Method of storing concentrated frozen confection premix

Abstract

The present invention relates to a method of storing a concentrated frozen confection premix wherein the concentrated premix is an oil-in-water emulsion in liquid form, the oil-in-water emulsion comprising: fat in an amount of from 8 wt% to 20 wt%; a sugar in an amount of 40 wt% to 64 wt%; a protein in an amount of 1.5 wt% to 14 wt%; and water in an amount of 16 wt% to 36 wt%. The method comprises storing the concentrated premix in a closed container for a shelf life of up to 84 days, wherein the concentrated premix: is not subjected to more than 3 days for a temperature of more than 37 DEG C during the shelf life; and is not subjected to a temperature of more than 6 days to less than 6 DEG C during the shelf life.

Description

Technical Field

[0001] The present invention relates to concentrated premixes for preparing frozen desserts; in particular to a method for storing such concentrated premixes. The concentrated premixes are oil-in-water emulsions having a high total solids content. Background Art

[0002] The preparation of frozen desserts, such as ice cream, is an energy-intensive process that generally includes several stages, namely: mix preparation (consisting of feeding and mixing the ingredients); pasteurization and homogenization; aging; freezing and hardening. Each of these stages requires energy.

[0003] The production of frozen desserts with sought-after organoleptic properties involves emulsifying the fat in the premix so that it is in the form of very small droplets. This is usually achieved using homogenization equipment, most commonly a valve homogenizer, in which the mixture is forced through a small valve under high pressure. Therefore, the efficiency with which the homogenization equipment is used is an important factor affecting the total energy consumption of the production process.

[0004] The method described in WO 2016 / 116336 aims to improve the efficiency of the use of homogenization equipment. This is achieved by a split stream process, in which an emulsion with a high fat content is prepared and then diluted with an additive composition and an aqueous liquid to form a premix. In order to be able to store for a longer time and / or transport over longer distances, the additive composition is granulated together with the concentrated emulsion as a binder. Such granules are said to be much more stable than liquid emulsions. However, in addition to the energy input required to dry the granules to the appropriate moisture content, the drying step may introduce undesirable off-flavors.

[0005] It would therefore be desirable to provide a concentrated premix in liquid form as this would avoid the energy input and attendant off-flavor development associated with producing / drying the granules.

[0006] Storage of concentrated oil-in-water emulsions in liquid form is not simple. First, the coalescence of oil droplets must be controlled, because small oil droplets are necessary to produce the desired organoleptic properties in the final frozen dessert. In addition, the Maillard reaction needs to be controlled. The Maillard reaction is known to affect food quality parameters, including sensory properties. For some foods (such as dairy products), the changes caused by the Maillard reaction are generally unwelcome-for example, the products of the Maillard reaction may be considered as off-flavors. The later stages of the Maillard reaction include the formation of advanced glycation end products (AGEs) and melanoidins, which can cause color changes, affect sensory properties, and in some cases affect shelf life. Elevated temperatures (such as those used during sterilization or UHT treatment) can significantly enhance the formation of AGEs and melanoidins, and AGEs and melanoidins are known to accumulate during long-term storage or transportation. Therefore, it is important to be able to control the Maillard reaction during food production and storage. The rate of the Maillard reaction may be affected by several factors, including but not limited to the type of reactants, temperature / time combination, water activity and pH.

[0007] We have found that storage conditions need to be carefully controlled to prevent concentrated emulsions from becoming unstable. It is particularly important to control the storage temperature over time. SUMMARY OF THE INVENTION

[0009] The present invention relates to a method of storing a concentrated frozen dessert premix, wherein the method comprises storing the concentrated premix in a sealed container for a storage period of up to 84 days,

[0010] wherein the concentrated premix is ​​an oil-in-water emulsion in liquid form, the oil-in-water emulsion comprising: fat in an amount of 8 wt% to 20 wt%; sugar in an amount of 40 wt% to 64 wt%; protein in an amount of 1.5 wt% to 14 wt%; and water in an amount of 16 wt% to 36 wt%;

[0011] and wherein the concentrated premix:

[0012] Not subjected to temperatures exceeding 37°C for more than 3 days during the storage period; and

[0013] Do not be subjected to temperatures below 6°C for more than 6 days during storage. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention relates to a method for storing a concentrated frozen dessert premix. A concentrated frozen dessert premix (referred to herein as a "concentrated premix" for brevity) is an oil-in-water emulsion in liquid form with a high total solids content. The concentrated premix can be simply diluted with an aqueous liquid to produce a premix containing all ingredients in appropriate proportions. In addition, the premix can be tailored during the dilution step, for example by adding a small amount of flavoring and / or coloring.

