Frozen desserts

Abstract

The present invention provides a water-in-oil emulsion for preparing frozen desserts, the emulsion comprising an aqueous phase and an oil phase in a weight ratio of 94:6 to 70:30, wherein: the oil phase comprises at least an edible oil and an emulsifier, the average HLB of the emulsifier is 0.1-5; the aqueous phase comprises at least water and one or more freezing point depressants; the emulsion comprises at least (W×A) wt% of the emulsion by weight, wherein: W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion; and A is 0.0001; the emulsion comprises at most (O×0.2) wt% of the emulsion by weight, wherein: O is the proportion of the oil phase in the emulsion, expressed as a weight percentage of the total emulsion; the emulsion comprises one or more freezing point depressants at 4-40 wt% of the emulsion by weight; and the temperature when the edible oil contains 25 wt% of solid fat by weight of the edible oil is lower than the temperature when the aqueous phase contains 25 wt% of ice by weight of the aqueous phase.

Description

[0001] Technical field of the invention

[0002] The present invention relates to a water-in-oil emulsion, in particular a water-in-oil emulsion suitable for producing frozen desserts. The present invention also relates to a frozen dessert made from the water-in-oil emulsion, and a method for preparing the resulting frozen dessert. Background of the Invention

[0004] Typical ice cream consists of about 30% ice by volume, 50% air by volume, 5% fat by volume, and 15% matrix (sugar solution) by volume. Therefore, it contains all three states of matter: solid ice and fat, liquid sugar solution, and gas. The fat is contained in a fat-in-water (or "oil-in-water") emulsion formed as described below. Solids and gases are present in the continuous liquid phase, the matrix, in the form of small particles, namely ice crystals, fat droplets, and gas bubbles. Colloidal dispersions consist of small particles of one phase (solid, liquid, or gas) in another continuous phase. The particle size range can be from nanometers to tens of micrometers. The volume of a colloidal dispersion has a very large surface area. Therefore, the surface properties of the phases have a great influence on the overall properties. Typical ice cream is an emulsion (fat droplets), a sol (ice crystals), and a foam (air) at the same time. Ice cream production involves the following steps: mix preparation; pasteurization and homogenization; aging; freezing; and hardening.

[0005] The first step in producing ice cream is the preparation of the mix. The mixing process is designed to mix, disperse, hydrate and dissolve the ingredients together in the shortest time with optimal energy usage. After all ingredients are added, the mix should be homogenized at about 65°C or higher. The shear forces generated by stirring produce a crude oil-in-water emulsion with larger fat droplets (about 10 μm in diameter).

[0006] Next, the mixture is pasteurized to reduce the number of viable microorganisms to a level safe for human consumption, and homogenized to break down the fat particles into many small droplets. A large amount of energy is required to heat the mixture to the pasteurization temperature. In order to maximize energy efficiency, heating can be performed in two stages. In the first stage, the mixture is taken from the mixing tank and passed through a plate heat exchanger. This is designed to ensure good heat transfer and easy cleaning, which consists of two separate flow systems flowing through staggered plates. The first flow system contains the incoming mixture, while the second flow system contains the hot mixture that has been pasteurized and homogenized. Therefore, the incoming mixture is heated, and the pasteurized and homogenized mixture undergoes a first stage of cooling, which is necessary before the next step in the production process. In the second heating step, the mixture is further heated with hot water in another part of the plate heat exchanger. At the end of this stage, the mixture must be hot enough to ensure that the pasteurization temperature is reached after homogenization. The temperature should not exceed about 81°C to prevent the denaturation of milk proteins and avoid the introduction of off-flavors.

[0007] In the homogenizer, the hot mixture (>70°C) passes through small valves under high pressure (usually up to about 150 atmospheres). Large fat droplets are elongated and broken into a fine emulsion of smaller droplets (about 1-4 μm in diameter), greatly increasing the surface area of ​​the fat. Sometimes a second homogenization step is used, which uses a lower pressure (about 35 atmospheres) to reduce the aggregation of small fat droplets after the first stage.

[0008] After homogenization, milk proteins tend to adsorb to the surface of fat droplets. The proteins adsorb mostly on the water side of the fat / matrix interface, with the hydrophobic part at the interface. Free casein, casein micelles, and whey have different surface activities, so they adsorb differently on fat droplets; for example, casein adsorbs more than whey. Proteins stabilize oil-in-water emulsions very well against coalescence because they provide a strong, thick film around the fat droplets. Interactions between proteins outside the droplets make it more difficult for the droplets to come into close contact.

[0009] Pasteurization can also be carried out in a holding tube, which is a length of tube from the outlet of the homogenizer, the length and diameter of which are selected to ensure that the mixture is held at the pasteurization temperature for the required time. A typical pasteurization schedule is 31 seconds at a temperature of 80.5°C.

[0010] After pasteurization, the mixture is cooled and then aged, during which the emulsifiers adsorb to the surface of the fat droplets, replacing some of the milk proteins. As the mixture cools, the monoglycerides / diglycerides begin to crystallize, making them more hydrophobic, so they adsorb more strongly to the fat droplets. Emulsifiers have their fatty acid chains in the fat phase and polar parts on the surface. Emulsifiers replace some proteins to produce weaker films. The film is strong enough to stabilize the emulsion under static conditions in the aging tank, but makes the emulsion unstable under shear in the freezer. Afterwards, the fat inside the droplets begins to crystallize. Since nucleation must occur inside each individual droplet, crystallization is slow. Crystallized monoglycerides / diglycerides and high melting point triglycerides promote fat crystallization by acting as nucleation points. Fat crystals can protrude from the surface of the droplets. Aging must be long enough to allow crystallization to occur and for the emulsifiers to replace some proteins, because both processes are important precursors in the next stage of ice cream production. Without them, it is difficult to incorporate and stabilize bubbles when the mixture is frozen in an ice cream freezer.

[0011] Freezing is usually carried out using a scraped surface heat exchanger designed to remove heat from the viscous liquid of the ice cream mix. An ice cream freezer consists of a cylindrical barrel that is usually 0.2m in diameter and 1m in length, but there are many sizes of freezers designed for different production rates. A refrigerant flows through the jacket and cools the outside of the barrel as it evaporates. Inside the barrel is a rotating stainless steel mixer driven by a motor. The mixer is equipped with a scraper that fits very tightly inside the barrel. The mixer has two functions: to subject the mixture to high shear, and to scrape off the layer of ice crystals that form on the very cold barrel wall. There are two types of mixers, open and closed. An open mixer has an open cage that supports the scraper, which contains a passively rotating beater. The mixer occupies 20%-30% of the barrel volume. With the same outlet temperature and output, an open mixer has lower shear and longer residence time than a closed mixer. An open mixer is commonly used in ice cream production. A longer residence time helps to achieve good aeration.

[0012] The ice cream mix at about +4°C is pumped from the aging tank into a barrel, where it is aerated and frozen before being pumped out of the other end. Air is injected into the barrel. Initially, the air forms large bubbles. In order to obtain high-quality ice cream, it is necessary to produce (and maintain) a dispersion of small bubbles. The whipping of the mixer shears the large bubbles and breaks them into many smaller bubbles: the greater the shear stress applied, the smaller the bubbles. Long residence times also produce small bubbles. It is easier to whip the air into a foam consisting of a large volume proportion of liquid and a small volume proportion of air than vice versa. The high pressure inside the barrel reduces the volume of air that has been introduced and therefore makes further aeration easier.

[0013] Shear also causes some of the fat droplets to collide with each other and coalesce. The mixed protein-emulsifier layer is designed to make the emulsion stable under static conditions, but unstable under shear. Even though mono / diglycerides and lecithin are called emulsifiers, their function in ice cream is to de-emulsify the fat. Needle-like fat crystals protruding from the surface of the droplets help this process. They can pierce the mixed protein-emulsifier layer on another droplet, causing the droplets to coalesce. The choice of fat type and aging process ensures that the fat in the ice cream mix is ​​partly solid and partly liquid so that the droplets can partially coalesce, i.e. they form clusters but retain some of their individual properties. Partially coalesced fat droplets are also called de-emulsified or destabilized fats. Milk fat, coconut oil, palm oil and palm kernel oil are conventionally used because these substances are mostly solid at the temperatures at which they are frozen and aerated in ice cream freezers, and therefore they undergo partial coalescence.

[0014] The mixture is frozen while being aerated. Heat must be removed from the mixture to cool it (sensible heat) and to freeze the water into ice (latent heat). About five times more heat must be removed to freeze the water than to cool the mixture. As the mixture passes through the barrel, its temperature decreases and its ice content increases. This causes the viscosity of the mixture to increase: the viscosity of a sugar solution increases as the temperature decreases, and the viscosity of a suspension increases as the volume fraction of ice increases. The function of the ice content (i.e., the mass of ice as a percentage of the total mass) of a typical ice cream as a function of temperature (e.g., 0 to -20°C) is called the ice curve. The ice content of a typical recipe is about 30% when it leaves the factory freezer at -5°C, and about 55% at a typical storage temperature of -18°C.

[0015] It can therefore be understood that when ice cream leaves a factory freezer at about -5°C, its ice content is only about half of that at a typical serving temperature of -18°C, and is therefore very soft. As mentioned above, the microstructure of dispersed ice crystals and bubbles is thermodynamically unstable, i.e. the system tends towards a state of low dispersed phase. If the ice cream is simply stored at the outlet temperature of the factory freezer, it will deteriorate very quickly. The ice crystals and bubbles will coarsen: their average size will increase and their total number will decrease. Since it is not possible to thermodynamically stabilize the microstructure, it can instead be kinetically trapped, i.e. by slowing down the rate at which coarsening occurs so that no significant degradation of the microstructure occurs. For these reasons, the temperature of the ice cream is reduced as quickly as possible after leaving the factory freezer. This is called hardening. Ice cream is usually hardened in a tunnel hardening chamber, which is a closed chamber through which the ice cream from the factory freezer passes on a conveyor belt. Inside it, cold air (usually -30 to -45°C) is blown over the ice cream. The lower the air temperature and the faster the air movement, the faster the heat is removed from the ice cream.

