Use of sulfhydryl oxidase to increase the viscosity and / or gel strength of egg-containing foods

Abstract

Use of sulfhydryl oxidase to increase the viscosity and / or gel strength of an egg-containing, egg yolk-containing or egg protein-containing preparation.

Description

[0001] The present invention describes the use of a sulfhydryl oxidase to increase the viscosity and / or gel strength of compositions made with egg, egg yolk, and / or egg proteins, e.g., foodstuffs. This allows, for example, if desired, to reduce the proportion of egg, egg yolk, or egg proteins and thus, among other things, cholesterol. State of the art

[0002] Mayonnaise is a thick, cold-processed sauce, an emulsion of oil in water based on egg yolk and oil, or water, lecithin, and fat. The lecithin from the egg yolk serves as an emulsifier.

[0003] To make it, egg yolk is usually mixed with salt, pepper, and a little liquid (water, lemon juice, vinegar). Adding mustard facilitates emulsification. While stirring vigorously, oil is gradually added. At the beginning of the emulsification process, it is usually important to add the oil gradually to prevent the emulsion from breaking (leading to a water-in-oil emulsion). The goal is to achieve certain rheological properties of the finished preparation, such as a certain thickness, texture, and viscosity.

[0004] Mayonnaise can also be made with pasteurized or hard-boiled egg yolk or egg powder, as this does not reduce the emulsifying properties of the lecithin.

[0005] It's also possible to replace the egg yolk with milk. The milk proteins act as an emulsifier and, given the high shear forces, can be sufficient to create an emulsion.

[0006] To thicken mayonnaise, it can be vigorously whipped. This further breaks down the oil droplets in the emulsion, making them smaller and smaller. US Pat. No. 6,793,958 describes suitable processes for this and discusses other ways to achieve the desired rheological properties. The viscosity of liquid compositions or the gel strength of solid compositions can also be increased by adding gelatin, pectin, or starch (e.g., US Pat. No. 7,052,729 B2).

[0007] The use of phospholipase in egg processing (e.g. EP 0 426 211 B1) to increase viscosity or gel strength is also known in the prior art.

[0008] DE 602 19 600 T2 describes the use of a sulfhydryl oxidase to improve the emulsifying properties of eggs, soy or milk.

[0009] The publication by Gerrard J., “Protein-protein crosslinking in food: methods, consequences, applications”, Trends in Food Science & Technology, Vol. 13, 2002, Issue 12, pages 391-399 discusses the various methods for the formation of protein-protein bonds that can potentially be used in food. Description

[0010] In the prior art, the problem of adjusting the viscosity or gel strength of preparations to the desired value is solved using a variety of methods. The present invention, as described in the claims, relates to an advantageous use of the enzyme sulfhydryl oxidase. It has surprisingly been found that sulfhydryl oxidase increases the stability of the products (viscosity and / or gel strength) in products containing egg, egg yolk, or egg protein.

[0011] The invention therefore relates to the use of sulfhydryl oxidase for increasing the viscosity and / or gel strength of an egg-containing, egg yolk-containing or egg protein-containing preparation.

[0012] Sulfhydryl oxidase belongs to the class of oxidoreductases (EC 1.8.3.2). It catalyzes the oxidation of two sulfhydryl groups to a disulfide bridge with the loss of hydrogen peroxide according to the scheme RSH + O2 = RSSR + H2O2.

[0013] Previous patents describe the use of sulfhydryl oxidase in combination with other enzymes such as glucose oxidase (US Pat. No. 5,547,690 A), cellulases, or hemicellulases (US Pat. No. 4,990,343 A) to improve the baking properties of flours. In these applications, the effect of sulfhydryl oxidase is attributable to the glutenin fraction of the gluten.

[0014] EP 0 947 142 B1 states that sulfhydryl oxidase is used to cross-link proteins and can be used in the food processing of meat, yogurt, jelly, and cheese. This does not provide any indication of a potential for increasing the viscosity and / or gel strength of egg- or egg yolk-containing products and egg protein solutions.

