OIL-IN-WATER EMULSION CONTAINING WHEAT FLOUR AND PHYSICALLY MODIFIED STARCH

Abstract

The present invention relates to a composition in the form of an oil-in-water emulsion, containing wheat flour and physically modified starch. The invention also relates to a method for preparation of the composition.

The invention further relates to the use of a wheat flour and physically modified starch to reduce syneresis in an oil-in-water emulsion.

Claims

1. A method for preparation of an oil-in-water emulsion wherein the method comprises the following steps: a) mixing water and wheat flour and physically modified starch at a temperature below 56° C.; b) heating the mixture from step a) from a temperature below 65° C. to a temperature ranging from 75° C. to 95° C., and keeping the mixture within that temperature range during a time period of at least 2 minutes; c) adding an acid to the mixture of step b), to a pH ranging from 3 to 5, d) adding oil to the mixture from step c) and dispersing the oil in the mixture; e) optionally homogenising the mixture of step d) to create an oil-in-water emulsion wherein the oil droplets have a surface weighted mean diameter D3,2 of less than 10 micrometer.

2. The method according to claim 1, wherein in the final optional homogenisation step the homogenisation is performed using a colloid mill operating at a rotation rate ranging from 2,000 to 14,000 rpm.

3. The method according to claim 1, wherein the mixture in step a) is mixed until homogenized.

4. The method according to claim 1, wherein the wheat flour is a native wheat flour.

5. The method according to claim 1, wherein the physically modified starch has been obtained by drying native starch to a relative humidity of less than 3%, and subsequently heating the starch at a temperature ranging from 150° C. to 200° C. during a time period of at least 30 minutes.

6. The method according to claim 1, wherein the physically modified starch comprises physically modified waxy corn starch.

7. The method according to claim 1, wherein the composition is an edible emulsion.

8. A method for preparation of an oil-in-water emulsion, comprising the steps of: a) mixing water and wheat flour at a temperature below 65° C., and heating the mixture to a temperature ranging from 75° C. to 95° C., and keeping the mixture within that temperature range during a time period of at least 2 minutes; and optionally subsequently cooling the mixture to a temperature below 70° C.; b) mixing water and physically modified starch at a temperature below 65° C., and heating the mixture to a temperature ranging from 75° C. to 95° C., and keeping the mixture within that temperature range during a time period of at least 2 minutes; and optionally subsequently cooling the mixture to a temperature below 70° C.; c) mixing the mixtures from steps a) and b) and optionally cooling the mixture to a temperature below 70° C.; d) adding an acid to the mixture of step c), to a pH ranging from 3 to 5, e) adding oil to the mixture from step d) and dispersing the oil in the mixture; f) optionally homogenising the mixture of step e) to create an oil-in-water emulsion wherein the oil droplets have a surface weighted mean diameter D3,2 of less than 10 micrometer.

9. The method according to claim 8, wherein steps a) and b) are performed simultaneously in two vessels or wherein steps a) and b) are performed in consecutive order.

10. the method according to claim 8, wherein in steps a) and b) the temperature of the mixture is increased from below 65° C. to a temperature ranging from 85° C. to 95° C.

Description

DESCRIPTION OF FIGURES

[0123] FIG. 1: Drawing of the stainless steel grid used for determining the Stevens value of oil-in-water emulsions as used herein. The grid has an outer size of about 3.7 cm by 3.7 cm. The grid contains 76 holes, each hole having a surface area of about 3×3 mm.

EXAMPLES

[0124] The following non-limiting examples illustrate the present invention.

[0125] Raw Materials [0126] Wheat flour: Wheat Flour T450 native undried <15% AN ex Saalemühle Alsleben GmbH (Alsleben, Germany) [0127] Physically modified starch: Physically modified waxy corn starch Novation Prima 300 ex Ingredion Inc. (Westchester, Ill., USA). [0128] Sunflower oil ex Cargill (Amsterdam, The Netherlands). [0129] Egg yolk: enzyme modified liquid egg yolk (egg yolk treated with phospholipase A2, fragments are retained in the product); ex Bouwhuis Enthoven (Raalte, the Netherlands), contains 8% NaCl: [0130] Salt: NaCl suprasel ex Akzo Nobel (Amersfoort, Netherlands). [0131] Sugar: sucrose white sugar W4 ex Suiker Unie (Oud Gastel, Netherlands). [0132] Vinegar: 12% Branntweinessig ex Carl Kühne (Hamburg, Germany). [0133] EDTA: Dissolvine E-CA-10—Calcium disodium EDTA ex Akzo Nobel (Amersfoort, Netherlands). [0134] Lactic acid: Lactic acid 80 ex (Corbion Purac, Gorinchem, Netherlands). [0135] Vinegar: 12% Branntweinessig ex Carl Kühne (Hamburg, Germany). [0136] Lemon juice: concentrate 45° brix ex Döhler (Darmstadt, Germany). [0137] Beta-carotene: 30% FS ex (DSM, Heerlen, Netherlands). [0138] HM pectin: Grindsted Pectin AMD781 ex DuPont Danisco (Copenhagen, Denmark).