[0016] The concentrated premix is ​​an oil-in-water emulsion comprising fat in an amount of 8 to 20 wt %, sugar in an amount of 40 to 64 wt %, protein in an amount of 1.5 to 14 wt %; and water in an amount of 16 to 36 wt %.

[0017] The method comprises storing the concentrated premix in a sealed container for a storage period of up to 84 days. The sealed container helps to prevent the concentrated premix from being contaminated by microorganisms during storage. If the temperature is controlled according to the limits of the present invention, the concentrated premix remains stable during the storage period. Preferably, the storage period is up to 70 days, up to 56 days, up to 42 days, up to 35 days, up to 28 days or even up to 21 days. The storage period is preferably at least 1 day, at least 5 days, at least 7 days, at least 10 days or even at least 14 days.

[0018] The concentrated premix may be maintained at one location during the storage period, or it may be transported between locations (eg, from a production plant to a finishing plant) during at least a portion of the storage period.

[0019] To prevent the Maillard reaction, which may lead to undesirable color changes and impair the organoleptic properties, the concentrated premix is ​​not subjected to a temperature exceeding 37° C. for more than 3 days during the storage period. Preferably, the concentrated premix is ​​not subjected to a temperature exceeding 37° C. for more than 2 days during the storage period, more preferably, the concentrated premix is ​​not subjected to a temperature exceeding 37° C. for more than 1 day during the storage period.

[0020] Preferably, the concentrated premix is ​​not subjected to a temperature exceeding 35° C. for more than 12 days during said storage period. More preferably, the concentrated premix is ​​not subjected to a temperature exceeding 35° C. for more than 6 days during said storage period, and most preferably, the concentrated premix is ​​not subjected to a temperature exceeding 35° C. for more than 3 days during said storage period.

[0021] Preferably, the concentrated premix is ​​not subjected to a temperature exceeding 30° C. for more than 21 days during said storage period. More preferably, the concentrated premix is ​​not subjected to a temperature exceeding 30° C. for more than 14 days during said storage period, and most preferably, the concentrated premix is ​​not subjected to a temperature exceeding 30° C. for more than 7 days during said storage period.

[0022] We surprisingly found that storage of the concentrated premix at low temperatures promotes coalescence of the oil droplets, which in turn affects the organoleptic properties of the final frozen dessert. In order to limit coalescence of the oil droplets, the concentrated premix is ​​not subjected to a temperature below 6°C for more than 6 days during the storage period. Preferably, the concentrated premix is ​​not subjected to a temperature below 6°C for more than 4 days during the storage period, more preferably, the concentrated premix is ​​not subjected to a temperature below 6°C for more than 2 days during the storage period.

[0023] Preferably, the concentrated premix is ​​not subjected to a temperature below 10° C. for more than 28 days during the storage period. More preferably, the concentrated premix is ​​not subjected to a temperature below 10° C. for more than 21 days during the storage period, and most preferably, the concentrated premix is ​​not subjected to a temperature below 10° C. for more than 14 days during the storage period.

[0024] Preferably, the concentrated premix has an average temperature of 6°C to 37°C, more preferably 8°C to 35°C, 10°C to 30°C, or even 12°C to 27°C, averaged over said storage period.

[0025] In order to further control the extent of the Maillard reaction and / or inhibit the growth of microorganisms, the water activity of the concentrated premix is ​​preferably no more than 0.84, for example 0.70 to 0.84. Additionally or alternatively, the pH of the concentrated premix is ​​preferably 5 to 8.