[0015] The use of sulfhydryl oxidase on an industrial scale has recently been simplified by the availability of a sulfhydryl oxidase with greater stability, namely sulfhydryl oxidase from brewer's yeast, Saccharomyces cerevisiae, and the replacement of the cysteine ​​groups with serine by means of protein engineering (DE 10309169 A1). Within the scope of the invention, sulfhydryl oxidase from Saccharomyces cerevisiae is preferably used, in particular, for example, the sulfhydryl oxidase disclosed in DE 10309169 A1, which has increased stability compared to the wild type.

[0016] Within the scope of the invention, it has now been found that sulfhydryl oxidase can be advantageously used to increase the viscosity and / or gel strength of egg-containing, egg yolk-containing or egg protein-containing preparations.

[0017] The preparation is, in particular, a food or an ingredient for the manufacture of a food. It can be, for example, mayonnaise, mayonnaise-like or mayonnaise-containing preparations, dressings (e.g., salad dressings), puddings, flans, ice cream, creams, milkshakes, or other egg-containing preparations such as hollandaise sauce and its modifications, cake mixtures, or even alcohol-containing egg preparations.

[0018] In one embodiment, the preparations may contain flour or glutenin from gluten and / or other proteins from sources other than egg, in another embodiment they do not contain these components.

[0019] If desired, the viscosity increase by sulfhydryl oxidase can be used to reduce the proportion of egg, egg yolk, and / or egg protein without reducing the viscosity of the preparation. The egg content is typically considered a limiting factor for viscosity, which is also reflected in the results described below.

[0020] The resulting food may therefore contain a lower proportion of egg, egg yolk, egg protein (egg component), and / or cholesterol than a product of the same viscosity without sulfhydryl oxidase. This is helpful, for example, in certain dietary requirements or medical conditions that require a reduction in cholesterol intake.

[0021] Furthermore, this leads to significant cost savings, as the egg component typically contributes significantly to the cost of the product.

[0022] Alternatively, the proportion of egg component can be kept the same, whereby the viscosity increases compared to a product in which no sulfhydryl oxidase was used.

[0023] The preparation or food can be a solid preparation, a solution, or an emulsion, e.g., an oil-in-water emulsion or a water-in-oil emulsion. Within the scope of the invention, it was surprisingly discovered that the use of sulfhydryl oxidase promotes the formation of emulsions with higher viscosity.

[0024] The viscosity of the sulfhydryl oxidase-containing preparation is, for example, between 100 and 20,000 mPa s (at 20°C). In particular, a viscosity of over 2,000 mPa s, over 3,000 mPa s, over 7,000 mPa s, over 8,000 mPa s, over 8,500 mPa s, or over 10,000 mPa s (at 20°C) is achieved. Advantageously, the viscosity is stable in this range for more than one day, two to three days, one week, or several weeks (e.g., more than 2 or 3 weeks).

[0025] In solid preparations, e.g. flan, the firmness is also increased.

[0026] The egg yolk content of the sulfhydryl oxidase-containing preparation is preferably between 0.01% and 100% by weight, in particular between 1% and 99% by weight, between 5% and 95% by weight, between 10% and 90% by weight, between 20% and 80% by weight, or between 30% and 50% by weight. By using a concentrated or dried egg product or egg yolk product, the egg yolk content can also be between 100 and 190% by weight, whereby the content is always stated relative to whole egg.

[0027] Within the scope of the invention, 0.005% to 0.1% (wt%) sulfhydryl oxidase, in particular 0.01% to 0.05% or up to 0.025% sulfhydryl oxidase, is used (e.g., 100-250 mg / kg). Advantageously, the activity of the sulfhydryl oxidase is 0.01 U / g to 10 U / g, in particular 0.1 to 1 U / g.

[0028] Also disclosed herein is, for example, a process for producing a food containing an egg component (e.g., an emulsion, in particular a mayonnaise), which comprises steps in which the food preparation is brought into contact with 0.01 wt.% sulfhydryl oxidase with an activity of 0.1 U / g. This increases the viscosity of the food. For example, a viscosity of over approximately 8500 mPa s (at 20°C) is achieved.