[0016] The ice cream is then stored in cold storage, typically at about -25°C, before being distributed through the cold chain at about the same temperature and then stored in a freezer at about -18°C at the point of sale.

[0017] Therefore, it is clear that the production of standard ice cream containing a fat-in-water emulsion requires very careful control of operating parameters to obtain the desired emulsion. It also requires a lot of energy during production to obtain the microstructure, and during product storage, a lot of energy is also required so that the organoleptic properties generated by the microstructure can be maintained in the supply chain for central storage, distribution to further logistics points, subsequent transportation to sales points and then consumption after purchase or further storage at home before consumption. It is well known that the supply chain quality from factory to consumption point varies greatly, and when the temperature falls outside the optimal window, the product is damaged. For example, if the temperature is too low, in addition to the wasteful energy consumption, the product is also unacceptably hard and the organoleptic properties are damaged. On the contrary, if the temperature is too high, the product quality is damaged due to the obvious reasons of ice melting and microstructure loss.

[0018] The present invention seeks to provide frozen desserts with a wider temperature stability window. The present invention also seeks to provide such frozen desserts, which can be frozen at higher temperatures, thus requiring less energy to cool and freeze, and thus can also be distributed in the supply chain at a higher temperature than the current standard, which again reduces energy consumption. The present invention also aims to provide a non-frozen emulsion product, which can be provided and stored at ambient temperature, or provided and stored at a refrigerator temperature of about 4°C, and can be frozen later in the supply chain or at home after further mixing, thus greatly reducing the cold zone link of the supply chain, and thus reducing energy consumption.

[0019] The prior art has attempted to address these challenges in various ways, such as by using high levels of stabilizers in standard oil-in-water based formulations, complex emulsifier systems and other approaches.

[0020] However, there remains a need for improved frozen confections which address the above challenges and which can be produced simply and cost-effectively.

[0021] The inventors have surprisingly found that a frozen dessert that meets these challenges can be provided if a completely different format and formulation is used. Thus, in contrast to the oil-in-water emulsion of a typical frozen dessert, the frozen dessert of the present invention comprises a water-in-oil (also referred to as "wio", "w / o") emulsion.

[0022] Frozen confections comprising water-in-oil emulsions have been described in the prior art, in particular JP 64 / 063,341 attempts to provide such a product. However, as will be seen in the examples below, the resulting product is not an acceptable frozen confection due to textural, organoleptic and palatability deficiencies.

[0023] Therefore, there is a need for improved frozen desserts which address the above challenges.

[0024] The present invention provides a water-in-oil emulsion suitable for producing frozen desserts; a precursor oil phase suitable for preparing the water-in-oil emulsion from a precursor oil phase and a precursor water phase; a method for preparing the water-in-oil emulsion from the precursor; a method for preparing a frozen dessert from the water-in-oil emulsion of the first aspect; and a frozen dessert comprising the water-in-oil emulsion. Summary of the invention

[0025] Water-in-oil emulsions for preparing frozen desserts

[0026] In a first aspect, the present invention provides a water-in-oil emulsion for preparing a frozen dessert, the emulsion comprising a water phase (WP) and an oil phase (OP) in a weight ratio (WP:OP) of 94:6 to 70:30, wherein:

[0027] - the oil phase comprises at least edible oil and an emulsifier, and the average HLB of the emulsifier is 0.1-5;

[0028] - the aqueous phase comprises at least water and one or more freezing point depressants;

[0029] - the emulsion comprises at least (W×A) wt% of an emulsifier based on the weight of the emulsion, wherein:

[0030] W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion; and

[0031] A is 0.0001;

[0032] - the emulsion comprises up to (0×0.2) wt% of an emulsifier based on the weight of the emulsion, wherein:

[0033] O is the proportion of the oil phase in the emulsion, expressed as a weight percentage of the total emulsion;

[0034] - the emulsion comprises 4-40 wt% of one or more freezing point depressants based on the weight of the emulsion; and

[0035] - the temperature at which the edible oil contains 25 wt% of solid fats relative to the weight of the edible oil is lower than the temperature at which the aqueous phase contains 25 wt% of ice relative to the weight of the aqueous phase.

[0036] Method for preparing water-in-oil emulsion

[0037] In a second aspect, the present invention provides a method for preparing the water-in-oil emulsion of the first aspect, the method comprising the following steps:

[0038] -Preparing a precursor aqueous phase comprising:

[0039] 45-96 wt % of water by weight of the precursor aqueous phase;

[0040] One or more freezing point depressants in an amount of 4-40 wt % based on the weight of the precursor aqueous phase;

[0041] -Preparation of a precursor oil phase comprising:

[0042] 90-97.9 wt% of the precursor oil phase in an amount of edible oil; and

[0043] An emulsifier in an amount of 0.05-20 wt% of the precursor oil phase, wherein the average HLB of the emulsifier is 0.1-5,

[0044] wherein the temperature at which the edible oil contains 25 wt% of solid fat accounting for the weight of the edible oil is lower than the temperature at which the water phase contains 25 wt% of ice accounting for the weight of the water phase;

[0045] - combining the precursor water phase and the precursor oil phase while mixing to form the water-in-oil emulsion, wherein the weight ratio of the water phase (WP) to the oil phase (OP) of the obtained water-in-oil emulsion is from 94:6 to 70:30;

[0046] - wherein the emulsification step is carried out at a temperature above the melting point of the aqueous phase of said precursor.

[0047] precursor oil phase

[0048] The precursor oil phase contains:

[0049] - edible oil in an amount of 90-97.9 wt% of the weight of the precursor oil phase; and

[0050] - an emulsifier in an amount of 0.05-20 wt% of the precursor oil phase, the average HLB of the emulsifier being 0.1-5,

[0051] The edible oil has a melting point lower than the melting point of the precursor aqueous phase used to prepare the water-in-oil emulsion.

[0052] Preferably, the precursor oil phase comprises edible oil in an amount of at least 91 wt %, more preferably at least 92 wt %, more preferably at least 93 wt %, even more preferably at least 94 wt %, even more preferably at least 95 wt %, even more preferably at least 96 wt % based on the weight of the precursor oil phase.

[0053] Preferably, the precursor oil phase comprises edible oil in an amount of at most 97.8 wt%, more preferably at most 97.7 wt%, at most 97.6 wt%, at most 97.5 wt%, at most 97.4 wt%, at most 97.3 wt%, at most 97.2 wt%, or even at most 97.1 wt%, based on the weight of the precursor oil phase.

[0054] Preferably, the precursor oil phase comprises an emulsifier in an amount of at least 0.1 wt %, more preferably at least 0.25 wt %, at least 0.5 wt %, at least 1 wt %, at least 2.5 wt %, or even at least 5 wt % based on the weight of the precursor oil phase.

[0055] Preferably, the precursor oil phase comprises an emulsifier in an amount of at most 10 wt %, more preferably at most 9 wt %, at most 8.5 wt %, at most 8 wt %, at most 7.5 wt %, at most 7 wt %, at most 6.5 wt %, or even at most 6 wt %, based on the weight of the precursor oil phase.

[0056] Precursor water phase

[0057] The present invention uses a precursor aqueous phase to prepare the water-in-oil emulsion of the first aspect, and the precursor aqueous phase comprises:

[0058] - water in an amount of 45-96 wt % based on the weight of the precursor aqueous phase;

[0059] - one or more freezing point depressants in an amount of 4 to 40 wt% based on the weight of the precursor aqueous phase.

[0060] Preferably, the aqueous precursor phase comprises water in an amount of at least 50 wt%, more preferably at least 55 wt%, at least 60 wt%, or even at least 65 wt%, based on the weight of the aqueous precursor phase.

[0061] Preferably, the aqueous precursor phase comprises water in an amount of at most 90 wt%, more preferably at most 80 wt%, at most 75 wt%, or even at most 70 wt% based on the weight of the aqueous precursor phase.

[0062] Preferably, the precursor aqueous phase comprises one or more freezing point depressants in an amount of at least 5 wt %, more preferably at least 7.5 wt %, at least 10 wt %, at least 15 wt %, or even at least 20 wt % based on the weight of the precursor aqueous phase.

[0063] Preferably, the precursor aqueous phase comprises one or more freezing point depressants in an amount of at most 35 wt%, more preferably at most 30 wt%, more preferably at most 25 wt%, based on the weight of the precursor aqueous phase.

[0064] Preferably, the expansion ratio of the precursor aqueous phase is 10%-500%, more preferably 20%-450%, 30%-400%, 40%-350%, 50%-300%, 60%-275%, 70%-250%, 80%-200%, or even 90%-150%.

[0065] Method for preparing frozen desserts

[0066] In a third aspect, the present invention provides a method for preparing a frozen confection, wherein the water-in-oil emulsion of the first aspect is statically frozen.

[0067] Preferably, the emulsion is frozen at a temperature not lower than -20°C, more preferably not lower than -18°C, more preferably not lower than -16°C, more preferably not lower than -14°C, more preferably not lower than -12°C, more preferably not lower than -10°C.

[0068] Frozen desserts

[0069] In a fourth aspect, the present invention provides a frozen dessert comprising the water-in-oil emulsion of the first aspect. The frozen dessert of the fourth aspect may be prepared using the method of the third aspect.

[0070] Preferably, the frozen confection has an overrun of 10-200%, more preferably 20-190%, 30-180%, 40-170%, 50-160%, 60-150%, 70-140%, 80-130%, or even 90-120%. DETAILED DESCRIPTION OF THE INVENTION

[0072] Frozen desserts

[0073] Definitions and descriptions of various terms and techniques used in the production of frozen confections are found in Ice Cream, 7th Edition, H. Douglas Goff and Richard W. Hartel (2013), Kluwer Academic / Plenum Publishers. Unless otherwise stated, all percentages are by weight, except for percentages mentioned in relation to overrun.

