color, such as gin, and beverages with some color / tint, such as whiskey. The beverages in which the nanoemulsions are found may contain alcohol. Preferably, the beverage products have a relatively low alcohol content, e.g., up to 20%, but in practice perhaps 15% ABV or less, as compared to full strength spirits.

[0016] A further aspect of the invention relates to a method for preparing a nanoemulsion, e.g. as described in claim 1, comprising the following steps: a) providing an aqueous phase containing a sucrose ester and a co-solvent; b) providing an oil phase containing a hydrophobic compound (e.g., a flavoring agent) and lecithin; c) emulsifying the oil phase in the water phase, thereby obtaining a nanoemulsion; A method is provided, comprising:

[0017] This aspect of the invention generally relates to a method for preparing a nanoemulsion for carrying a hydrophobic compound for use in a beverage, the method comprising the steps of: Providing at least one hydrophobic compound, which may be aromatic; Providing a first surfactant that is hydrophilic and a second surfactant that is lipophilic and acts as a stabilizer for at least one hydrophobic compound; mixing at least one hydrophobic compound, a first surfactant and a second surfactant to form a nanoemulsion; The method can be considered to include the steps of:

[0018] The first surfactant has an HLB value higher than 15 and the second surfactant has an HLB value between 5 and 8. The surfactants may be combined in a ratio between 20:80 and 70:30, more specifically between 60:40 and 40:60.

[0019] As mentioned above, the hydrophobic compound may include a terpene or a mixture of terpenes, such as pinene, myrcene, and limonene. The first surfactant may be a sucrose ester, such as sucrose monopalmitate (SPM), and the second surfactant may be a lecithin, such as sunflower lecithin (SL).

[0020] Advantageously the surfactant to oil ratio should be kept low, for example 1:3, but such ratio can be up to 1:1, for example 1:2.

[0021] In concentrated form, the product contains per liter of total volume: 200g to 980g of water, Hydrophobic compounds in amounts up to 30 g / L, and A combination of surfactants in an amount of up to 10 g / L; Propylene glycol in an amount of 100-400 g / L; Glycerol in amounts of 0-600 g / L; may include.

[0022] In one form of the process, the mixing is carried out in a high shear mixer. Propylene glycol may be added as a co-solvent to the aqueous solution prior to mixing, for example in an amount of 100-500 g / L. The mixture may be homogenized at up to 400 bar.

[0023] In yet a further aspect, the invention encompasses beverages containing carriers of hydrophobic compounds, ie, nanoemulsions.

[0024] The carrier of the hydrophobic compound may be diluted from a ready-to-use concentrate, i.e., to obtain a concentrate for further effective dilution of the at least one hydrophobic compound to 0.05-0.15 g / L.

[0025] To maintain the transparency of the final liquid, the droplets must be small enough so as not to significantly increase the scattering of light. As a generalized rule, droplets with a z-average size of less than 100 nm do not increase the turbidity of the final liquid. A turbidity of less than 5 NTU is considered the practical threshold to ensure transparency. [Brief description of the drawings]

[0026] [Figure 1A] FIG. 1 shows the change in droplet size as a function of propylene glycol concentration and surfactant ratio for a mixture of hydrophobic compounds with LogP 3.16. [Figure 1B] FIG. 1 shows the change in droplet size as a function of propylene glycol concentration and surfactant ratio for a mixture of hydrophobic compounds with LogP 4.5. [Diagram 2] FIG. 1 illustrates an exemplary process for producing a nanoemulsion according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The following description presents exemplary embodiments and, together with the drawings, serves to explain the principles of the present invention.However, the scope of the present invention is not intended to be limited to the exact details of the embodiments, since variations are obvious to those skilled in the art and are also considered to be covered by the description.The terms for the formulation components used in this specification should be given a broad interpretation to include compounds / components with equivalent functions and characteristics.In some cases, substitutions may be suggested, but are not intended to be exhaustive.