[0026] The concentrated premix only needs to be diluted with an aqueous liquid (such as water) to produce a premix for frozen desserts. Therefore, the concentrated premix contains fat in an amount of 8wt% to 20wt%, preferably 9wt% to 19wt%, 10wt% to 18wt%, or even 11wt% to 17wt%. The fat is preferably milk fat (such as butter fat) or vegetable fat (such as coconut oil, palm oil, palm kernel oil or a mixture thereof). Preferably, the fat is vegetable fat, and particularly preferably, the fat is coconut oil.

[0027] High concentration of sugar may bring undesirable sweetness and / or heat to the frozen dessert (after dilution and freezing) finally prepared by the concentrated premix. On the contrary, if the frozen dessert finally prepared by the concentrated premix is ​​a scoopable product, low concentration of sugar may be inappropriate because low concentration of sugar tends to cause the frozen dessert to have high ice content. Therefore, the concentrated premix comprises the sugar of the amount of 40wt% to 64wt%, and preferably comprises the sugar of the amount of 42wt% to 62wt%, 44wt% to 60wt% or even 46wt% to 58wt%. As used herein, the term "sugar" includes monosaccharides, disaccharides and oligosaccharides (formed by 3 to 10 monosaccharide units). Monosaccharides include glucose, fructose, galactose and mannose. Disaccharides include sucrose, lactose and trehalose. Oligosaccharides include raffinose. The term "sugar" does not include polysaccharides comprising>10 monosaccharides. Some ingredients usually included in frozen desserts may increase the amount of sugar. An example is corn syrup (sometimes called glucose syrup) - a mixture of mono-, disaccharides, and oligosaccharides.

[0028] The concentrated premix comprises protein in an amount of 1.5 to 14 wt%, and preferably 1.6 to 12 wt%, 1.7 to 10 wt%, 1.8 to 8 wt% or even 1.9 to 6 wt%.Preferably, the protein is milk protein or vegetable protein, or a mixture thereof.

[0029] If the emulsion becomes too concentrated, it may become difficult to handle in subsequent processing, in particular it may become difficult to pump. On the other hand, low water activity may mean that the concentrated premix has a longer shelf life. The concentrated premix contains water in an amount of 16wt% to 36wt%. Preferably, the concentrated premix contains water in an amount of at least 17wt%, at least 18wt% or at least 19wt%. Preferably, the concentrated premix contains water in an amount of no more than 32wt%, no more than 29wt%, no more than 28wt%, no more than 27wt% or even no more than 26wt%. The concentrated premix of the present invention has a high total solid content. The total solid content is the sum of all ingredients except water. Since the concentrated premix contains water in an amount of 16wt% to 36wt%, the total solid content of the concentrated premix is ​​64wt% to 84wt%. The total solid content of the concentrated premix affects the viscosity, and the higher the total solids, the higher the viscosity. This may be advantageous because higher viscosity is associated with better oil droplet breakage. However, the energy input required to achieve the emulsification of the oil also increases with increasing viscosity, and at very high viscosities there is a risk of overloading the emulsifying equipment. Therefore, it is necessary to balance these competing technical considerations. Preferably, the total solids content of the concentrated premix is ​​at least 68wt%, at least 71wt%, at least 72wt%, at least 73wt% or at least 74wt%. Preferably, the total solids content of the premix is ​​no more than 83wt%, no more than 82wt%, or no more than 81wt%.

[0030] The concentrated premix preferably includes a stabilizer in the amount of 0.3wt% to 3wt% and / or an emulsifier in the amount of 0.1wt% to 2wt%. Preferably, the concentrated premix includes a stabilizer in the amount of 0.2wt% to 2wt%, 0.4wt% to 1.5wt% or even 0.6wt% to 1.0wt%. Stabilizer is preferably selected from: alginate (E400-E405), carrageenan (E407), locust bean gum (E410), guar gum (E412), xanthan gum (E415), tara gum (E417), pectin (E440), sodium carboxymethylcellulose (E466) and mixtures thereof. Preferably, the concentrated premix includes an emulsifier in the amount of 0.2wt% to 1.5wt%, 0.3wt% to 1.2wt% or even 0.4wt% to 1.0wt%. A single emulsifier or a mixture of emulsifiers can be used. For example, mono / diglycerides (E471), which are commonly used as emulsifiers in frozen desserts.