[0074] As used herein, the term frozen dessert refers to a dessert that is intended to be eaten in a frozen state, ie under conditions where the temperature of the dessert is below 0°C, preferably under conditions where the dessert contains a large amount of ice.

[0075] Weight ratio of water phase to oil phase

[0076] In the present invention, the liquid to be dispersed is the aqueous phase, and the liquid into which the aqueous phase is dispersed is the oil phase. Therefore, a water-in-oil emulsion is prepared by combining a precursor oil phase with a precursor aqueous phase. The oil phase is the continuous phase of the emulsion. The present invention can provide a stable water-in-oil emulsion having an extremely low level of oil phase relative to the aqueous phase, specifically a water-in-oil emulsion in which 94 wt% of the aqueous phase is dispersed in only 6 wt% of the oil phase, i.e., the weight ratio of the aqueous phase to the oil phase (WP:OP) is 94:6. Preferably, the weight ratio of the aqueous phase to the oil phase (WP:OP) is at most 92:8, more preferably 90:10, more preferably 85:15, more preferably 80:20, more preferably 75:25. Preferably, the weight ratio of the aqueous phase to the oil phase (WP:OP) is at least 72.5:27.5.

[0077] Cooking Oil

[0078] Edible means suitable for human consumption. Oil refers to a neutral, non-polar chemical substance that is a viscous liquid at ambient temperature (about 20° C.) and is both hydrophobic and lipophilic. In the context of the present invention, edible oil refers to an oil that is liquid at the temperature at which the precursor oil phase is prepared. The main component of edible oil is triacylglyceride, which contains three fatty acids linked together by a glycerol molecule.

[0079] Types of cooking oil

[0080] Preferably, the edible oil is selected from: rice bran oil, avocado oil, safflower oil, peanut oil, hazelnut oil, soybean oil, almond oil, sunflower seed oil, pumpkin seed oil, rapeseed oil, corn seed oil, grape seed oil, linseed oil or walnut oil or a combination thereof. More preferably, the edible oil is selected from: corn seed oil, grape seed oil, linseed oil, sunflower seed oil, rapeseed oil or walnut oil or a combination thereof.

[0081] Solidification point of edible oil relative to water phase

[0082] It has been found that the water-in-oil emulsions of the present invention require that the temperature at which the edible oil begins to solidify is lower than the temperature at which the water phase begins to solidify. For the avoidance of doubt, it is the solidification of the edible oil itself, as opposed to the solidification of the entire oil phase, that is important. Furthermore, it is the temperature at which the entire water phase (including other ingredients such as freezing point depressants) begins to solidify, not just the solidification of the water itself, that is important.

[0083] Without wishing to be bound by theory, it is believed that when the requirement that the freezing point of the edible oil is lower than the freezing point of the aqueous phase is met, the result is that when the emulsion is frozen to prepare a frozen dessert, the aqueous phase solidifies first and ice crystals are therefore formed at a stage where the edible oil (and therefore the continuous phase of the emulsion) remains liquid. Thus, the oil phase remains plastic and is not destroyed by the formation of ice crystals in the aqueous phase. Any edible oil that meets this requirement can be used in the present invention.

[0084] Those skilled in the art will appreciate that determining the specific freezing point of a liquid (i.e. the point at which fat crystals begin to form in the case of an edible oil or ice crystals begin to form in the case of an aqueous phase) may be difficult to determine experimentally. Therefore, in the context of the present invention, the temperature at which the edible oil contains 25 wt% solid fat is used for the edible oil. Similarly, the temperature at which the aqueous phase contains 25 wt% ice is used for the aqueous phase.

[0085] Therefore, the requirement of the present invention is that the temperature at which the edible oil contains 25 wt % of solid fat is lower than the temperature at which the aqueous phase contains 25 wt % of ice.

[0086] The temperature at which cooking oil contains 25% solid fat

[0087] The temperature at which an edible oil contains 25 wt% solid fat can be determined using differential scanning calorimetry (DSC), a thermal analysis technique in which the difference between the amount of heat required to raise the temperature of a sample and a reference is measured as a function of temperature. When a solid oil sample melts into a liquid oil, more heat is required to flow into the sample to raise its temperature at the same rate as the reference. This is due to the sample absorbing heat as it undergoes an endothermic phase change from solid to liquid. By observing the difference in heat flow between the sample and the reference, a differential scanning calorimeter is able to measure the amount of heat absorbed or released during this phase change, and thus identify the melting point of the sample.

[0088] DSC measurements were performed using a differential scanning calorimeter DSC 8500 (Pyris, Perkin Elmer Inc.). Before the actual measurement, the instrument was calibrated with indium (ΔHf=28.5J / g, melting temperature=156.6°C). About 20mg of the oil sample was placed in a small aluminum pan. An empty pan was used as a reference while measuring the change in heat capacity. The following measurements were performed. First, the sample was kept at 20°C for 5 minutes. A heating step was then performed to 60°C. After this heating step, the sample was cooled to -80°C, followed by a final heating step to 60°C again. For both the heating and cooling steps, a temperature gradient of 2°C / minute was applied. The data obtained from the measurement was exported to Excel for further analysis, and the relevant points were identified from the resulting DSC curve by the following steps: First, the uncorrected heat flow was corrected by dividing by the sample weight. Then, a baseline was constructed by fitting a 4th-order polynomial in the absence of data at extreme temperatures (below -60°C and above 40°C) representing a phase change (crystallization / melting). The baseline was then subtracted from the complete data set and the remaining area was integrated. The fully integrated area was converted to 100% and a partial integration was performed from -80°C to each other temperature to obtain a curve of solid fat content expressed as a percentage. The temperature at which the edible oil contained 25 wt% solid fat was determined from the resulting curve.

[0089] The table below provides the temperatures at which various edible oils contain 25 wt% solid fat.

[0090] Oil Temperature at which oil contains 25 wt% solid fat (°C) olive oil 0 Rice bran oil -6 Avocado Oil -4 Safflower Oil -7 Peanut Oil -6 Hazelnut Oil -6 Soybean Oil -4 Almond Oil -7 Sunflower Oil -13 Pumpkin Seed Oil -12 Hemp seed oil -13 Rapeseed Oil -13 Corn Oil -17 Grapeseed Oil -20 Flaxseed oil -24 Walnut Oil -26

[0091] The temperature at which the aqueous phase contains 25% ice

[0092] As described herein, the aqueous phase comprises water and a freezing point depression agent.The temperature at which the aqueous phase contains 25 wt% ice can also be determined using DSC as described above, or can be calculated using techniques known in the art.

[0093] Preferably, the temperature of the edible oil when it contains 25 wt% solid fat is at least 4°C lower than the temperature of the aqueous phase when it contains 25 wt% ice, more preferably at least 6°C lower, still more preferably at least 8°C lower, even more preferably at least 10°C lower, more preferably at least 12°C lower, still more preferably at least 14°C lower, and most preferably at least 16°C lower.

[0094] Preferably, the temperature at which the edible oil contains 25 wt% solid fat is at most 30°C lower than the temperature at which the aqueous phase contains 25 wt% ice.

[0095] As a valid example:

[0096] - When the temperature of the edible oil containing 25 wt% solid fat is at least 4°C lower than the temperature of the water phase containing 25 wt% ice, and the temperature of the water phase containing 25 wt% ice is -1°C, then the temperature of the edible oil is at least -5°C (i.e.

[0097] -1°C minus 4°C = -5°C).

[0098] Similarly:

[0099] - When the temperature of the edible oil containing 25 wt% solid fat is at least 8°C lower than the temperature of the water phase containing 25 wt% ice, and the temperature of the water phase containing 25 wt% ice is -2°C, then the temperature of the edible oil is at least -10°C

[0100] (ie -2°C minus 8°C = -10°C).

[0101] Emulsifier

[0102] Emulsifier refers to one or more surfactants that can be used when it is necessary to reduce the surface tension, particularly for food processing. When a liquid needs to be dispersed in another immiscible liquid, it is necessary to reduce the surface tension. As mentioned, in the present invention, the liquid to be dispersed is the aqueous phase, and the liquid into which the aqueous phase is dispersed is the oil phase. The oil phase is therefore the continuous phase. In the present invention, an emulsifier is one of the factors necessary to enable the water-in-oil emulsion of the present invention to be used in the preparation of frozen desserts.

[0103] Emulsifier Type

[0104] The emulsifier may be selected from the following:

[0105] Glycerol fatty acid esters, including monoglycerides, preferably unsaturated monoglycerides;

[0106] Organic acid esters of monoglyceride, including acetate of monoglyceride (acetylated MG-ACETEM), citrate of monoglyceride (CITREM), lactate of monoglyceride (LACTEM), succinate of monoglyceride, preferably acetate of monoglyceride and / or lactate of monoglyceride;

[0107] Polyglycerol esters of fatty acids, including PGE;

[0108] Sorbitan esters of fatty acids, including sorbitan monostearate, tristearate, monolaurate, monooleate and monopalmitate;

[0109] Propylene glycol esters of fatty acids, including propane-1,2-diol (propylene glycol) esters of fatty acids;

[0110] Sucrose esters of fatty acids, including sucrose glycerides;

[0111] Polyglycerol polyrhizoleate (PGPR);

[0112] Lecithin (a mixture containing phospholipids as the main component found widely in animals and plants), preferably soy lecithin, examples include Yelkin and Beakin;

[0113] Egg yolk (usually a mixture of lipids (30%), proteins (16%), carbohydrates (carbs) (3.5%) and 9% lecithin);

[0114] or a mixture thereof.

[0115] More preferably, the emulsifier is selected from: glycerol fatty acid esters, organic acid esters of monoglyceride, polyglycerol esters of fatty acids, sorbitan esters of fatty acids, propylene glycol esters of fatty acids, sucrose esters of fatty acids, polyglycerol ricinoleate, lecithin and egg yolk, or a mixture thereof.