[0029] During the preparation of the composition, sulfhydryl oxidase can be added to the egg component, for example, or added after the egg component has been mixed with other ingredients and mixed. To create an emulsion, the mixture is subjected to shear forces.

[0030] To prepare the composition with increased viscosity, incubation preferably takes place at room temperature (approx. 20°C) up to approx. 37°C, in particular approx. 25°C to approx. 30°C.

[0031] Also disclosed herein is an edible emulsion containing a) water, b) oil, c) egg, egg yolk, and / or egg protein, d) one or more spices, flavorings, sugar, and / or table salt, and e) sulfhydryl oxidase. This emulsion may be a water-in-oil or an oil-in-water emulsion, in particular a mayonnaise or a dressing. The preparation may also contain preservatives.

[0032] The present invention also describes a sulfhydryl oxidase-containing whole egg product, egg yolk product, or egg protein product suitable for the production of such products, e.g., a composition containing or consisting of egg yolk powder and sulfhydryl oxidase. This composition is preferably dry and stable for several weeks or several months (e.g., more than 1-2 weeks or more than 1-2 months). This composition can be absorbed, optionally after mixing with other ingredients, e.g., in water and / or oil.

[0033] A composition prepared as described herein (in particular an emulsion) preferably has a viscosity between 100 and 20,000 mPa s (at 20°C), in particular a viscosity of more than 3,000 mPa s, more than 8,000 mPa s, more than 8,500 mPa s, or more than 10,000 mPa s (at 20°C) is achieved. Advantageously, the viscosity is stable in this range for one day or two to three days, one week, or several weeks (e.g., more than 2 or 3 weeks).

[0034] The emulsion contains in particular 0.005 to 0.1 wt.% of a sulfhydryl oxidase, in particular 0.01 wt.% of a sulfhydryl oxidase with an activity of 0.01 U / g to 10 U / g, in particular 0.1 to 1 U / g.

[0035] In one embodiment, the composition prepared as described herein contains no cereal flour and / or flour gluten. The compositions may optionally contain thickeners such as guar gum, starch, pectin, and / or gelatin to achieve the desired texture of the composition.

[0036] In this study, sulfhydryl oxidase from Saccharomyces cerevisiae was added to solutions and suspensions of plant and animal proteins, as well as combinations thereof, in a wide range of concentrations. Surprisingly strong changes in the rheology of egg and egg protein-containing mixtures were observed. In addition to improving quality, this also opens up potential for savings, as the same stabilizing effect can be achieved with less protein. Furthermore, the cholesterol content of egg-containing products is reduced without adversely affecting the structure. legend Fig.1: Viscosity of emulsions with different egg yolk and enzyme concentrations Fig. 2: Influence of sulfhydryl oxidase on the viscosity of a model food system (10% egg yolk solution) (wt%) Fig. 3: Stability of a protein solution with 0.7 wt% egg yolk Fig. Figure 4A: Influence of sulfhydryl oxidase on the shape stability of flan caramel. From left to right: 0, 1, 2.5, and 10 mU sulfhydryl oxidase per 100 g flan mass. Fig. Figure 4B: Influence of sulfhydryl oxidase on the homogeneity of flan caramel. From left to right: 0, 1, 2.5, and 10 mU sulfhydryl oxidase per 100 g flan mass. Fig. 4C: Influence of sulfhydryl oxidase on the stability of flan caramelo (expressed as resistance to uniaxial compression with a spherical probe). ExamplesDefinition of sulfhydryl oxidase activity

[0037] 1 unit (U) of sulfhydryl oxidase is defined, as is customary in the art, as the amount of enzyme that produces 1 nmol of oxidized thiol groups in 1 min at pH 7.4 and 30 °C. Reduced DTT [dithiothreitol] serves as the substrate. Detection is performed with DTNB [5,5'-dithiobis-(2-nitrobenzoic acid)], which reacts with free thiol groups to form the colored p-nitrophenol anion (Ellman's reagent). The decrease in OD is measured. 412 over a period of 25 min compared to a sample without enzyme (reference), zero adjustment is carried out with PBS (phosphate buffered saline) + 100 µl DTNB. Example 1