[0031] The concentrated premixes of the present invention may be susceptible to microbial spoilage. A common method for limiting such spoilage is refrigeration. However, this is not suitable for the concentrated premixes of the present invention because it has unexpectedly been found to promote the coalescence of oil droplets. Therefore, it may be appropriate to inhibit spoilage microorganisms using different methods. Therefore, the concentrated premix is ​​preferably subjected to a sterilization step (such as pasteurization) before storage. After such a sterilization step, the method may include aseptically feeding the concentrated premix into a container before closing the container, and storing the concentrated premix for the storage period. If a longer shelf life (i.e., several weeks) is required, this step is most likely to be suitable. However, in practice, this step is generally not required. In fact, it is preferred that the concentrated premix is ​​fed into the container after the sterilization step before cooling (commonly referred to as "hot filling").

[0032] The concentrated premix may optionally include a preservative. If a long shelf life of several weeks is required, adding a preservative may be appropriate, and a cheaper and / or more convenient alternative to aseptic feeding of the concentrated premix can be provided. The concentrated premix preferably includes 0.02wt% to 0.5wt% of a preservative, and the preservative is preferably sorbic acid (E200) or a salt thereof. Suitable salts include sodium sorbate (E201), potassium sorbate (E202) and calcium sorbate (E203). Successful preservatives inhibit spoilage microorganisms without interfering with the organoleptic properties of the final frozen dessert product. It should be noted that the preservative level in the concentrated premix is ​​not the preservative level in the final frozen dessert product, because the concentrated premix is ​​diluted before being used to prepare frozen desserts. This means that a relatively high level of preservative can be added to the concentrated premix without compromising the organoleptic properties of the final frozen dessert. However, it is preferred that the level of the preservative is kept as low as possible while still comprising an amount sufficient to inhibit spoilage microorganisms. Thus, the concentrated premix preferably comprises the preservative in an amount of 0.02 wt% to 0.5 wt%, 0.06 wt% to 0.4 wt%, 0.1 wt% to 0.3 wt% or even 0.12 wt% to 0.2 wt%.

[0033] The method includes storing the concentrated premix in a closed container. The concentrated premix can be stored in any suitable container. Non-limiting examples of possible containers include pouches, tanks, bottles, kegs, barrels, drums, jerry cans, and intermediate bulk containers (IBCs). The volume of the container is preferably at least 500 ml, more preferably 1 L to 2000 L. In particular, the container is preferably a rigid or flexible intermediate bulk container with a capacity of at most 2000 L, preferably 250 L to 2000 L.

[0034] The advantage of a concentrated premix is ​​that it can be transported to a remote location during storage and then simply diluted with an aqueous liquid (preferably water) at the remote location and then frozen in a conventional manner to produce a high quality frozen confection at a finishing plant. This means that the finishing plant does not need to be equipped with mixing equipment capable of handling and mixing multiple ingredients.

[0035] In the case where the concentrated premix is ​​to be transported between different locations (e.g. from a hub factory to a finishing plant), the container is preferably an intermediate bulk container (preferably having a volume of 250L to 2000L) or a tanker truck (preferably having a volume of 10000L to 44000L). A tanker truck typically comprises a cylindrical tank placed on a vehicle body in a substantially horizontal manner. The tank typically comprises a plurality of compartments and / or baffles to prevent the load from shifting during transport and destabilizing the vehicle. The tanker truck should be suitable for transporting food grade materials and is typically equipped with a pumping system to allow loading and unloading of liquid loads.

[0036] It may also be included that the concentrated premix may be transported to a retail store rather than a factory. For example, this may occur in the case where the concentrated premix is ​​used for a soft-serve ice cream product. Such products are made in a small ice cream freezer, such as in an ice cream truck or cafe, and may be eaten immediately. Therefore, the container may be relatively small, and preferably a bottle or bag having a volume of 500 ml to 50 L, more preferably 500 ml to 10 L, or even 500 ml to 2 L.

[0037] Preferably, a diluent is added to the concentrated premix at the end of the storage period. The diluent is an aqueous liquid, preferably water. The ratio of the concentrated premix to the diluent is preferably 1:1 to 1:3.