[0116] Hydrophile-Lipophile Balance (HLB)

[0117] HLB refers to the hydrophilic-lipophilic balance of an emulsifier. HLB is a measure of the degree of hydrophilicity or lipophilicity of a surfactant molecule. HLB can be calculated from the surface properties of the molecule. The average HLB of a mixture of surfactants of the same component type can be calculated as:

[0118]

[0119] The average HLB of the emulsifier in the present invention is 0.1 to 5. Preferably, the average HLB of the emulsifier is 0.25 to 4, more preferably 0.5 to 3.5, more preferably 1 to 3, even more preferably 1 to 2.

[0120] Amount of emulsifier by weight in the emulsion

[0121] It will be appreciated that as the proportion of the aqueous phase increases, the amount of oil phase available to form the continuous oil phase of the water-in-oil emulsion will decrease accordingly, and taking this into account, it is therefore desirable to have more emulsifier. Therefore, the minimum amount of emulsifier by weight in the emulsion is expressed as (W×A), where W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion, and A is a factor to ensure a sufficient level of emulsifier. A is therefore at least 0.0001. Preferably A is 0.00025, more preferably 0.0005, more preferably 0.001, more preferably 0.0025, more preferably 0.005, more preferably 0.01, more preferably 0.025, more preferably 0.05.

[0122] It will also be understood that the emulsifier is provided as part of the oil phase and that therefore an increase in the proportion of the emulsifier in the oil phase will also reduce the amount of oil available to form the continuous oil phase of the water-in-oil emulsion. Thus, the maximum amount of emulsifier by weight in the emulsion is at most (0×0.2), where 0 is the proportion of the oil phase (including all other components of the oil phase, i.e., the oil, the emulsifier and other ingredients of the oil phase) in the emulsion, expressed as a weight percentage of the total emulsion, i.e., the level of emulsifier does not exceed 20 wt% of the oil phase. Preferably, the maximum amount of emulsifier by weight in the emulsion is at most (0×0.175) wt%, more preferably (0×0.15) wt%, or even (0×0.1) wt%.

[0123] Freezing point depressants

[0124] Freezing point depressants are food ingredients that can lower the freezing point of water. They are usually small molecules that can be dissolved in water at high concentrations.

[0125] Preferably, the emulsion comprises one or more freezing point depressants in an amount of at least 5 wt %, more preferably at least 7.5 wt %, at least 10 wt %, at least 15 wt % or even at least 20 wt % of the weight of the emulsion. Preferably, the emulsion comprises one or more freezing point depressants in an amount of at most 37.5 wt %, more preferably at most 35 wt %, at most 30 wt %, or even at most 27.5 wt % of the weight of the emulsion.

[0126] Preferably, the one or more freezing point depressants are selected from sugars, salts or sugar alcohols or mixtures thereof. Preferably, the sugar is a monosaccharide, preferably glucose, fructose, galactose or mixtures thereof, or a disaccharide, preferably sucrose, lactose, maltose or mixtures thereof. Preferably, the sugar alcohol is selected from the following: glycerol, erythritol, sorbitol, maltitol, mannitol and lactitol. Oligosaccharides may optionally be included as freezing point depressants.

[0127] Fat structurants

[0128] Fat structurants refer to fats whose melting point is higher than that of edible oils and also higher than the temperature at which the emulsion is prepared. Therefore, when used, the fat structurants are present as small particles in the precursor oil phase when the emulsion is formed.

[0129] Fat structurants can be made from a mixture of low melting point oil and high melting point oil by spiral heat exchanger processing. In this process, the oil mixture is cooled to a temperature where the low melting point oil is still liquid but the high melting point oil is already solid, and pumped through a container with a scraper. The container is also cooled to this low temperature, and although a solid fat layer tends to form on the container surface, this layer is constantly scraped off, which results in small disc-like particles. The particles are small but sufficient to structure the oil phase, increase the viscosity of the emulsion and the freeze-thaw stability of the resulting frozen dessert.

[0130] The fat structurant can be a single fat or a mixture of multiple fats, and the possible sources are animal, dairy or vegetable fats. Vegetable fats are preferred.

[0131] Without wishing to be bound by theory, it is believed that the small fat crystals of the fat structurant form a permeable network throughout the oil phase, giving the oil phase resilience. Due to the thinner the oil phase is stretched by emulsifying the water phase into the oil phase, these fat crystals are more and more used as oil film stabilizers for stabilizing the intermediate state emulsion. During freezing, the crystals provide tensile strength for the oil film, stack and slide on each other, thereby providing a barrier between the ice crystals formed during freezing. The small fat crystals in the oil phase provide tensile strength for the oil phase, protecting it from the influence of ice crystal growth in the water phase during freezing. In environmental applications where the emulsion is supplied at room temperature and the emulsion is frozen elsewhere (e.g., at a consumer location), it is believed that this principle is one of the mechanisms for achieving environmentally stable emulsions, and it is believed to work in environmental oil phases or environmental water-in-oil emulsions.

[0132] The structural fat is present in an oil phase based on an oil that is liquid at ambient temperature (20° C.). The oil may be any oil, preferably an oil of vegetable origin. The fat structurant is preferably a triglyceride fat. It may be a natural fat such as palm kernel fat or coconut fat, or a modified fat such as a fat or fat mixture that has been hydrogenated, transesterified, enzymatically transesterified, fractionated (wet or dry) or blended. The fat structurant is present in the form of small crystals, which can be achieved by different methods.

[0133] Hydrogenation changes the unsaturation of fatty acids, and therefore changes the fatty acid composition. This makes it possible to make plastic fats from liquid oils. Transesterification retains the fatty acid composition but changes the distribution of fatty acids on the glycerol backbone. Transesterification can be carried out chemically or by means of enzymes. Usually, they are not suitable for the mixture of two different fats as structural fats themselves to carry out transesterification. Compared with starting material, the gained transesterified fat can have the structural properties of improvement.

[0134] Fat structurant oils can be fractionated according to their triglyceride composition. Wet fractionation or dry fractionation is possible. For example, medium fractionated palm stearin (mfPOs) have been shown to be a viable alternative to hardened fats.

[0135] Fats that have been shown to act as fat structurants due to their N-line (temperature-dependent solid fat content) are

[0136] - fully hardened high erucic acid rapeseed oil, the main triglyceride fraction of which contains long-chain saturated fatty acids of C18 and C22 and has a melting point of 70° C. (referred to herein as “RPh70”),

[0137] - hardened soybean oil (BO65) or hardened palm oil (referred to herein as "PO58"),

[0138] - fully hardened sunflower oil, melting point 69° C. (referred to herein as “SF69”),

[0139] - An interesterified fat mixture having a melting temperature of 48°C (referred to herein as "ines48").

[0140] Preferably, the fat structurant has a solid fat content of at least 90 wt% at the emulsification temperature.

[0141] The fat structurant can be combined with the edible oil by mixing the fat structurant and the oil at a temperature above the melting temperature of the structurant and cooling the mixture to below room temperature in a spiral heat exchanger, whereby small crystals of the fat structurant oil are formed on the surface of the spiral heat exchanger, which are continuously removed from the surface of the spiral heat exchanger by a rotating scraper. The resulting mixture is a high viscosity, pourable oil / fat mixture.

[0142] Alternatively, the fat structurant is available as a powder in a very small particle (fat crystal) format. This powder can be mixed with liquid edible oil at room temperature.

[0143] Preferably, the fat structurant is hydrogenated fat. More preferably, the fat structurant is selected from:

[0144] - Hardened rapeseed oil, melting point 70°C (RPh70),

[0145] - fractionated palm oil, melting point 58°C (PO58),

[0146] - hardened sunflower oil, melting point 69°C (SF69), and

[0147] - interesterified fats, melting point 48°C (Ines 48), or combinations thereof.

[0148] Preferably, the oil phase of the emulsion comprises at least 0.05 wt% fat structurant, more preferably at least 0.1 wt%, more preferably at least 0.2 wt%, more preferably at least 0.3 wt%, more preferably at least 0.4 wt% based on the weight of the emulsion.

[0149] Preferably, the oil phase of the emulsion comprises at most 10 wt% fat structurant, more preferably at most 7.5 wt%, at most 5 wt%, at most 2.5 wt%, at most 1 wt%, or even at most 0.5 wt% by weight of the emulsion.

[0150] Where a fatty structurant is included in the oil phase of the emulsion, the emulsification step is carried out at a temperature below the melting point of any such fatty structurant.

[0151] Structuring agent

[0152] Preferably, the aqueous phase comprises one or more structurants. Structurants refer to ingredients that control the viscosity of the aqueous phase of the emulsion. Preferably, the structurant is in the form of a thickener such as fiber, polysaccharide or protein. Polysaccharides or proteins can also form gels that are not only viscous but also elastic. Viscosity and elasticity can be measured by rheology. The product may contain a structurant such as a polymer.

[0153] Preferably, the aqueous phase of the emulsion comprises at least 0.1 wt% structurant, more preferably at least 0.2 wt%, at least 0.3 wt%, at least 0.4 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 3 wt%, or even at least 4 wt% based on the weight of the emulsion.

[0154] Preferably, the aqueous phase of the emulsion comprises at most 10 wt% structurant, more preferably at most 9 wt%, at most 8 wt%, at most 7 wt%, at most 6 wt%, or even at most 5 wt% by weight of the emulsion.

[0155] Preferably, the viscosity of the aqueous phase is from 10 times lower to 1000 times higher than the viscosity of the oil phase, more preferably from 2 times higher to 100 times higher, more preferably from 5 times higher to 75 times higher, more preferably from 5 times higher to 50 times higher (measured in 1 / s at the emulsification temperature). The emulsification temperature refers to the temperature at which the aqueous phase and the oil phase combine to form the water-in-oil emulsion of the present invention.