[0038] Emulsions with varying egg yolk contents were treated with sulfhydryl oxidase. The emulsions consisted of 67 wt% sunflower oil, 22.6 wt% to 22.8 wt% tap water (1.78 mmol / l CaCO3, 10 °dH), 4 wt% acetic acid, 4 wt% sugar, 1.5 wt% salt, and 0.7 to 0.9 wt% egg yolk powder (Hamegg Nootbar GmbH). For preparation, salt and sugar were first dispersed into the water in a 600 ml beaker within 20 seconds using a Krups electric hand mixer (model 3 Mix 8000). Except for the control, 0.01 wt% sulfhydryl oxidase was added to the egg yolk powder. It was then suspended in a small amount of sunflower oil and dispersed into the water. After a 2-minute swelling time, the remaining sunflower oil was slowly added under high shear forces. Finally, the 10% acetic acid was added. The emulsion was homogenized for 90 seconds using a Braun hand blender (model MR400).The assessment was made after 24 hours.

[0039] Viscosities were measured using Brookfield rotational viscometers. Depending on the viscosity, the RVDV-II+ model was used for higher-viscosity samples (over 3000 mPa s) or the LVDV-II+ model for lower-viscosity samples. The RV4 and RV5 disk spindles were used for the RVDV-II+ model, and the LV1 cylindrical spindle was used for the LVDV-II+ model. The diameter and height of the spindles are listed in Table 1. Table 1: Diameter and height of the spindles used for viscosity measurement spindle name Diameter (mm) Height (mm) RV4 27,3 1,65 RV5 21,14 1,65 Level 1 18,84 53,95

[0040] It was found that with the help of sulfhydryl oxidase, the amount of egg yolk required to achieve the standard viscosity of approximately 8500 mPa s (at 20°C) could be reduced from 0.9 wt% to 0.8 wt%, a saving of over 10% (see Fig. 1). Example 2

[0041] To prepare a protein-containing solution, 10 wt.% of egg yolk powder (Hamegg Nootbar GmbH), 1 wt.% guar gum, and 0.01 wt.% propyl 4-hydroxybenzoate (trade name: Nipasol®; Clariant) were mixed together and dispersed in cold tap water (1.78 mmol / l CaCO3, 10 °dH) within 30 seconds using a Krups electric hand mixer (model 3 Mix 8000). After a soaking time of 30 minutes, the solution was heated to 85 °C over 45 minutes in a 90 °C water bath, stirring with the hand mixer every 5 minutes for 10 seconds at the lowest setting, and kept hot for 5 minutes. The samples were then cooled to 37 °C in a cold water bath over 20 minutes. Except for the control, 0.01 wt% sulfhydryl oxidase was then added.The mixtures were covered with aluminum foil, incubated for 18 hours at 37 °C, and then cooled to 20 °C within 4 hours and assessed. Using 0.01 wt% sulfhydryl oxidase in 10% egg yolk solution (corresponding to 1 U / kg sulfhydryl oxidase), a viscosity increase of almost 50% was achieved (see ). Fig. 2). Example 3

[0042] Example 3 concerns the application of sulfhydryl oxidase in 0.7% egg yolk solutions. To prepare a protein solution, 0.7 wt.% of egg yolk powder (Hamegg Nootbar GmbH), 1 wt.% guar gum, and 0.01 wt.% propyl 4-hydroxybenzoate (trade name: Nipasol®; Clariant) as a preservative were mixed together and dispersed in cold tap water (1.78 mmol / l CaCO3, 10 °dH) within 30 seconds using a Krups electric hand mixer (model 3 Mix 8000). After a soaking time of 30 minutes, the solutions were heated to 85 °C within 45 minutes in a 90 °C water bath, stirring with a hand mixer every 5 minutes for 10 seconds at the lowest setting. The mixture was then kept hot for 5 minutes. The samples were then cooled to 37 °C in a cold water bath within 20 minutes. Except for the control, 0.01 wt% sulfhydryl oxidase was then added.The cultures were covered with aluminum foil, incubated for 18 hours at 37 °C, and then cooled to 20 °C within 4 hours and evaluated. Further measurements were taken after 3 and 7 days of storage at 20 °C (see ). Fig. 3).