[0038] The dilution step provides a premix which can be frozen to produce a frozen dessert. The premix can be adjusted during the dilution step by adding small amounts of flavours and / or colours.

[0039] Unless otherwise indicated, numerical ranges expressed in the format "from x to y" should be understood to include x and y, and when specifying any range of values ​​or amounts, any particular upper value or amount can be associated with any particular lower value or amount.

[0040] Except in the examples and comparative experiments, or where otherwise expressly indicated, all numbers are understood to be modified by the word "about". As used herein, unless otherwise indicated, the indefinite article "a / an" and the corresponding definite article "the" mean at least one or one or more.

[0041] Attached photos

[0042] By way of example, the present invention is described with reference to the following drawings, in which:

[0043] Figure 1 is a graph of oil droplet size data from Example 1;

[0044] Figure 2a and 2b This is the color change data diagram of Example 1. Example

[0045] The examples are intended to illustrate the invention, but the invention is not limited to these examples per se.

[0046] Example 1

[0047] Preparation of concentrated premixes

[0048] A concentrated premix having the formulation shown in Table 1 was prepared. Briefly, the aqueous phase was prepared by adding hot water (80°C) to a mixing vessel followed by sucrose, stabilizer, corn syrup, fructose, glucose monohydrate, skim milk powder and whey protein concentrate. During the addition of the aqueous phase ingredients, the mixer was set to 3000 rpm and heated at 60°C to 75°C to ensure complete dissolution / dispersion of the ingredients. The oil phase was prepared by melting coconut oil and mixing it with an emulsifier. A concentrated oil-in-water emulsion was prepared by adding the oil phase to the aqueous phase and passing the mixture through a rotor-stator mixer set at 4200 rpm. The rotor diameter of the rotor-stator mixer was 0.145 m and the shear clearance was 0.5 mm. The concentrated premix was pasteurized.

[0049] Table 1: Concentrated premix formulation

[0050]

[0051]

[0052] Storage test

[0053] The concentrated premix was separated into containers and the containers were sealed. The containers were stored at a constant temperature of 5°C, 20°C, 25°C, 30°C, 35°C or 40°C for a period of 84 days. The coalescence of oil droplets was investigated at 5°C or 20°C during a storage period of up to 28 days. The color change at different storage temperatures (20°C, 30°C, 35°C, 40°C) was investigated during a storage period of up to 21 days, and samples were analyzed regularly from the 3rd day of storage. In addition, microbial growth was investigated at 25°C (selected as the optimal temperature for yeast and mold growth); the concentrated premix did not deteriorate due to mold growth during the storage period of up to and including 84 days.

[0054] Oil droplet size

[0055] The effect of storage testing on the oil droplet size was determined. The oil droplet size was measured using a Malvern Mastersizer 3000 equipped with a wet dispersion unit to determine the surface weighted average droplet size (D 3,2 The premix samples were diluted 10-fold in a solution of sodium dodecyl sulfate (SDS) and urea (6.6 M urea, 0.1% SDS, pH 7) and sonicated at full power for 1 minute in a dispersion device before starting the particle size measurement. This treatment ensures that any weakly bound or flocculated oil droplets are separated into individual droplets to more accurately represent the droplet size (this treatment does not break up completely coalesced or aggregated droplets).

[0056] The effect of storage temperature on oil droplet size over time is as follows: Figure 1 The data in Figure 2 show that the dashed line represents storage at 20°C and the solid line represents storage at 5°C. The results show that when the concentrated premix is ​​stored at 20°C, the oil droplet size remains unchanged (less than 1 μm). In contrast, storage at 5°C causes the oil droplet size to increase significantly over time, indicating that the emulsion has coarsened. Although not included in Figure 1 However, when the concentrated premix was stored at 20°C (i.e., a storage period of at least 28 days), the oil droplet size remained constant for significantly longer than 15 days.

[0057] Color Analysis

[0058] The later stages of the Maillard reaction include the formation of advanced glycation end products (AGEs) and melanoidins, which can lead to color changes, affect sensory properties and, in some cases, shelf life. To assess the impact of the Maillard reaction on concentrated premixes, laboratory-based (LAB) color analysis was used to identify any color changes that occurred during storage trials.