[0156] Preferably, the structurant is selected from galactomannan, glucomannan, xanthan gum, carrageenan (iota, kappa, lambda, etc.), agar, starch, pectin (HM, LM-pectin), alginates, cellulose derivatives (methylcellulose, ethylcellulose, HPMC, CMC), plant fibers (citrus fiber, tomato fiber, microfibrillated fiber), gelatin, (acid) latex gel, gellan gum or mixtures thereof. Materials from tamarind flowers, furcellaran, tragacanth gum, karaya gum or mixtures thereof may also be used.

[0157] The most preferred structurants are iota-carrageenan and / or modified tapioca starch because the water phase is the correct viscosity when mixed into the oil to form the emulsion and gels directly after emulsification occurs as well as providing additional emulsion stability.

[0158] Nucleating Agent

[0159] In order to form a frozen dessert, the water in the aqueous phase needs to become ice (i.e. nucleate). This can be achieved by significantly supercooling a large amount of water, the smaller the volume, the more significant the supercooling required to achieve this so-called homogeneous nucleation. Since the water-in-oil emulsion of the present invention contains water in the form of small droplets, the supercooling for homogeneous nucleation needs to be in the order of about 35°C for droplets of 10 μm in diameter. Therefore, nucleating agents allow freezing at higher temperatures. Nucleating agents refer to particles that act by promoting heterogeneous nucleation in each droplet.

[0160] Preferably, the aqueous phase of the emulsion comprises at least 0.1 wt% nucleating agent, based on the weight of the emulsion, more preferably at least 0.2 wt%, at least 0.3 wt%, at least 0.4 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 3 wt%, and most preferably at least 3.5 wt%.

[0161] Preferably, the aqueous phase of the emulsion comprises at most 10 wt% nucleating agent, more preferably at most 9 wt%, at most 8 wt%, at most 7 wt%, at most 6 wt%, at most 5 wt%, most preferably at most 4 wt%, based on the weight of the emulsion.

[0162] Preferably, the nucleating agent comprises 0.5-20wt% protein powder, preferably skimmed milk powder, vegetable protein powder, soy flour, pulses, pea flour, or a mixture thereof. The nucleating agent may also comprise Laponite or Bentonite, preferably 0.1wt% to 1wt% Laponite or Bentonite.

[0163] Inflation

[0164] The term aeration refers to the intentional incorporation of gas into the emulsion, for example by mechanical means. The gas may be any gas, but in frozen confections is preferably a food grade gas such as air, nitrogen, nitrous oxide or carbon dioxide. Thus, the term "aeration" is not limited to aeration with air, and also encompasses "gasification" with other gases.

[0165] The degree of inflation is measured as "inflation rate" (unit "%), which is defined as:

[0166]

[0167] Preferably, the water-in-oil emulsion of the present invention has an overrun of 10% to 200%, 20% to 190%, 30% to 180%, 40% to 170%, 50% to 160%, 60% to 150%, 70% to 140%, 80% to 130%, or even 90% to 120%.

[0168] precursor oil phase

[0169] As described above, the water-in-oil emulsion of the first aspect can be prepared by combining a precursor oil phase with a precursor water phase. The precursor oil phase comprises:

[0170] - 90-97.9 wt% of the precursor oil phase in the form of edible oil; and

[0171] - 0.05-20 wt% of the precursor oil phase in an emulsifier, wherein the average HLB of the emulsifier is 0.1-5,

[0172] The melting point of the edible oil is lower than the melting point of the precursor water phase.

[0173] For the avoidance of doubt, edible oil, emulsifier, melting point (ie the freezing point of the edible oil relative to the aqueous phase) and HLB are as defined above. Similarly, as detailed above, the oil phase may additionally comprise a fat structurant.

[0174] Method for preparing a precursor oil phase

[0175] The precursor oil phase can be prepared in a manner known to those skilled in the art. For example, the oil phase ingredients can be added to the structured oil in a mixer and dissolved in the oil. In the case of using fat structurants, they are already present in the oil. For example, a food mixer with a balloon whisk is used to mix the ingredients. During this process, air can be incorporated into the oil phase, for example, an overrun of 50% to 200%. It has been found that most of this overrun is retained after emulsification, providing an overrun of up to 10% in the emulsion product. The overrun in the oil phase can also be generated using an aerator such as the Trefa T50 (Trefa Continu Aerating Systems BV).

[0176] Precursor water phase

[0177] The precursor aqueous phase is combined with the precursor oil phase to form the water-in-oil emulsion of the first aspect. As described above, the precursor aqueous phase comprises:

[0178] - 45-96 wt% of water based on the weight of the precursor aqueous phase; and

[0179] - 4-40 wt% of one or more freezing point depressants, based on the weight of the precursor aqueous phase.

[0180] For the avoidance of doubt, the detailed descriptions regarding water content, freezing point depressant(s) are as described above. Similarly, as described above, the aqueous phase may optionally contain one or more structurants and / or one or more nucleating agents.

[0181] Freezing point of water phase

[0182] As described herein, the aqueous phase comprises water and a freezing point depression agent.The temperature at which the aqueous phase contains 25 wt% ice can be determined using DSC as described above, or can be calculated using techniques known in the art.

[0183] Measurement of Precursor Aqueous Phase Viscosity

[0184] The viscosity of both the precursor water phase and the precursor oil phase can be measured by rheology. The protocol for measuring viscosity is as follows:

[0185] The instrument AR G2 (TA Instruments, New Castle, Delaware, USA) was used in parallel plate geometry, which was a 4 cm plate with a sandblasted surface and a gap setting of 1 mm. The following measurement profiles were defined in the instrument software: viscometry, steady-state flow test. The measurement temperature in the rheometer software was set to 25°C and a steady-state flow test was defined.

[0186] The following parameters in the software are set to the indicated values:

[0187] - Pre-shear: duration 10 seconds, shear stress 0.79Pa.

[0188] - Equilibration time: 2 minutes.

[0189] - Test 1: Steady flow test, logarithmic, 6 points per decade, shear rate range 0.01 / s-500 / s. Sample period: 10 seconds

[0190] - Steady state: Tolerance 5%, 3 consecutive measurements within tolerance, maximum point time 1 minute.

[0191] - Test 2 (reverse circulation): Steady flow test, logarithmic, 6 points per decade, shear rate range 500 / s to 0.01 / s. Sample period: 10 seconds

[0192] - Steady state: Tolerance 5%, 3 consecutive measurements within tolerance, maximum point time 1 minute.

[0193] Load 1.5-2 ml of sample and lower the plate to the gap distance. Then, start the measurement. Take the viscosity value of 1 / s in the reverse cycle to reflect the viscosity.

[0194] Method for preparing a precursor aqueous phase

[0195] The precursor aqueous phase can be prepared in a manner known to those skilled in the art. For example, the granular and powdered ingredients of the aqueous phase can be dry mixed with a freezing point depressant for rapid and lumpy dissolution. The powder mixture can be slowly added to warm water (about 50° C.) and mixed. After smooth dissolution, the mixture is typically pasteurized at 90° C. for 6 minutes, which can also gelatinize the starch (if used). The mixture is cooled to room temperature or below.

[0196] Aeration of the precursor aqueous phase

[0197] The precursor aqueous phase may be aerated prior to emulsification with the oil phase to provide an aerated product.

[0198] Aeration may be achieved by mixing the prepared aqueous phase for about 30 minutes at a constant temperature of about 5° C. This may be done by means known to those skilled in the art, for example using a Kenwood food mixer with the beater attachment set to maximum speed.

[0199] Alternatively, aeration can be achieved by high shear mixing, preferably during cooling, or by using a dedicated aerator with a back pressure regulator (typically 10 input atmospheres, 2 output atmospheres) to enhance further expansion of the bubbles after the outlet.

[0200] Aeration may include the addition of a suitable aerating agent (air stabilizer), but this is not necessary, as the formulations of the present invention surprisingly deliver a stable aerated product. Suitable aerating agents (air stabilizers) include, but are not limited to, PGE215 and protein powder.

[0201] Preferably, the precursor aqueous phase has a swelling ratio of 10% to 500%, more preferably 20% to 450%, more preferably 30% to 400%, more preferably 40% to 350%, more preferably 50% to 300%, more preferably 60% to 275%, more preferably 70% to 250%, more preferably 80% to 200%, more preferably 90% to 150%.

[0202] Method for preparing water-in-oil emulsion

[0203] In a second aspect, the present invention provides a method for preparing the water-in-oil emulsion of the first aspect, wherein the method comprises an emulsification step, which is performed at a temperature higher than the melting point of the precursor aqueous phase.

[0204] The emulsification step is preferably carried out at a temperature at which the fat structurant (if used) is solid (e.g. < 40°C) and the aqueous phase is not too liquid but not a hard gel (e.g. between 40°C and 10°C but not below 0°C).

[0205] Without wishing to be bound by theory, it is believed that the emulsification step should be conducted at a temperature above the melting point of the precursor water phase so that the precursor water phase is liquid enough to mix with the precursor oil phase under shear conditions. Additionally, this step should be conducted at a temperature above the melting point of the precursor oil phase so that the precursor oil phase is liquid enough to mix with the precursor water phase under shear conditions. Finally, it is believed that the temperature at which the emulsification step is conducted should be below the melting point of any fat structurant in the precursor oil phase so that the fat structurant can crystallize and function as described herein.

[0206] The resulting emulsion can be stored at ambient temperature or in a refrigerator (about 5°C) for a long period of time and can be provided as an emulsion product that is frozen when consumed.

[0207] In another method, the precursor water phase and the precursor oil phase can be combined in a precursor water phase to precursor oil phase weight ratio of 94:6 to 70:30 (based on the weight of the resulting water-in-oil emulsion) prior to mixing; and then mixed; wherein the emulsification temperature is above the melting point of the precursor water phase and below the melting point of any fatty structurant in the precursor oil phase.

