Method of manufacturing vegetable egg white substitute including albumin derived from vegetable, vegetable egg white substitute manufactured by the same and maringue cookie manufactured by the same

Abstract

The present invention relates to a method for manufacturing a plant-derived egg white substitute comprising a raw material manufacturing step of extracting albumin from soybeans to produce an albumin solution, wherein the raw material manufacturing step may include: a soy milk manufacturing step of preparing soy milk by crushing peeled soybeans and mixing them with water; a first pH adjustment step of adding a base to the soy milk and stirring; a first separation step of separating the supernatant by centrifuging the pH-adjusted soy milk; a second pH adjustment step of adding an acid to the separated protein mixture and stirring; and a second separation step of collecting the albumin solution by centrifuging the pH-adjusted protein mixture.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a plant-based egg white substitute comprising plant-derived albumin, a plant-based egg white substitute manufactured according to the method, and a meringue cookie manufactured therefrom. More specifically, the invention relates to a method for manufacturing a plant-based egg white substitute that improves the foam-forming ability, retention ability, and thermal stability of the plant-based egg white substitute, thereby enabling the realization of the shape, texture, and mouthfeel of a conventional meringue cookie when using the substitute to manufacture a plant-based meringue cookie, a plant-based egg white substitute manufactured according to the method, and a meringue cookie manufactured with the plant-based egg white substitute. Background Technology

[0003] Recently, the demand for plant-based foods has been steadily increasing due to various environmental issues, such as reducing carbon emissions, mitigating climate change, and addressing animal welfare. As a result of this trend, the vegetarian market is growing, and consumer preference for healthier and more eco-friendly foods is also rising. However, since the physical and chemical properties—such as texture, microstructure, and mouthfeel—of currently commercialized plant-based products differ significantly from those of animal-based products, multifaceted research is required to identify plant-based products that possess similar physical and chemical characteristics and can completely replace animal-based products.

[0004] Meanwhile, meringue is a confection made by mixing egg whites and sugar. Depending on the whipping process and the balance of ingredients, a fine structure is formed, resulting in a unique structure with an air content exceeding 80%. Consequently, it creates a distinctive texture and mouthfeel that is different from ordinary cookies, bread, or pastries. This meringue can be applied to confectionery products such as meringue cookies made entirely of meringue or macarons filled with cream-like fillings between meringue layers, as well as baking products such as soufflés and omelets. Due to its unique texture, it is widely loved around the world.

[0005] The fine structure of such meringue is formed when air is trapped between the egg whites during vigorous whipping; however, this characteristic is not realized when using vegetable egg whites. In particular, animal egg whites exhibit a unique structure, texture, and mouthfeel because they maintain their foam structure during heating, in addition to these distinctive foaming properties. In contrast, with vegetable egg whites, not only is it difficult to trap air, but even if some air is trapped, the fine foam structure breaks down during cooking due to low thermal stability. Consequently, there has been a problem in manufacturing meringues, macarons, and other products using vegetable egg whites.

[0006] As such, egg white meringue plays a pivotal role in confectionery; however, products currently utilizing it as a plant-based substitute often suffer from somewhat weak shape stability during the dough-making and shaping processes. Furthermore, problems persist where it is shunned by consumers, as it offers no nutritional advantages relative to its proportion in the product and struggles to maintain its structure due to its vulnerability to heat during baking. Prior art literature

[0008] Registered Patent No. 10-2543868 (Registered June 12, 2023) The problem to be solved

[0009] The present invention aims to provide a method for manufacturing a plant-based egg white substitute that improves foam-forming ability, retention ability, and thermal stability, thereby enabling the realization of the shape, texture, and mouthfeel of conventional meringue cookies when using the substitute, a plant-based egg white substitute manufactured according to this method, and meringue cookies made with such a plant-based egg white substitute. means of solving the problem

[0011] One embodiment of the present invention for achieving the above-described purpose relates to a method for manufacturing a plant-derived egg white substitute comprising a raw material preparation step of extracting albumin from soybeans to prepare an albumin solution.