[0139] Methods

[0140] Thickness—Stevens value: the Stevens value is determined at 20° C. by using a Stevens LFRA Texture Analyser (ex Brookfield Viscometers Ltd., UK) with a maximum load/measuring range of 1000 grams, and applying a penetration test of 25 mm using a grid, at 2 mm per second penetration rate, in a cup having a diameter of 65 mm, that contains the emulsion; wherein the grid comprises square openings of approximately 3×3 mm, is made up of wire with a thickness of approximately 1 mm, and has a diameter of 40 mm. One end of a shaft is connected to the probe of the texture analyser, while the other end is connected to the middle of the grid. The grid is positioned on the flat upper surface of the emulsion in the cup. Upon starting the penetration test, the grid is slowly pushed downward into the emulsion by the texture analyser. The final force exerted on the probe is recorded and translated into the Stevens value in gram. A drawing of the grid is given in FIG. 1. The grid is made from stainless steel, and has 76 holes, each hole having a surface area of approximately 3×3 mm. The data presented in Table 3 are the average of duplicate measurements.

[0141] Syneresis: Syneresis in an oil-in-water emulsion is the expelling of aqueous liquid, which separates from the product during storage after disrupting the structure by e.g. spooning. In this test gravimetric drip of expelled water from an oil-in-water emulsion into an acrylic cylinder is determined during a storage period at various climate conditions.

[0142] Materials: Acrylic cylinder (length 45 mm, inner diameter 21 mm, wall thickness 2 mm, open at two ends) and qualitative filter paper, type 415, diameter 75mm (ex VWR, Amsterdam, Netherlands). The filter is applied at one end of the cylinder and attached to the outside cylinder wall by adhesive tape. The tube with filter is vertically inserted into an emulsion sample of 225 mL in a jar, until the top of the cylinder is at level with the emulsion surface. The jar is closed with a lid, and stored at 5° C. or 20° C. The amount of liquid in the tube after storage is determined by taking out the liquid from the tube (which has passed through the filter into the tube) with a pipette, and weighing the amount of liquid (in gram) after a determined amount of time. The lower the syneresis value, the better the stability of the emulsion. The data presented in here are the averages of duplicate measurements.

[0143] Oil Droplet Size Measurement

[0144] The oil droplet size is determined using a Mastersizer 2000 E (ex Malvern Instruments Ltd., Malvern, UK) with accessory Hydro 2000 S (sample dispersion unit for aqueous suspensions). This device uses a method based on laser diffraction. The average droplet size is expressed as the D3,2, which is the surface weighted mean diameter of a set of droplets.

[0145] Rheology Measurements

[0146] Dynamic viscosity of emulsions is determined by using an AR1000 controlled stress rheometer ex TA Instruments (New Castle, Del., USA), operated at 50 s.sup.−1 and 20° C. During 1 minute an emulsion is subjected to a constant shear rate of 50 s.sup.−1. Every 10 seconds a measurement is made, and the measurement after 30 seconds is taken as the viscosity value and reported. Each product is measured at least twice.

[0147] Elastic modulus G′ is determined using the same rheometer. Oscillatory measurements are performed at 20° C. using a stainless steel cone-plate geometry (cone: 4 cm/2° and a truncation of 71 micrometer) at a frequency of 1 Hz in the stress interval from 0.01 Pa to 100 Pa (stress sweep). Each product to be measured at least twice. The G′ value is presented at 1% strain (1% deformation).

[0148] Equipment [0149] Mixed vessel: temperature controlled mixed vessel (Universal Machine UM-5, ex Stephan Machinery GmbH, Hameln, Germany); [0150] Colloid mill: MZM/VK-7 (Fryma-Maschinen AG, Rheinfelden, Switzerland).

Example 1. Preparation of Oil-In-Water Emulsions—Different Processes

[0151] In this example five oil-in-water emulsions were prepared, each having the same overall composition, nevertheless prepared using different processes, as specified below. The overall composition of the five emulsions is provided in Table 1.