[0208] It can be easily understood that this very simple production method has many advantages over the standard method for producing frozen desserts. For example, only the precursor aqueous phase needs to be pasteurized. High pressure homogenization is not required. The temperature scheme for adding ingredients is simpler. No ripening premix is ​​required. The emulsion, once made, is stable over time, which makes it more suitable for subsequent processing.

[0209] Method for preparing frozen desserts

[0210] The present invention provides a method for preparing a frozen confection, wherein the water-in-oil emulsion of the first aspect is statically frozen (ie frozen with minimal or no: stirring; shearing; agitation; or aeration).

[0211] Preferably, the emulsion is frozen at a temperature of -20°C, more preferably -18°C, more preferably -16°C, more preferably -14°C, more preferably -12°C, more preferably -10°C.

[0212] It will be appreciated that being able to utilize static freezing has significant advantages. Firstly, it provides a simpler process than standard ice cream production methods. In fact, static freezing cannot be used to make standard oil-in-water emulsions. It also consumes less energy than equipment such as scraped surface heat exchangers. In addition, the emulsion can be frozen at a higher temperature than typical ice cream production, and therefore less energy is required for temperature extraction and freezing. Additionally, a hardening step is used in conventional processing after the scraped surface heat exchanger, and more energy is required for such standard production, but hardening is not required in the present invention. Finally, the resulting frozen dessert can be prepared and stored at a wide range of freezing temperatures, typically -6°C to -28°C and lower.

[0213] Frozen desserts

[0214] The present invention provides a frozen dessert comprising the emulsion of the first aspect. The frozen dessert comprises a water-in-oil emulsion comprising a water phase (WP) and an oil phase (OP) in a weight ratio (WP:OP) of 94:6 to 70:30, wherein:

[0215] - the oil phase comprises at least edible oil and an emulsifier, and the average HLB of the emulsifier is 0.1-5;

[0216] - the aqueous phase comprises at least water and one or more freezing point depressants;

[0217] - the emulsion comprises at least (W×A) wt% of an emulsifier based on the weight of the emulsion, wherein:

[0218] W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion; and

[0219] A is 0.0001;

[0220] - the emulsion comprises up to (0×0.2) wt% of an emulsifier based on the weight of the emulsion, wherein:

[0221] O is the proportion of the oil phase in the emulsion, expressed as a weight percentage of the total emulsion;

[0222] - the emulsion comprises 4-40 wt% of one or more freezing point depressants based on the weight of the emulsion; and

[0223] - the temperature at which the edible oil contains 25 wt% of solid fats relative to the weight of the edible oil is lower than the temperature at which the aqueous phase contains 25 wt% of ice relative to the weight of the aqueous phase.

[0224] For the avoidance of doubt, all components of the water-in-oil emulsion of the frozen dessert (including but not limited to edible oil, emulsifier, melting point and HLB) are as defined above in relation to the emulsion of the first aspect of the invention and are incorporated into this aspect of the invention mutatis mutandis.

[0225] Other ingredients

[0226] The resulting frozen dessert may also contain other ingredients, for example: flavoring agents including vanilla, strawberry, lemon, orange, and cherry flavoring agents; antioxidants including DBHA, BHT, α-tocopherol, γ-tocopherol, quercetin, anthocyanidins, catechins, ferulic acid, and caffeic acid; coloring agents including tartrazine, riboflavin, curcumin, sunset yellow, zeaxanthin, carotene, carmine, lycopene, canthaxanthin, astaxanthin, apo-8'-carotenal, carmoisine, amaranth, Ponceau 4R, carmine, anthocyanidins, erythrosine, red 2G, indigo carmine, patent blue V, brilliant blue FCF, chlorophyll, chlorophyll copper complex, green S, and black BN; vitamins including vitamins A, D, E, K1, B1, B2, B6, B12, C, biotin, niacin, and folic acid A; or mixtures thereof. These ingredients can be incorporated into the precursor oil phase, the precursor water phase or the emulsion in a suitable manner known in the art. These ingredients can also be added to the frozen dessert afterward. Inclusions can also be added to the product in a similar manner. Inclusions can also be optionally included and can be coated with chocolate, water ice or other suitable coatings.

[0227] As used herein, the term "comprising" encompasses the terms "consisting essentially of" and "consisting of". Where the term "comprising" is used, the steps or options listed do not have to be exhaustive. Unless otherwise stated, numerical ranges expressed in the format of "x to y" are to be understood to include x and y. When specifying any range of values ​​or amounts, any particular upper limit value or amount may be associated with any particular lower limit value or amount. Except in the examples and comparative experiments, or otherwise explicitly stated, all numbers are to be understood as being modified by the word "about". As used herein, unless otherwise stated, the indefinite article "a" or "a kind of" and its corresponding definite article "said" refer to at least one, or one or more.

[0228] The various features of the present invention mentioned in the various sections above are applicable to other sections after making necessary changes in details. Therefore, the features specified in one section can be appropriately combined with the features specified in other sections. Any section headings are added only for convenience and are not intended to limit the present disclosure in any way.

[0229] The following examples are intended to illustrate the present invention and are not intended to limit the present invention to these examples themselves. Example

[0230] In the following examples: Part A describes in detail how the products were prepared and evaluated for their physical attributes (ability to form a correct emulsion, acceptable textural properties at serving temperature); Part B describes in detail how the products were prepared and how their sensory acceptability was evaluated; Part C describes in detail how the prior art failed to provide acceptable oil-phase continuous frozen desserts.

[0231] Material

[0232] Unless otherwise stated, ingredients were sourced from the following suppliers:

[0233] oil phase

[0234] Material Supplier(Location) Sunflower Oil Winterised Sunflower oil(various) Hemp seed oil Supermarket Brands (Hoogvliet, Netherlands) olive oil Supermarket brand (Albert Heijn, Netherlands) RPh70 (contained in a structured oil called "Phase Pro") Unilever Food Solutions (Portugal) Citrem (contained in a structured oil called "Phase Pro") Unilever Food Solutions (Portugal) PGPR'polyglycerol polyrinoleate' Danisco(UK) Sucrose ester S170 Mitsubishi Chemical Foods Corporation(China) Sucrose ester S1170 'Ryoto' Mitsubishi Chemical Foods Corporation (Japan) Sucrose ester DATEM 'Panodan SD / P K' Danisco(UK) Beakin Lecithin Archer Daniels Midland (USA) Yelkin Lecithin Archer Daniels Midland (USA)

[0235] Water Phase

[0236]

[0237]

[0238] method

[0239] The emulsions of the present invention can be prepared in a variety of ways, which demonstrates the versatility of the system. Various preparation methods were employed as shown in the table. Details of these preparation methods are as follows:

[0240] Preparation Method A

[0241] Water Phase - The dry powders were mixed until well blended, then added to water at 80°C and mixed for 10 minutes using a high shear mixer (Silverson L5M-A) running at 10,000 RPM. The solution was then poured into a jacketed mixing vessel and heated above 90°C for 10 minutes for pasteurization. During this time, a paddle mixer rotating at 50 RPM was used to ensure uniform temperature distribution. The water phase was then cooled to 25°C before emulsification.

[0242] Oil Phase - Add the oil to the bowl along with the emulsifier. The two materials were then mixed together using a Kenwood kitchen mixer (Kenwood kMix KMX750RD) at 20°C with a balloon stirring attachment at "speed 3" for 10 minutes. The oil phase was then kept in the bowl for the emulsification step.

[0243] Emulsification - The water phase was gradually added to the oil phase in a Kenwood mixer. This occurred over 3 minutes, during which mixing was at "speed 3". The emulsion was then mixed for a further 7 minutes (10 minutes total). Conductivity was measured using a conductivity meter (HACH Pocket Conductivity HR) to assess whether the system was oil continuous (record measurements 0-10 uS / cm). The emulsion was then divided into 60 g portions and then statically frozen at -25°C.

[0244] Preparation method B

[0245] Aqueous phase – Mix the dry powder until well mixed, then add to water at 60°C and continue mixing for 20 minutes with an overhead impeller (IKARW20). The solution is then heated in a microwave oven (700W, full power) for 5 minutes to dissolve the starch. The aqueous phase is then refrigerated in a refrigerator at 5°C overnight. The next day, the aqueous phase is heated to 40-50°C before emulsification.

[0246] Oil Phase - Add the oil to the bowl along with the emulsifier and mix the materials together using a Kenwood kitchen mixer (Kenwood kMix KMX750RD) at 20°C and using a balloon stirring attachment at maximum speed (marked "Max" on the speed dial). The oil phase is then kept in the bowl for the emulsification step.

[0247] Emulsification - Gradually add the water phase to the oil phase in the bowl of a Kenwood mixer. Add the first quarter of the required amount of water phase at a mixing speed of "Speed ​​6". Then, for the remaining three quarters of the water phase, the mixing speed is reduced to "Speed ​​3". Complete addition takes about 12 minutes. The emulsion is then mixed for an additional 5 minutes while maintaining "Speed ​​3". Conductivity is measured using a conductivity meter (HACH Pocket Conductivity HR) to assess whether the system is oil continuous (record measurements as 0-10uS / cm). The emulsion is then divided into 60g portions and then statically frozen at -18°C or -12°C.

[0248] Preparation Method C

[0249] Water phase – Mix the dry powder until well mixed. Add water at 20°C to a Thermomix container (ThermomixTM31, Vorwerk) and turn on the stirrer to speed setting 2. Gradually add the powder to the water. Once dissolved, increase the speed setting to 4. Then heat the solution to 90°C over 15 minutes and then keep it at 90°C for another 15 minutes. Transfer the water phase to a separate container where it is cooled to 40-50°C before emulsification.

[0250] Oil Phase - Add the oil to the bowl along with the emulsifier and mix the materials together using a Kenwood kitchen mixer (Kenwood kMix KMX750RD) at 20°C, using a balloon stirring attachment at maximum speed (marked "Max" on the speed dial). The oil phase is then kept in the bowl for the emulsification step.