[0028] Descriptive terms should also be given a broad interpretation, for example, the term "comprising" as used herein means "consisting at least in part of," such that each description herein containing the term "comprising" should be interpreted such that features other than those preceded by the term may also be present. Related terms such as "comprise" and "comprises" should be interpreted in the same manner.

[0029] As an overview of the present invention, concentrated nanoemulsions (e.g., 10 g / L of hydrophobic compound, but could be higher, such as 30-50 g / L) were produced using a high-pressure homogenizer at 400 bar. Two different types of surfactants, firstly hydrophilic (e.g., sucrose monopalmitate, SMP) and secondly lipophilic (e.g., highly hydrolyzed lecithin), were selected in a specific ratio that resulted in stability as well as small droplet size.

[0030] FIG. 1A shows the variation in droplet size D90 (i.e., derived from the volume size distribution and represents the largest particle size below which 90% of the sample volume resides). D90 was chosen (instead of z-average) to test and explore the optimum range. However, within the optimum range, all emulsions have a Z-average below 100. Also, Z-average is the most convenient to measure the droplet size of the final product.

[0031] In particular, Figures 1A and 1B illustrate 3D surface plots of droplet size as a function of surfactant to propylene glycol concentration ratio, e.g., the change in droplet size as a function of SMP / lecithin ratio and propylene glycol. Figure 1A shows the results of an emulsion concentrate of a mixture of hydrophobic fragrance compounds having a weighted average logP of 3.16 at pH 7, and Figure 1B shows the results of an emulsion concentrate of a mixture of fragrance compounds having a logP of 4.35 at pH 7.

[0032] It can be observed that the emulsion containing the perfume with a logP of 3.16 shows a minimum in droplet size for SMP / lecithin ratios between about 30:70 and 60:40, and propylene glycol concentrations between 0 and 400 g / L. The minimum droplet size is obtained at a surfactant ratio of 55:45 and a propylene glycol concentration of 250 g / L.

[0033] The fragrance-containing emulsion concentrate with a logP of 4.35 according to Figure 1B shows the smallest droplet size for SMP / lecithin ratios between 50:50 and 30:70, and propylene glycol concentrations between 250 and 450 g / L. The smallest droplet size is obtained at a surfactant ratio of 35:65 and a propylene glycol concentration of 400 g / L.

[0034] As further background for understanding the nature of the present invention, test results are outlined below utilizing three different fragrance systems: Sucrose monopalmitate (SPM) and sunflower lecithin (SL) were selected as surfactants.

[0035] Samples were prepared by dispersing SL in the oil phase at 60° C., e.g., by the process of FIG. 2, while the SMP was hydrated in the water phase under constant shear at 85° C. for 2 hours. The two phases were then mixed with propylene glycol using a high shear mixer for 2 minutes, followed by homogenization at 400 bar (3 times). EXAMPLES

[0036] TIFF0007656778000001.tif53170 EXAMPLES

[0037] TIFF0007656778000002.tif53170 EXAMPLES

[0038] TIFF0007656778000003.tif52170 EXAMPLES

[0039] TIFF0007656778000004.tif53170

[0040] Such concentrates did not show any signs of instability after storage for 3 months at 20° C. In practice, the concentrates are then diluted 100 times to obtain the concentration of approximately 0.1 g / L required for the final product. The turbidity of the final liquid is less than 5 NTU. Table 1 below shows the turbidity of a pH 3.4 solution containing 0.1 g / L oil of each nanoemulsion formulation.

[0041] [Table 1] Table 1

[0042] Table 2 below shows the stability over time after dilution. Samples were prepared by diluting the nanoemulsion (10 g / L oil; 30 / 70 sucrose monoester / lecithin ratio) into water containing 0.33 g / L trisodium citrate and the amount of citric acid needed to lower the pH to 3.5. Stability at low pH is particularly important as the majority of liquids in this category of beverages (eg non-alcoholic gin) have a pH around that tested, ie 3.5.