[0012] The above raw material manufacturing step may include: a soy milk manufacturing step in which hulled soybeans are minced and then mixed with water to produce soy milk; a first pH adjustment step in which a base is added to the soy milk and stirred; a first separation step in which the pH-adjusted soy milk is centrifuged to separate the supernatant; a second pH adjustment step in which an acid is added to the separated supernatant and stirred; and a second separation step in which the pH-adjusted protein mixture is centrifuged to collect the albumin solution, which is the supernatant.

[0013] The above second pH adjustment step may be a step of adjusting the pH by adding acid so that the pH of the protein mixture becomes 5 to 8.

[0014] Another embodiment of the present invention relates to a method for producing a plant-derived egg white substitute comprising a drying step of drying an albumin solution.

[0015] The above albumin solution can be prepared through a raw material preparation step of extracting albumin from soybeans to prepare an albumin solution.

[0016] The above raw material manufacturing step may include: a soy milk manufacturing step in which hulled soybeans are minced and then mixed with water to produce soy milk; a first pH adjustment step in which a base is added to the soy milk and stirred; a first separation step in which the pH-adjusted soy milk is centrifuged to separate the supernatant; a second pH adjustment step in which an acid is added to the separated supernatant and stirred; and a second separation step in which the pH-adjusted protein mixture is centrifuged to collect the albumin solution, which is the supernatant.

[0017] The above drying step can be performed by at least one of spray drying, freeze drying, and vacuum drying.

[0018] The above drying step may be a freeze-drying step.

[0019] Another embodiment of the present invention relates to a method for producing meringue cookies using a plant-derived egg white substitute comprising plant-derived albumin, comprising the steps of: mixing and stirring the plant-derived egg white substitute with water and sugar to produce a meringue; panning the meringue onto a tray; and placing the tray containing the meringue batter into an oven and baking it to produce meringue cookies. Effects of the invention

[0021] The plant-based egg white substitute of the present invention is a plant-based raw material and can be used as an egg white substitute for confectionery such as plant-based meringue cookies or macarons.

[0022] In addition, the shape, texture, and mouthfeel of existing meringue cookies can be effectively reproduced. Brief explanation of the drawing

[0024] Figure 1 shows the results of protein electrophoresis analysis of albumin powder. Figure 2 shows the results of measuring the foam-forming ability and foam stability of albumin powder. Figure 3 shows the results of measuring the secretion of the meringue batter. Figure 4 shows the results of measuring the apparent viscosity of the meringue batter. Figures 5 and 6 show the storage factor and loss factor of the meringue batter, respectively. Figure 7 shows the appearance of the meringue batter, the appearance of the meringue dough, and a cross-sectional view of the meringue dough. Figure 8 shows the result of observing a cross-section of a meringue cookie under a microscope. Figure 9 shows the zeta potential measurement results of the albumin solution. Figure 10 shows the results of the electrophoretic analysis of the albumin solution. Figure 11 shows the results of measuring the foam-forming ability and foam stability of the albumin solution. Figure 12 shows the results of measuring the secretion of the meringue batter. Figure 13 shows the results of measuring the apparent viscosity of the meringue batter. Figures 14 and 15 show the storage factor and loss factor of the meringue batter, respectively. Figure 16 shows the appearance of the meringue batter, the appearance of the meringue dough, and a cross-sectional view of the meringue dough. Figure 17 is the result of observing a cross-section of a meringue cookie under a microscope. Specific details for implementing the invention

[0025] Before describing the preferred embodiments of the present invention in detail below, it should be noted that the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0026] Throughout this specification, when a part is described as “comprising” a certain component, it means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0027] Throughout this specification, “%” used to indicate the concentration of a specific substance means (weight / weight)% for solid / solid, (weight / volume)% for solid / liquid, and (volume / volume)% for liquid / liquid, unless otherwise noted.

[0028] Hereinafter, embodiments of the present invention are examined. However, the scope of the present invention is not limited to the following preferred embodiments, and those skilled in the art may implement various modified forms of the contents described herein within the scope of the present invention.

[0029] The present invention relates to a method for manufacturing a plant-based egg white substitute comprising plant-derived albumin, wherein the foam-forming ability, retention ability, and thermal stability of the plant-based egg white substitute are improved so that the shape, texture, and mouthfeel of conventional meringue cookies can be realized when using the plant-based egg white substitute; and to a plant-based egg white substitute manufactured according to the same, a meringue cookie manufactured using said plant-based egg white substitute, and a method for manufacturing the same.