[0059] The color and appearance of the samples were measured using a digital color imaging system (Digieye, VeriVede). The samples were photographed in a VeriVede cabinet under standardized D65 light without UV light, using a Nikon AF-SNikor with the lighting set to diffuse and without an internal mirror. The camera settings were as follows:

[0060] Camera zoom: 35mm,

[0061] Focus: Auto Focus,

[0062] Measurement mode: Diffuse Mode, D90 diffuse,

[0063] Chart type: Digitizer Chart V3.94,

[0064] Aperture: 8,

[0065] Shutter: 1 / 6.

[0066] Run the Calibration Wizard before taking measurements to ensure calibration consistency (maximum value <10, median value <1, RGB value = 210 ± 10). CIE76 color values ​​are generated from representative areas of sample photographs. The changes between the CIE76 color values ​​of the sample and the reference are reported independently and used to calculate the ΔE color change value, which ranges from 0 to 100. ΔE values ​​greater than 1 indicate that there is a perceptible color difference between the samples.

[0067] Figure 2a and 2b The data in show the color change over time for two different storage tests at storage temperatures of 20°C, 30°C, 35°C and 40°C. In both cases, the samples stored at 20°C showed almost no color change over time. In contrast, the samples stored at 40°C showed a noticeable color change even after a short period of time.

Claims

1. A method of storing a concentrated frozen dessert premix, wherein the method comprises storing the concentrated premix in a sealed container for a storage period of not longer than 84 days, wherein the concentrated premix is ​​an oil-in-water emulsion in liquid form, the oil-in-water emulsion comprising: fat in an amount of 8 wt% to 20 wt%; sugar in an amount of 40 wt% to 64 wt%; protein in an amount of 1.5 wt% to 14 wt%; and water in an amount of 16 wt% to 36 wt%; and wherein the concentrated premix: is not subjected to temperatures exceeding 37°C for more than 3 days during said storage period; and • Not subjected to temperatures below 6°C for more than 6 days during the storage period.

2. The method of claim 1, wherein the concentrated premix is ​​not subjected to a temperature exceeding 35°C for more than 12 days during the storage period.

3. A method according to claim 1 or claim 2, wherein the concentrated premix is ​​not subjected to a temperature exceeding 30°C for more than 21 days during the storage period.

4. The method according to any one of claims 1 to 3, wherein the concentrated premix is ​​not subjected to a temperature below 10°C for more than 28 days during the storage period.

5. The method according to any one of claims 1 to 4, wherein the concentrated premix has an average temperature of 6°C to 37°C on average during the storage period.

6. The method according to any one of claims 1 to 5, wherein the water activity of the concentrated premix is ​​not more than 0.84, preferably 0.70 to 0.

84.

7. The method according to any one of claims 1 to 6, wherein the pH of the concentrated premix is ​​from 5 to 8.

8. The method according to any one of claims 1 to 7, wherein the concentrated premix comprises a stabilizer in an amount of 0.3 wt% to 3 wt% and / or an emulsifier in an amount of 0.1 wt% to 2 wt%.

9. The method according to any one of claims 1 to 8, wherein the concentrated premix comprises 0.02 wt% to 0.5 wt% of a preservative, and the preservative is preferably sorbic acid or potassium sorbate.

10. The method according to any one of claims 1 to 9, wherein the concentrated premix is ​​subjected to a sterilization step before storage.

11. The method according to claim 10, wherein the method comprises aseptically feeding the concentrated premix into the container and storing the concentrated premix for the storage period before closing the container.

12. The method according to any one of claims 1 to 11, wherein the volume of the container is at least 500 mL, preferably 1 L to 2000 L.

13. The method according to any one of claims 1 to 12, wherein the container is a rigid or flexible intermediate bulk container with a volume of not more than 2000L, preferably 250L to 2000L.

14. The method according to any one of claims 1 to 13, wherein a diluent is added to the concentrated premix at the end of the storage period.

15. The method of claim 14, wherein the ratio of concentrated premix to diluent is 1:1 to 1:3.

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