[0043] [Table 2] Table 2

[0044] It can be observed that both the droplet size and the turbidity decrease over time. The present invention is therefore particularly suitable for use as a dilutable formulation that does not lose its useful properties over time.

[0045] In conclusion, we have successfully developed a pH-stable nanoemulsion concentrate (approximately 1% oil) using a mixture of sucrose monopalmitate and sunflower lecithin. In summary, a nanoemulsion contains multiple oil droplets, e.g., less than 70 nm in diameter, an aqueous phase, and a surfactant system. The oil droplets contain a hydrophobic compound (flavoring) and are dispersed in an aqueous phase containing water and a cosolvent, e.g., glycerol. The surfactant system contains sucrose esters and lecithin, e.g., sucrose monopalmitate and highly hydrolyzed sunflower lecithin. Nanoemulsions are useful for flavoring non-alcoholic versions of distilled beverages such as gin, whose flavoring ingredients are typically water-insoluble.

Claims

1. A liquid beverage that does not contain alcohol or has an alcohol concentration of 15% ABV or less in the liquid beverage, A plurality of oil droplets having a z-average droplet size of less than 100 nm; an aqueous phase consisting of water and a co-solvent consisting of propylene glycol and / or glycerol; and A two surfactant system comprising a first surfactant having an HLB value higher than 15 and a second surfactant with an HLB value between 4 and 8; The nanoemulsion for beverages has a low pH and is stable, each of said oil droplets comprises a hydrophobic perfume compound having a LogP value of 2 or greater dispersed in said aqueous phase; the weight ratio of said surfactant system to said hydrophobic perfume compound is between 0.3:1 and 1:1; the first surfactant is selected from the group consisting of sucrose monolaurate or sucrose monopalmitate; the second surfactant is highly hydrolyzed sunflower lecithin; liquid drinks.

2. 10. The liquid beverage of claim 1, which is dilutable with water in a ratio of up to 3:

100.

3. 2. The liquid beverage of claim 1, wherein the hydrophobic flavor compound is a terpene or a mixture of terpenes selected from pinene, myrcene and limonene.

4. 2. The liquid beverage of claim 1, wherein the weight ratio of the first surfactant to the second surfactant is between 30:70 and 80:

20.

5. 2. The liquid beverage of claim 1, wherein the co-solvent is a polyol at a concentration of 1 to 800 g / L.

6. 2. The liquid beverage of claim 1, wherein the z-average droplet size is less than 70 nm.

7. 10. The liquid beverage of claim 1 having a turbidity of 5 NTU or less.

8. The liquid beverage according to claim 7, wherein the concentration of the oil droplets is 0.01 to 0.5 g / L.

9. 13. A method for preparing a nanoemulsion for a liquid beverage according to claim 1, comprising the steps of: Providing an aqueous phase containing water, sucrose monolaurate or sucrose monopalmitate, and a co-solvent consisting of propylene glycol and / or glycerol; providing an oil phase containing a hydrophobic flavor compound having a LogP value of 2 or more and highly hydrolyzed sunflower lecithin; emulsifying said oil phase in said aqueous phase, thereby obtaining said nanoemulsion consisting of oil droplets with a z-average droplet size of less than 100 nm; A method comprising:

10. 10. The method of claim 9, wherein the pH of the nanoemulsion ranges from 3.0 to 8.

0.

11. 10. The method of claim 9, wherein the hydrophobic fragrance compound is a terpene or a mixture of terpenes including pinene, myrcene and limonene.

12. 10. The method of claim 9, wherein the weight ratio of sucrose monolaurate or a mixture of sucrose monopalmitate and lecithin to said hydrophobic flavor compound is between 0.3:1 and 1:

1.

13. 10. The method of claim 9, wherein the co-solvent is glycerol added in an amount of 1 to 700 g / L.

14. 10. The method of claim 9, wherein the mixing is carried out in a high shear mixer.

15. 10. The method according to claim 9, wherein the homogenization is carried out in a high pressure homogenizer at up to 500 bar.

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