[0030] One embodiment of the present invention relates to a method for manufacturing a plant-derived egg white substitute comprising plant-derived albumin, comprising a raw material preparation step of extracting albumin from soybeans to prepare an albumin solution.

[0031] The above raw material manufacturing step comprises a step of extracting albumin from soybeans to prepare an albumin solution, specifically, a soy milk manufacturing step of mincing peeled soybeans and mixing them with water to prepare soy milk; a first pH adjustment step of adding a base to the soy milk and stirring; a first separation step of centrifuging the pH-adjusted soy milk to separate the supernatant; a second pH adjustment step of adding an acid to the separated supernatant and stirring; and a second separation step of centrifuging the pH-adjusted protein mixture to collect the albumin solution, which is the supernatant.

[0032] Albumin is one of the proteins that constitute the basic material of cells and is abundantly found in egg whites; it is a substance that enables the formation or maintenance of bubbles when producing foamed foods, such as meringue, using egg whites. In this invention, albumin derived from plant-based raw materials, rather than animal-based raw materials such as eggs, can be provided.

[0033] To prepare the albumin solution, a soy milk preparation step is first performed, in which hulled beans are minced and then mixed with water to produce soy milk. In this step, the soybeans used as raw materials are not particularly limited and can be used as soybeans, cowpeas, peas, kidney beans, chickpeas, broad beans, etc., but it is preferable to use cowpeas.

[0034] Since the hulls of the soybeans are a factor that interferes with albumin extraction in subsequent steps, it is desirable to remove them at this stage, and soy milk can be prepared by mincing the hulled soybeans and mixing them with water. When preparing soy milk, the ratio of the weight of the soybeans to the volume of water (w / v) can be mixed in a ratio of 1:3 to 10.

[0035] Next, a first pH adjustment step is performed by adding a base to the soybean milk and stirring. Through this step, albumin contained in the soybeans can be eluted into the solvent. The pH can be adjusted to 7.5 to 9.5, and for pH adjustment, for example, NaOH can be used as the base, but any base suitable for food pH adjustment can be used without limitation.

[0036] Next, a primary separation step is performed in which the pH-adjusted soybean milk is centrifuged to separate the supernatant. The centrifugation conditions are not specifically limited, but, for example, can be performed at a speed of 1,000 to 20,000 rpm for 10 to 40 minutes. After centrifugation, the supernatant is obtained to separate proteins from the soybean milk.

[0037] Next, a second pH adjustment step is performed in which an acid is added to the separated protein mixture and stirred. Through this step, the pH can be adjusted to 5 to 8, preferably 6 to 8, and more preferably 6 to 7. Since the foam-forming and foam-retaining abilities of the finally obtained vegetable egg white substitute containing albumin are excellent when adjusted to this pH range, it is desirable to adjust the pH to the aforementioned range. For example, HCl may be used as the acid added to adjust the pH in this step, but is not limited thereto, and any food additive may be used.

[0038] Next, a secondary separation step is performed to collect the albumin solution by centrifuging the pH-adjusted protein mixture. In this step, centrifugation may be performed, for example, at a speed of 1,000 to 20,000 rpm for 5 to 30 minutes, but this is an exemplary condition and the centrifugation conditions are not limited thereto.

[0039] Through this centrifugation process, the albumin solution, which is the supernatant, can be obtained.

[0040] Another embodiment of the present invention relates to a method for producing a plant-derived egg white substitute comprising a drying step of drying an albumin solution.

[0041] The above albumin solution may be prepared through a raw material preparation step of extracting albumin from soybeans to prepare an albumin solution. Such an albumin solution may be prepared according to one embodiment of the present invention, and accordingly, some redundant descriptions are omitted.

[0042] The above raw material manufacturing step may include: a soy milk manufacturing step in which hulled soybeans are minced and then mixed with water to produce soy milk; a first pH adjustment step in which a base is added to the soy milk and stirred; a first separation step in which the pH-adjusted soy milk is centrifuged to separate the supernatant; a second pH adjustment step in which an acid is added to the separated supernatant and stirred; and a second separation step in which the pH-adjusted protein mixture is centrifuged to collect the albumin solution, which is the supernatant.