[0251] Emulsification - The water phase was gradually added to the oil phase in a Kenwood mixer (Kenwood kMix KMX750RD). The first quarter of the required amount of water phase was added at a mixing speed of "speed 6". Then, for the remaining three quarters of the amount of water phase, the mixing speed was reduced to "speed 3". It took about 12 minutes to add completely. The emulsion was then mixed for another 5 minutes while maintaining "speed 3". The conductivity was measured using a conductivity meter (HACH Pocket Conductivity HR) to assess whether the system was oil continuous (recorded measurements were 0-10uS / cm). The emulsion was then divided into 60-gram portions, followed by static freezing at -18°C or -12°C (as shown in the table below).

[0252] Preparation method D

[0253] Water Phase - Dry powders (e.g. sugar, milk powder, viscosity modifier, etc.) were mixed until well mixed. The powders were then added to water at 80°C and mixed with a high shear mixer (Silverson L5M-A) for 10 minutes. The solution was then poured into a jacketed mixing vessel and heated above 90°C for 10 minutes for pasteurization. During this time, a paddle mixer rotating at 50 RPM was used to ensure uniform temperature distribution. The water phase was then cooled to 5°C. After cooling, the water phase was added to the bowl of a Kenwood kitchen mixer (Kenwood kMix KMX750RD). The water phase was then mixed while maintaining at 5°C for 30 minutes. The maximum mixing speed (marked "Max" on the speed dial) was used and the water phase was aerated to approximately 300% overrun by a balloon stirring attachment. The water phase was then set aside.

[0254] Oil Phase - Add the oil to the bowl along with the emulsifier and mix the materials together using a Kenwood kitchen mixer (Kenwood kMix KMX750RD) at 20° C., mixing at maximum speed (marked “Max” on the speed dial). The oil phase is then kept in the bowl for the emulsification step.

[0255] Emulsification - Gradually add the water phase to the oil phase in a Kenwood mixer. The speed of the balloon stirring attachment is set to "Speed ​​2". Slowly add the water phase in 10 equal increments over a period of 15 minutes. This emulsifies the water phase into the oil while also dispersing the air within the system. The final expansion of the aerated system is about 50%-65%. Conductivity is measured to assess whether the system is oil continuous (0-10uS / cm). The emulsion is then divided into 60g portions and then static frozen at -25°C.

[0256] Part A – Physical Assessment

[0257] Definitions of Working Examples and Non-Working Examples

[0258] The working example meets the following conditions at the same time:

[0259] When the water and oil phases are combined, a water-in-oil emulsion is formed. This is demonstrated by conductivity measurements using a conductivity meter. In cases where measurements of 0-10 mS / cm are obtained, the system is oil continuous; and

[0260] When statically frozen and then served at a serving temperature of -18°C (representative of freezer temperatures in developed markets) or -12°C (representative of freezer temperatures in emerging markets or elevated, more efficient storage temperatures), the frozen dessert was found by trained testers to be at the correct consistency to be scoopable (i.e. capable of being served as a frozen dessert).

[0261] On the contrary, it is a non-working embodiment if the following conditions exist:

[0262] The emulsion formed was an oil-in-water emulsion. This was confirmed by conductivity measurements using a conductivity meter.

[0263] When measurements greater than 10 mS / cm are obtained, the system is water continuous; and / or

[0264] When statically frozen and served at -12°C (or colder), trained testers found the frozen dessert to be too hard to scoop (ie not to be a frozen dessert) and therefore unacceptable.

[0265] In the following examples, the amounts of the ingredients shown are weight percentages. For oil phase compositions, the ingredients shown are weight percentages of the oil phase composition. For water phase compositions, the ingredients shown are weight percentages of the water phase composition. For emulsion compositions, the ingredients shown are weight percentages of the emulsion composition. For the weight ratio of WP (water phase) to OP (oil phase), the ratio shown is the weight ratio based on the final emulsion weight.

[0266] Example 1: Effect of Water Phase (WP): Oil Phase (OP) Weight Ratio

[0267]

[0268]

[0269] Examples 1.A, 1.B and 1.C, where the water phase to oil ratio ranged from 94:6 to 70:30, formed water-in-oil emulsions with suitable physical properties after static freezing, as shown by being scoopable at -12° C. and -18° C. In contrast, Example 1.1, where the water phase to oil ratio was 96:4, did not form the desired emulsion.

[0270] Example 2: Effect of HLB of Emulsifier

[0271]

[0272]

[0273]

[0274]

[0275] Examples 2.A, 2.B, 2.C and 2.D, which contain emulsifiers with an HLB of 0.1 to 5, form water-in-oil emulsions that have suitable physical properties after static freezing, as shown by being scoopable at -12° C. and -18° C. In contrast, Examples 2.1 and 2.2, which contain emulsifiers with an HLB greater than 5, do not form the desired emulsions.

[0276] Example 3: Effect of emulsifier concentration

[0277]

[0278]

[0279] Examples 3.A, 3.B, 3.C and 3.D form water-in-oil emulsions that have suitable physical properties after static freezing, as shown by being scoopable at -12°C and -18°C. It can also be seen that for these examples, the emulsions contain at least (W×A) wt% of emulsifier based on the weight of the emulsion, where W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion; and A is at least 0.0001.

[0280] Example 4: Effect of Oil Concentration in Oil Phase

[0281]

[0282]

[0283] Examples 4.A, 4.B and 4.C, wherein the oil phase contained at least 91 wt% edible oil, formed water-in-oil emulsions that had suitable physical properties after static freezing, as shown by scoopability at -12°C and -18°C.

[0284] Example 5

[0285] The effect of the melting point of the oil relative to the melting point of the precursor aqueous phase is evaluated in the following examples. In the following table, the temperature at which the edible oil contains 25 wt% solid fat is determined using DSC as described above and the temperature at which the aqueous phase contains 25 wt% ice is determined by calculation according to the art.

[0286]

[0287]

[0288] Examples 5.A and 5.B, where the temperature at which the edible oil contained 25 wt% solid fat was lower than the temperature at which the aqueous phase contained 25 wt% ice, formed water-in-oil emulsions that had suitable physical properties after static freezing (i.e., scoopable at -12°C and -18°C). Example 5.1 used an edible oil (olive oil) containing 25 wt% solid fat at a temperature higher than the temperature at which the aqueous phase contained 25% ice. Although Example 5.1 initially formed a water-in-oil emulsion, it did not have suitable physical properties after static freezing.

[0289] Example 6: Effect of the presence of a structurant in the oil phase

[0290]

[0291]

[0292] Examples 6.A (no fat structurant) and 6.B (3.61 wt% fat structurant, based on the weight of the oil phase) both formed water-in-oil emulsions that had suitable physical properties after static freezing, as shown by scooping at -12°C and -18°C.

[0293] Example 7: Effect of the amount of water in the aqueous phase

[0294]

[0295] Examples 7.A and 7.B containing 45-96 wt% water (based on the weight of the precursor aqueous phase) formed water-in-oil emulsions that had suitable physical properties after static freezing, as shown by being scoopable at -12°C and -18°C.

[0296] Example 8: Effect of the amount of freezing point depressant

[0297]

[0298]

[0299]

[0300] Examples 8.A, 8.B, 8.C, and 8.D contained 2.5-40 wt% sucrose (based on the weight of the emulsion) and formed water-in-oil emulsions that had suitable physical properties after static freezing, as shown by being scoopable at -12° C. and -18° C. In contrast, although Examples 8.1 and 8.2 formed water-in-oil emulsions, they did not have suitable physical properties after static freezing.

[0301] Example 9: Effect of the presence of a structurant in the aqueous phase

[0302]

[0303]

[0304] Example 9.A (1.36 wt% tapioca starch + 0.21 wt% Iota carrageenan) formed a water-in-oil emulsion that had suitable physical properties after static freezing, as shown by being scoopable at -12°C and -18°C.

[0305] Example 10: Effect of the presence of a nucleating agent in the aqueous phase

[0306]

[0307]

[0308]

[0309]

[0310] Examples 10.A, 10.B, 10.C and 10.D formed water-in-oil emulsions that had suitable physical properties after static freezing (scoopable at -12°C and -18°C). While Example 10.1 also formed a water-in-oil emulsion, it did not have the desired texture due to the high level of nucleating agent. Thus, while the presence of nucleating agents is optional, when present they should constitute no more than 10 wt% of the weight of the emulsion.

[0311] Example 11: Effect of Aeration and the Presence of Air Stabilizer

[0312]

[0313] Examples 11.A, 11.B and 11.C formed water-in-oil emulsions that had suitable physical properties after static freezing, as shown by being scoopable at -12°C and -18°C, thereby demonstrating that the aeration system worked well with or without the presence of an air stabilizer.

[0314] Part B - Sensory Evaluation

[0315] In the following examples, half of the samples were subjected to a temperature abuse cycle representative of the quality of the product market after transportation and retail. The temperature abuse was a cycle of 1 hour at -18°C, then 4 hours at -6°C, repeated over a period of 75 hours (15 cycles, using a programmable environmental test chamber: manufacturer ACS, model DY340). The sample size was a 60g portion. This method allows for an indirect assessment of microstructural stability through sensory analysis, ideally with minimal / undetectable differences in textural properties when comparing temperature abused samples to non-abused samples.

[0316] After the abuse cycle, samples were placed at -18°C or -12°C for at least 24 hours before consumption. A structured group evaluation was conducted in which 8-10 participants compared the textural properties (firmness to spoon, hardness, iciness) of paired samples before and after temperature abuse. Samples were randomly coded and participants were blinded to the formulation and whether the sample had been thermally abused. Participants were also asked whether the sample would be considered "acceptable" as a product recommendation.

[0317] Example 12 - Non-aerated Example

[0318]

[0319]

[0320] Example 12.A was very stable, showed no structural changes after abuse, and was considered acceptable by participants when supplied at -12°C.

[0321] Example 12.B was stable with some limited softening of texture which was not considered detrimental by the participants. The product was considered smooth and 87.5% of the participants found the sample acceptable when served at -18°C.