TABLE-US-00001 TABLE 1 Composition of prepared oil-in-water emulsions. 314 315 316 317 318 Conc. Conc. Conc. Conc. Conc. Ingredient [wt %] [wt %] [wt %] [wt %] [wt %] Sunflower oil 49.4 49.4 49.4 49.4 49.4 Water 38.8 38.8 38.8 38.8 38.8 Egg yolk 3.8 3.8 3.8 3.8 3.8 Sugar 2.4 2.4 2.4 2.4 2.4 Wheat Flour 2.0 2.0 2.0 2.0 2.0 Physically modified 1.3 1.3 1.3 1.3 1.3 starch Vinegar 1.3 1.3 1.3 1.3 1.3 Salt 0.9 0.9 0.9 0.9 0.9 Lactic acid 0.1 0.1 0.1 0.1 0.1 Flavour 0.1 0.1 0.1 0.1 0.1 EDTA 0.008 0.008 0.008 0.008 0.008 Beta-carotene 0.005 0.005 0.005 0.005 0.005 Total* 100.0 100.0 100.0 100.0 100.0 *small differences may occur due to rounding of the numbers; in all tables in this specification

[0152] The emulsions are prepared by combining various phases, of which the composition is given in Table 2 for each of the emulsions.

TABLE-US-00002 TABLE 2 Detailed composition of oil-in-water emulsions from Table 1, relative amount of the phases in the recipes, and composition (in wt %) of each phase. 314 315 316 317 318 Conc. Conc. Conc. Conc. Conc. Phase [wt %] [wt %] [wt %] [wt %] [wt %] Water Phase 2.1 2.1 2.1 2.1 2.1 Wheat Flour Phase 2.0 2.0 25.2 25.2 0.0 Egg Phase 3.8 3.8 3.8 3.8 3.8 Oil Phase 49.5 49.5 49.5 49.5 49.5 Starch Phase 42.6 42.6 19.4 19.4 44.6 Water Phase Water 1.1 1.1 1.1 1.1 1.1 Salt 0.1 0.1 0.1 0.1 0.1 Vinegar 0.8 0.8 0.8 0.8 0.8 Lactic acid 0.1 0.1 0.1 0.1 0.1 Wheat Flour Phase Wheat Flour 2.0 2.0 2.0 2.0 0 Water 0.0 0.0 23.2 23.2 0 Egg phase Egg yolk 3.8 3.8 3.8 3.8 3.8 Oil Phase Sunflower oil 49.4 49.4 49.4 49.4 49.4 Flavour 0.1 0.1 0.1 0.1 0.1 Beta-carotene 0.005 0.005 0.005 0.005 0.005 Starch Phase Physically modified 1.3 1.3 1.3 1.3 1.3 starch Water 37.7 37.7 14.5 14.5 37.7 EDTA 0.008 0.008 0.008 0.008 0.008 Sugar 2.4 2.4 2.4 2.4 2.4 Vinegar 0.5 0.5 0.5 0.5 0.5 Salt 0.8 0.8 0.8 0.8 0.8 Wheat Flour 0 0 0 0 2.0

[0153] The processes applied to prepare these emulsions are the following.

[0154] Emulsion 314 (Comparative) [0155] 1. Starch phase is heated in a mixed vessel, 5 min. at 90° C. [0156] 2. This heated mixture is subjected to shear by pumping it through a high pressure homogeniser, operated at 0 bar, and cooled to 45° C. [0157] 3. Wheat flour phase (dry) is added to the mix, and heated in a Stephan pan, 5 min. at 90° C., and cooled to 65° C. [0158] 4. Starch phase, water phase, and egg phase are mixed using a colloid mill, and oil phase is added while recirculating.

[0159] Emulsion 315 (Comparative) [0160] 1. Starch phase is heated in a mixed vessel, 5 min. at 90° C., and cooled to 45° C. [0161] 2. Wheat flour (dry) is added to the mix and dispersed, and the complete mixture is heated in a Stephan pan, 5 min. at 90° C., and cooled to 65° C. [0162] 3. Starch phase, water phase, and egg phase are mixed using a colloid mill, and oil phase is added while recirculating.

[0163] Emulsion 316 [0164] 1. Starch phase (containing physically modified starch as the only starch source) is heated in a mixed vessel, 5 min. at 90° C., and cooled to 65° C. [0165] 2. Wheat flour phase is heated in a mixed vessel, 5 min. at 90° C., and cooled to 65° C. [0166] 3. Starch phase, wheat flour phase, water phase, and egg phase are mixed using a colloid mill, and oil phase is added while recirculating.