[0043] The drying step described above is a step of drying the albumin solution prepared by the above method. This step involves drying the albumin solution to powder it. Since using the albumin solution in a liquid state makes weighing difficult and dough formation is difficult due to its high moisture content when applied to confectionery or baking, it is preferable to prepare it as powdered albumin.

[0044] As a drying method for powdering albumin, at least one of spray drying, freeze drying, and vacuum drying may be applied.

[0045] Preferably, a freeze-drying method may be applied. In this case, unlike other drying methods, the material is not exposed to heat, so protein aggregation caused by heat and subsequent structural deformation do not occur. Therefore, when manufacturing foods such as confectionery and bread using albumin, there is an advantage in that functions such as foam generation and foam retention capabilities of albumin can be effectively realized.

[0046] After drying, a grinding process for pulverization may be performed, and if necessary, sieving may be additionally performed to ensure uniform particle size.

[0048] Another embodiment of the present invention relates to a method for producing meringue cookies using a plant-based egg white substitute comprising plant-derived albumin according to one embodiment of the present invention or another embodiment of the present invention.

[0049] The method for manufacturing a meringue cookie according to the present embodiment comprises the steps of: mixing and stirring a vegetable egg white substitute, water, and sugar to produce a meringue; panning the meringue onto a tray; and placing the tray containing the meringue batter into an oven and baking it to produce a meringue cookie. The vegetable egg white substitute mentioned in the present embodiment is a vegetable protein substitute prepared according to one embodiment of the present invention, and redundant descriptions are omitted.

[0050] First, a step of preparing a meringue is performed by mixing and stirring a plant-derived egg white substitute containing plant-derived albumin with water and sugar. At this time, 500 to 1,500 parts by weight of water and 100 to 600 parts by weight of sugar may be mixed with 100 parts by weight of the egg white substitute.

[0051] At this stage, when making meringue by mixing vegetable egg white substitute, water, and sugar, the entire measured amount of sugar may be mixed in at once. Alternatively, it is possible to make meringue by adding the sugar in portions and stirring; for example, it is possible to make meringue by first mixing and stirring the entire measured amount of vegetable egg white substitute and water with half of the measured sugar, and then adding the remaining sugar and stirring. Stirring can be performed using a mechanical mixer such as a hand mixer or a whisk.

[0052] Next, the step of panning the meringue onto a tray is performed. The size or shape of the meringue panned onto the tray is not particularly limited.

[0053] Finally, a step of making meringue cookies is performed by placing the tray containing the meringue batter into an oven and baking it. At this time, the heat treatment in the oven can be performed at 80 to 120°C for 70 to 120 minutes.

[0054] Plant-based meringue cookies can be manufactured through these steps, and since the meringue cookies are manufactured using a plant-based egg white substitute containing plant-derived albumin according to one embodiment of the present invention, dense air bubbles are formed during meringue production to achieve a firm texture, and the stability of these air bubbles is excellent so that the air bubble structure is stably maintained even during heat treatment, thereby providing plant-based meringue cookies that are similar in shape and texture to meringue cookies made using animal-based ingredients.

[0055] The present invention comprises a meringue cookie prepared according to the above-described embodiment, and the specific operation and effects of the present invention are to be explained below through an embodiment of the present invention. However, this is presented as a preferred example of the present invention, and the scope of the rights of the present invention is not limited according to the embodiment.

[0057] [Preparation Example 1]

[0058] Albumin powder manufacturing

[0059] First, the hulls of cowpeas were removed and minced to prepare a cowpea dough. The cowpea dough was mixed with water in a ratio of 1:5 (w / v) to prepare soy milk. A 1N NaOH aqueous solution was added to the soy milk to adjust its pH to 8.5, and the mixture was stirred at 900 rpm for 1 hour to primarily adjust the pH. The pH-adjusted soy milk was centrifuged at 9,000 rpm for 25 minutes to obtain the supernatant. The pH was further adjusted by adding 1N HCl until the pH of the supernatant reached 7, and the supernatant was obtained through centrifugation again (9,000 rpm, 15 minutes) to prepare an albumin solution. Subsequently, the albumin solution was dried in various ways, ground, and sieved through a 40-mesh sieve to produce albumin powder.