[0322] Example 12.C was stable and surprisingly less refreshing after temperature abuse. When served at -12°C, the sample was considered acceptable by the participants.

[0323] Example 12.D was very stable with no significant structural changes and was considered acceptable by participants when served at -12°C.

[0324] Example 12.E was stable with some limited but acceptable texture softening after abuse, and all participants found the sample to be acceptable at -18°C.

[0325]

[0326]

[0327] Example 12.F was stable with some limited but acceptable texture softening after abuse.Despite the high oil content (75 wt% oil phase: 25 wt% water phase), the majority of participants considered the sample acceptable.

[0328] Example 12.G was stable with only very minor changes in texture attributes after abuse. Although softer and sweeter due to the high sucrose content, all participants found the texture to be acceptable.

[0329] The weight ratio of water phase to oil phase for Example 12.1 was 96:4, and the phase was converted to a water continuous system, and the conductivity (0.94 mS / cm) was recorded. In view of this failure, this example was not further analyzed.

[0330] Example 12.2 contained less than 4 wt% (based on the weight of the emulsion) of freezing point depressant. Although the samples were stable with no structural changes after abuse, all participants found the samples to be unacceptably hard and unable to separate when served at -18°C or -12°C.

[0331] Example 13 - Inflatable Example

[0332]

[0333]

[0334] These examples, when aerated with or without additional air stabilizer, were found to provide a softer and lighter sensory experience relative to the un-aerated systems.

[0335] Example 13.A Very stable with no structural changes after abuse. The product was considered soft and smooth and all participants found the product acceptable at -18°C.

[0336] Example 13.B experienced some structural changes after temperature abuse, becoming slightly stiffer, but in both cases the product had acceptable firmness. All participants considered the sample to be acceptable at -18°C.

[0337] Example 13.C was stable, with some softening of texture after temperature abuse, and a slightly crumbly but acceptable consistency. 90% of participants considered the sample acceptable at -18°C.

[0338] Part C - Evaluation of prior art document JP64063341

[0339] In Example 1 of JP64063341, a quantity of diacylglycerol containing 100 g of diacylglyceride as oil / emulsifier was prepared and mixed with 500 g of aqueous phase containing 20 wt% sucrose in water to obtain a w / o emulsion which was frozen into a frozen dessert. Example 1 of JP64063341 was repeated using diacylglyceride (DAG), Econa oil as oil. The description of Example 1 of JP64063341 was implemented as follows.

[0340] Material

[0341] Econa oil: contains 80 wt% diacylglycerides and 20 wt% triacylglycerides (Kao, Tokyo, Japan); Oil composition:

[0342] -57% polyunsaturated fatty acids,

[0343] -36% monounsaturated fatty acids,

[0344] -7% saturated fatty acids.

[0345] Sucrose: Finely crystalline solid sugar.

[0346] Water: laboratory deionized water

[0347] formula

[0348] 125g Econa oil

[0349] 100 g sucrose

[0350] 400 g deionized water

[0351] According to the method of JP64063341:

[0352] A commercially available lipase preparation (manufactured by Novo Industry AS) (10 g), 100 g of rapeseed oil and 10 g of glycerol were mixed, then stirred and mixed with 100 g of rapeseed oil and 10 g of glycerol (containing 0.8% of water) at 80° C., and the resulting mixture was stirred and reacted at 80° C. for 15 hours. The following table shows the glyceride composition in the reaction product.

[0353] Triglycerides Diacylceride Monoglyceride 11.2 wt% 60.0% by weight 28.8 wt%

[0354] A 20% sucrose aqueous solution (500 g) was added to 100 g of the glycerol dirapeseed oil fatty acid ester produced in Production Example 1, followed by stirring for 5 minutes using a whipping device to attempt to prepare a water-in-oil emulsion. The resulting emulsion was immediately stored in a refrigerator at -20°C for 12 hours to obtain a water-in-oil frozen dessert.

[0355] This method results in poor emulsification: a two-phase product is obtained with a foamy and a clear "emulsion" phase. The conductivity measurements vary between zero and below zero, but such measurements are difficult to make due to the two-phase product obtained which results in an oily coating on the sensor contacts. When frozen, the product is unacceptable and inedible. This indicates that the teaching of JP64063341 does not provide an acceptable frozen dessert.

[0356] Subsequent experiments were performed using the same recipe, but with an alternative approach where the aqueous phase was added slowly in small steps. Used for Another way to repeat JP64063341

[0357] 50 g of sucrose was dissolved in 200 ml of deionized water at room temperature to obtain an aqueous phase. 250 g of the aqueous phase was added to 62.5 g of Econa oil (containing 80 wt %, e.g. 50 g of DAG). In a Kenwood Chef Major (induction assisted heater / mixer), the contents were stirred at speed 6 for 5 minutes with a whipping device (Kenwood balloon whipper) to prepare a W / O emulsion at room temperature.

[0358] The emulsion was immediately stored in the form of 35 ml small samples in plastic cups in a Weiss SB22 climatic chamber operated as a blast freezer to obtain a frozen dessert at -18°C.

[0359] The result was a white water-in-oil emulsion product with zero conductivity and 20% oil phase. The product was oil continuous and stable over a period of 3 days. However, when the product was statically frozen, it resulted in a hard product that could not be scooped out with a spoon at -18°C. Also, when this product form was consumed by trained panelists, its taste was found to be unacceptable for a frozen dessert (fishy taste).

Claims

1. A water-in-oil emulsion for preparing frozen desserts, the emulsion comprising an aqueous phase WP and an oil phase OP in a weight ratio WP:OP of 94:6 to 70:30, wherein: - the oil phase comprises at least edible oil and an emulsifier, and the average HLB of the emulsifier is 0.1-5; - the aqueous phase comprises at least water, one or more freezing point depressants and one or more thickeners; - the emulsion comprises at least (W×A) wt% of an emulsifier based on the weight of the emulsion, wherein: W is the proportion of the aqueous phase in the emulsion, expressed as a weight percentage of the total emulsion; and A is 0.0001; - the emulsion comprises up to (0×0.2) wt% of an emulsifier based on the weight of the emulsion, wherein: O is the proportion of the oil phase in the emulsion, expressed as a weight percentage of the total emulsion; - the emulsion comprises 4-40 wt% of one or more freezing point depressants based on the weight of the emulsion; and - the temperature at which the edible oil contains 25 wt% of solid fats relative to the weight of the edible oil is lower than the temperature at which the aqueous phase contains 25 wt% of ice relative to the weight of the aqueous phase.

2. The water-in-oil emulsion according to claim 1, wherein the weight ratio of water phase to oil phase WP:OP is at most 90:

10.

3. The water-in-oil emulsion according to claim 1, wherein the edible oil is selected from the group consisting of corn seed oil, grape seed oil, linseed oil, sunflower seed oil, rapeseed oil, walnut oil or a combination thereof.

4. The water-in-oil emulsion according to any one of claims 1 to 3, wherein the temperature at which the edible oil contains 25 wt% solid fat is at least 4°C lower than the temperature at which the aqueous phase contains 25 wt% ice.

5. The water-in-oil emulsion according to claim 1, wherein the average HLB of the emulsifier is 0.25-4.

6. The water-in-oil emulsion according to claim 1, wherein the emulsifier is selected from the group consisting of glycerol fatty acid esters, polyglycerol esters of fatty acids, sorbitan esters of fatty acids, propylene glycol esters of fatty acids, sucrose esters of fatty acids, polyglycerol ricinoleate, lecithin and egg yolk, or a mixture thereof.

7. The water-in-oil emulsion according to claim 1, wherein the emulsifier is an organic acid ester of monoglyceride.

8. The water-in-oil emulsion of claim 1, wherein the emulsion comprises the one or more freezing point depressants in an amount of at least 5 wt% based on the weight of the emulsion.

9. The water-in-oil emulsion according to claim 1, wherein the one or more freezing point depressants are selected from sugars, salts or sugar alcohols or mixtures thereof.

10. The method for preparing the water-in-oil emulsion according to claim 1, comprising the following steps: -Preparing a precursor aqueous phase comprising: 45-96 wt % of water by weight of the precursor aqueous phase; One or more freezing point depressants in an amount of 4-40 wt % based on the weight of the precursor aqueous phase; one or more thickeners; -Preparation of a precursor oil phase comprising: 90-97.9 wt% of the precursor oil phase in an amount of edible oil; and An emulsifier in an amount of 0.05-20 wt% of the precursor oil phase, wherein the average HLB of the emulsifier is 0.1-5, wherein the temperature at which the edible oil contains 25 wt% of solid fat accounting for the weight of the edible oil is lower than the temperature at which the water phase contains 25 wt% of ice accounting for the weight of the water phase; - mixing the precursor water phase with the precursor oil phase to form the water-in-oil emulsion, wherein the weight ratio of the water phase WP to the oil phase OP of the obtained water-in-oil emulsion is 94:6 to 70:30; The emulsification step is carried out at a temperature higher than the melting point of the aqueous phase of the precursor.

11. The method of claim 10, wherein the precursor oil phase comprises at least 91 wt% of the edible oil based on the weight of the precursor oil phase.

12. The method of claim 10, wherein the precursor oil phase comprises at least 0.1 wt% of the emulsifier based on the weight of the precursor oil phase.

13. The method according to any one of claims 10 to 12, wherein the precursor oil phase comprises a fat structurant, wherein the fat structurant refers to a fat whose melting point is higher than the melting point of edible oil and also higher than the temperature at which the water-in-oil emulsion is prepared, and the emulsification step is carried out at a temperature higher than the melting point of the precursor water phase and lower than the melting point of the fat structurant.

14. Process for the preparation of a frozen dessert, wherein the water-in-oil emulsion according to any one of claims 1 to 9 is statically frozen.

15. A frozen dessert comprising the water-in-oil emulsion according to any one of claims 1 to 9.

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