[0167] Emulsion 317 (Comparative) [0168] 1. Starch phase is heated in a mixed vessel, 5 min. at 90° C. [0169] 2. This heated mixture is subjected to shear by pumping it through a high pressure homogeniser, operated at 0 bar, and cooled to 65° C. [0170] 3. Wheat flour phase is heated in a mixed vessel, 5 min. at 90° C., and cooled to 65° C. [0171] 4. Starch phase, wheat flour phase, water phase, and egg phase are mixed using a colloid mill, and oil phase is added while recirculating.

[0172] Emulsion 318 [0173] 1. Starch phase (containing wheat flour and physically modified starch in this case) is heated in a mixed vessel, 5 min. at 90° C., and cooled to 65° C. [0174] 2. Starch phase, water phase, and egg phase are mixed using a colloid mill, and oil phase is added while recirculating.

[0175] The Stevens values (for consistency of the emulsions) at 20° C. and the syneresis values (for stability of the emulsions) at 5° C. and 20° C. were measured up to a storage time of 12 weeks (for syneresis) and 16 weeks (for Stevens). The results are given in the following Table 3:

TABLE-US-00003 TABLE 3 Stevens value and syneresis value for emulsions from Table 1 as function of time (in weeks). 0 wk 1 wk 2 wk 4 wk 6 wk 8 wk 10 wk 12 wk 16 wk Emulsion 314 (comparative) Stevens 20° C. [g] 65 68 70 71 80 Syneresis 5° C. [g] 0 0.9 2.2 5.5 6.4 7.8 8 8.1 Syneresis 20° C. [g] 0 1.5 3 5.5 6.8 7.5 8.5 8.5 Emulsion 315 (comparative) Stevens 20° C. [g] 75 75 72 70 80 Syneresis 5° C. [g] 0 0 0.3 1 1.8 2.2 2.7 3 Syneresis 20° C. [g] 0 0 0.5 1.2 1.5 2 2.3 3 Emulsion 316 Stevens 20° C. [g] 95 100 97 109 126 Syneresis 5° C. [g] 0 0 0 0.2 0.2 0.5 0.5 0.5 Syneresis 20° C. [g] 0 0 0 0 0 0.2 0.3 0.3 Emulsion 317 (comparative) Stevens 20° C. [g] 56 75 63 61 63 Syneresis 5° C. [g] 0 0 0 0.5 0.8 1.1 1.5 1.8 Syneresis 20° C. [g] 0 0 0.3 1.1 0.9 1.5 2 2.5 Emulsion 318 Stevens 20° C. [g] 70 75 75 79 90 Syneresis 5° C. [g] 0 0 0.4 1.3 2.0 2.7 3.2 3.8 Syneresis 20° C. [g] 0 0.2 0.8 1.8 2.5 3.5 4 5

[0176] This example shows that the emulsions prepared according to the methods of the invention (316 and 318) show good Stevens value, while that of the comparative compositions is lower. Emulsion 316 also has favourably low syneresis values. The syneresis of emulsion 318 is relatively high. Nevertheless we will see in example 2 that emulsion prepared according to the same process as this emulsion 318 have very low and thus favourable syneresis values.

[0177] The comparative examples are not stable upon storage during 12 weeks, as their syneresis values are relatively high. Moreover, their Stevens values are relatively low, meaning that their firmness is not high. Using the processes of the invention yields better structuring than the comparative examples.

Example 2—Emulsions Containing Various Concentrations of Wheat Flour and Physically Modified Starch

[0178] Oil-in-water emulsions were prepared having compositions as in the following table.

TABLE-US-00004 TABLE 4 Compositions of prepared oil-in-water emulsions. 1 2 3 4 5 6 7 8 9 10 11 12 Conc. Conc. Conc. Conc. Conc. Conc. Conc. Conc. Conc. Conc. Conc. Conc. [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] Vinegar 1.28 1.28 1.28 1.28 1.28 1.28 1.28 1.28 1.28 1.28 1.28 1.28 Lactic acid 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 Egg yolk 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 HM pectin 0.00 0.00 0.00 0.00 0.00 0.15 0.00 0.15 0.30 0.00 0.15 0.30 Sunflower oil 37.70 37.70 37.70 37.70 37.70 37.70 37.70 37.70 37.70 37.70 37.70 37.70 Flavour 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Wheat flour 0.00 1.30 2.60 3.25 3.90 3.90 5.20 5.20 5.20 6.50 6.50 6.50 Salt 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 Sucrose 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 EDTA 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 Physically 4.00 3.20 2.40 2.00 1.60 1.60 0.80 0.80 0.80 0.00 0.00 0.00 modified starch Demineralised 49.86 49.36 48.86 48.61 48.36 48.21 47.86 47.71 47.56 47.36 47.21 47.06 water