[0060] Depending on the drying method, it was named Comparative Example 1 when spray drying was performed, Example 1 when freeze drying was performed, and Comparative Example 2 when vacuum drying was performed.

[0061] Spray drying was performed using a spray dryer (SD-1010, EYELA) with an inlet temperature of 170℃, an outlet temperature of 80℃, a spray pressure of 70kPa, a liquid pump speed of 10 mL / min, and a drying air flow rate of 39 m 3 Drying was carried out under conditions of / h.

[0062] Freeze-drying was performed by freezing the albumin solution at -78°C for 24 hours and then drying it using a freeze dryer (FD5508, Ilshin BioBase), and vacuum drying was performed by drying it for 48 hours at 60°C and 0.1 kPa using a vacuum oven (C-DVD3, Changshin Science Co., Ltd.).

[0064] Making meringue cookies

[0065] First, mix 10g of albumin powder, 90g of distilled water, and 10g of sugar, and use a KitchenAid mixer (KitchenAid Artisan ®After stirring uniformly for 2 minutes with (Whirlpool Corporation), an additional 20g of sugar was added and whipped at high speed for 8 minutes to prepare a meringue batter.

[0066] Next, the meringue batter was panned in an oven tray with a diameter of 45 mm and a height of 30 mm, and baked in an oven at 100°C for 90 minutes to produce the meringue cookies of Example 1 and Comparative Examples 1 and 2.

[0067] Meanwhile, a meringue dough was prepared by adding an equal amount of sugar to a raw material solution mixed with 71.4g of egg white solution and 28.6g of distilled water and stirring, and then baking it in an oven in the same manner as above to produce the meringue cookies of Control Group 1.

[0069] [Experimental Example 1]

[0070] The zeta potential of the albumin powder prepared in Preparation Example 1 was measured, and the surface hydrophobicity (H0) was measured, and the results are listed in Table 1.

[0071] Zeta potential was measured by preparing a 10-fold diluted solution by adding distilled water to each sample, and then using a Nano ZS90 Zetasizer (Malvern instruments Ltd.).

[0072] Surface hydrophobicity was evaluated by first dissolving the sample in sodium phosphate buffer (10 mM, pH 7) until the protein concentration was 0.02%, then sequentially diluting it to prepare solutions of 0.02%, 0.01%, 0.005%, 0.0025%, and 0%. Specifically, 150 µl of the above solution and 10 µl of 8.0 mM ANS solution were dispensed onto a black plate and reacted in the dark for 10 minutes, after which the plates were placed in a Multimode microplate reader (Thermo Scientific TM Varioskan TMUsing LUX, the fluorescence values ​​at an excitation wavelength of 390 nm and an emission wavelength of 470 nm were measured and plotted on a graph, and the slope of the graph was calculated to obtain the surface hydrophobicity value.

[0073] Zeta potential (mV) H0 Comparative Example 1 0.74±0.14 188.48±8.08 Comparative Example 2 -3.49±0.08 324.05±3.11 Example 1 -6.79±0.17 363.38±6.10

[0074] The zeta potential exhibits a larger negative value as protein damage decreases; it was observed that Comparative Example 1 showed a decrease in surface charge due to thermal aggregation, and Comparative Example 2 also showed slight protein damage. On the other hand, it was confirmed that there was almost no protein damage in Example 1. For the same reason, the surface hydrophobicity of Comparative Example 1 was low, while the surface hydrophobicity of Example 1 was the highest. Therefore, based on the results of this experiment, it was confirmed that applying the freeze-drying method is desirable to preserve the protein structure while minimizing or preventing protein damage during the preparation of albumin powder.

[0076] [Experimental Example 2]

[0077] Protein electrophoresis analysis of the albumin powder prepared in Preparation Example 1 was performed, and the results are shown in Figure 1.

[0078] As a result of the experiment, distinct bands corresponding mainly to globulin (75–80 kDa) and albumin (23–26 kDa) were observed, and in the case of Comparative Example 1, the globulin structure was fragmented into subunits, creating a distinct band at the bottom of the gel, which is a result of structural damage caused by high temperature during the drying process.

[0079] Therefore, the results of this experiment confirmed that it is desirable to apply a drying method that does not apply heat to maintain the structure of the protein.