[0043] It was shown that sulfhydryl oxidase at a dosage of 0.01 wt.% can increase the viscosity of a 0.7% egg yolk solution by almost 1 / 3 and that the stability does not decrease again even over a period of 7 days. Example 4

[0044] Example 4 shows the effect of sulfhydryl oxidase on the firmness of egg custard (flan, e.g. Flan Caramelo).

[0045] The flan was made according to the following recipe: Unit A B C D Milk g 1 1 000 1 000 1 000 Owner (1) g 000 600 600 600 Sugar g 600 150 150 150 150 SOX 100 (2) g 0 0,18 0,44 1,75 sum g 1750 1750 1750 1750 SOX mU / 100g 0 1 2,5 10 SOX 100 mg / kg 0 100 250 1000 (1) Pasteurized whole egg (2) SOX 100 = Sulfhydryloxidase mit 100 mU / g

[0046] Heat half of the milk with all the sugar to 90°C while stirring. Remove from the heat, add the remaining milk, and bring to a temperature of 50°C. Add the eggs and whisk, divide the mixture into 4 portions, add sulfhydryl oxidase (SOX 100), and whisk. Pour the mixture into containers (filling height > 2 cm), cover, and let stand at room temperature for 90 minutes. Then, heat the mixture in a water bath until the mixture solidifies (approx. 45 minutes). Remove the containers from the water and allow to cool in a cold room (48 hours at 10°C).

[0047] For assessment, the flan is removed from the vessel and its shape and firmness are assessed: A. Form assessment

[0048] By adding sulfhydryl oxidase, the shape stability of the flan was improved ( Fig. 4A). A further effect was a reduction in the size of trapped gas bubbles (improved homogeneity; Fig., which showed a clear dependence on the dosage of sulfhydryl oxidase. It can be assumed that stabilizing the still-liquid mass prevented the gas bubbles from coalescing and thus from growing. B. Determination of strength

[0049] The strength of the flanges was determined using a texture measuring device (Texture Analyzer TAXT2 from Newport Scientific / Perten Instruments). For this purpose, the flanges taken from the vessels were compressed to 50% of their height in the Texture Analyzer using a spherical probe. The resulting resistance force was measured in Fig. plotted against enzyme activity. At 2.5 milliunits (mU) of sulfhydryl oxidase per 100 g of flan mass, a significant increase in solidification occurred, which improved slightly at 10 mU.

[0050] The results show that the use of sulfhydryl oxidase improves viscosity and thus dimensional stability, texture and strength even in solid compositions.

Claims

[1] Use of sulfhydryl oxidase to increase the viscosity and / or gel strength of an egg-containing, egg yolk-containing or egg protein-containing preparation. [2] Use according to claim 1, characterized by that the preparation is a food or an ingredient for the manufacture of a food. [3] Use according to claim 2, characterized by that the preparation contains a lower proportion of egg, egg yolk, egg protein and / or cholesterol than a product of the same viscosity without sulfhydryl oxidase. [4] Use according to one of the preceding claims, characterized by that the preparation is a solid preparation, a solution, an oil-in-water emulsion or a water-in-oil emulsion. [5] Use according to one of the preceding claims, characterized by that the preparation is a mayonnaise. [6] Use according to one of the preceding claims, characterized bythat the egg yolk content of the preparation containing sulfhydryl oxidase is between 0.01 and 190% by weight, whereby by using a concentrated or dried egg product or egg yolk product the egg yolk content can also be between 100 and 190% by weight, whereby the proportion is always given in relation to whole egg. [7] Use according to one of the preceding claims, characterized by that the viscosity of the preparation containing sulfhydryl oxidase is between 100 and 20000 mPa·s at 20°C. [8] Use according to one of the preceding claims, characterized by that 0.005 to 0.1% by weight of sulfhydryl oxidase, in particular 0.01% by weight of sulfhydryl oxidase, is used, the activity of the sulfhydryl oxidase being 0.01 U / g to 10 U / g. [9] Use according to claim 8, characterized by that the activity of sulfhydryl oxidase is 0.1 to 1 U / g.

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