[0179] Each emulsion was prepared using the following process: [0180] A mixture was made of water, wheat flour, salt, sucrose, EDTA and physically modified starch in a mixed vessel at room temperature, and subsequently heated 5 min. at 90° C., and cooled to 65° C. [0181] This aqueous phase, acids, and egg yolk were mixed using a colloid mill, and oil phase (which includes flavour and optionally HM-pectin) was added while recirculating to prepare the oil-in-water emulsions.

[0182] This process is similar to the combined heating of the wheat flour and physically modified starch in emulsion 318 in example 1.

[0183] The Stevens values (for consistency of the emulsions) at 20° C. and the syneresis values (for stability of the emulsions) at 5° C. and 20° C. were measured. The results are given in the following tables. Also the oil droplet diameter and rheological properties were determined. Samples containing only wheat flour (no physically modified starch) were not smooth, were regarded to be floury. The other emulsions had a good structure and stability.

TABLE-US-00005 TABLE 5 Stevens value for emulsions from Table 4 as function of time. Stevens 15 min Stevens 7 days Stevens 30 days Emulsion [g] [g] [g] 1 74  98 101 2 69 110 114 3 65 107 120 4 68 109 121 5 66 112 117 6 65 109 113 7 65 110 112 8 69 112 124 9 78 113 116 10  55  91  96 11  68 103 107 12  69 107 110

TABLE-US-00006 TABLE 6 Syneresis value for emulsions from Table 4 as function of time at 20° C. Emul- 1 wk 2 wks 4 wks 6 wks 8 wks 10 wks 12 wks sion (20° C.) (20° C.) (20° C.) (20° C.) (20° C.) (20° C.) (20° C.) 1 0 0 0 0.0 0.1 0.1 0.13 2 0 0 0 0.1 0.1 0.2 0.25 3 0 0 0 0.1 0.2 0.3 0.32 4 0 0 0 0.1 0.2 0.2 0.32 5 0 0 0 0.1 0.1 0.3 0.35 6 0 0 0 0.0 0.1 0.1 0.09 7 0 0 0 0.1 0.2 0.3 0.45 8 0 0 0 0.0 0.0 0.1 0.05 9 0 0 0 0.0 0.0 0.0 0.00 10 0 0 0 0.0 0.1 0.1 0.16 11 0 0 0 0.0 0.0 0.0 0.03 12 0 0 0 0.0 0.0 0.0 0.00

TABLE-US-00007 TABLE 7 Syneresis value for emulsions from Table 4 as function of time at 5° C. Emul- 1 wk 2 wks 4 wks 6 wks 8 wks 10 wks 12 wks sion (5° C.) (5° C.) (5° C.) (5° C.) (5° C.) (5° C.) (5° C.) 1 0 0 0 0.0 0.1 0.1 0.20 2 0 0 0 0.0 0.1 0.2 0.29 3 0 0 0 0.0 0.1 0.2 0.32 4 0 0 0 0.0 0.1 0.2 0.23 5 0 0 0 0.0 0.1 0.1 0.20 6 0 0 0 0.0 0.0 0.0 0.06 7 0 0 0 0.0 0.1 0.2 0.35 8 0 0 0 0.0 0.0 0.0 0.02 9 0 0 0 0.0 0.0 0.0 0.00 10 0 0 0 0.0 0.0 0.1 0.14 11 0 0 0 0.0 0.0 0.0 0.00 12 0 0 0 0.0 0.0 0.0 0.00

TABLE-US-00008 TABLE 8 Mean oil droplet value D3,2, dynamic viscosity, and G′ values for emulsions from Table 4. Droplet size D3,2 Viscosity at 50 s.sup.−1 G′ at 1% strain Emulsion [μm] [Pa .Math. s] [Pa] 1 4.26 2.62 451 2 4.49 2.43 472 3 4.38 2.55 558 4 4.21 2.52 547 5 4.21 2.47 495 6 4.27 2.79 519 7 4.44 2.63 574 8 4.33 3.08 566 9 5.52 3.83 563 10  6.11 2.82 411 11  4.66 3.36 465 12  4.66 3.32 503

[0184] The samples containing physically modified starch and wheat flour had a good stability with regard to syneresis. This was even further improved when high methoxyl pectin was present in these compositions (emulsions 6, 8, 9, 10, and 11).