[0081] [Experimental Example 3]

[0082] The foaming capacity and foaming stability of the albumin powder prepared in Preparation Example 1 were measured, and the results are shown in Figure 2.

[0083] Foaming ability and foam stability were calculated by mixing 3.3g of albumin powder with 30g of distilled water to prepare a sample, stirring it with an Ultra Turraxhomogenizer (IKA, Staufen) at 14,000 rpm for 1 minute to produce foam, transferring the generated foam to a graduated cylinder, and measuring the initial foam volume and the foam volume after 30 minutes three times, respectively. Foaming ability was calculated as the percentage of the initial foam volume to the volume of the solution before stirring, and foam stability was calculated as the percentage of the foam volume after 30 minutes to the initial foam volume.

[0084] As a result of the experiment, Example 1 showed excellent values ​​for both foam-forming ability and foam stability. This result was obtained because the structure of the albumin protein in Example 1 was stably preserved without damage; specifically, this is because the adsorption ability at the liquid-air interface was enhanced, leading to increased hydrophobicity and improved stability. It can be confirmed that these experimental results are consistent with the trends of Experimental Example 1 and Experimental Example 2.

[0085] Therefore, it was confirmed that adopting the freeze-drying method during the preparation of albumin powder is desirable to improve the foam-forming ability and foam stability of the egg white substitute.

[0087] [Experimental Example 3]

[0088] The color and hardness of the meringue cookies prepared in Preparation Example 1 were measured and listed in Table 2. Hardness was measured using a texture analyzer (TA.XT plus, Stable Micro Systems), color was measured using a colorimeter (CR-400 Konica Minolta Sensing, Inc), and the color difference (△E) with control group 1 was evaluated by calculating it using the following [Equation 1]. In [Equation 3], △L* represents the difference in brightness between control group 1 and the sample, △a* represents the difference in redness between control group 1 and the sample, and △b* represents the difference in yellowness between control group 1 and the sample.

[0089] [Formula 1]

[0090]

[0091] L* a* b* ΔE Hardness (g f ) Control group 1 71.70±0.87 0.67±0.33 21.31±0.37 - 142.00±9.44 Comparative Example 1 58.80±0.06 3.73±0.78 25.26±0.90 13.87±0.35 196.27±8.48 Comparative Example 2 78.68±0.58 -2.27±0.08 16.92±0.92 8.80±0.16 144.43±8.01 Example 1 74.78±0.23 -1.76±0.14 21.74±1.09 4.05±0.12 174.63±5.91

[0092] As a result of the experiment, Example 1 showed the lowest color difference from Control 1, and the Comparative Example and Example showed higher hardness than Control 1. This suggests that the surface layer of the meringue cookie using albumin powder forms a firmer protein network than that of the meringue cookie using egg white.

[0094] [Experimental Example 4]

[0095] The bulk specific density of each meringue dough prepared in Preparation Example 1 was measured and is shown in Fig. 3, and the apparent viscosity was measured and is shown in Fig. 4.

[0096] The secretion was calculated by placing the meringue batter in a calibrated container and measuring its weight, adding water to the calibrated container to measure its volume, and then calculating the secretion by dividing the weight of the meringue batter by the volume of the water.

[0097] Apparent viscosity was measured at 25°C using a rotational rheometer (RheoStress RS 1, HAAKE Instruments) equipped with a plate-plate geometry system for 0.1–100 s⁻¹. -1 It was measured by performing normal shear tests at various shear rates.

[0098] Generally, the lower the secretion, the more stable the characteristics of the protein foam. Experimental results showed that Comparative Example 2 and Comparative Example 1 had stable protein foam characteristics and were similar to Control 1. This is judged to be a result of the protein interactions being promoted due to the increase in surface hydrophobicity.

[0100] [Experimental Example 5]

[0101] The rheological properties of each meringue dough prepared in Preparation Example 1 were analyzed, and the storage coefficient (G') is shown in FIG. 5 and the loss coefficient (G'') is shown in FIG. 6.

[0102] Rheological properties were examined at 25°C using a rotational rheometer (RheoStress RS 1, HAAKE Instruments) equipped with a 20 mm plate-plate geometry system. The distance between the plate and the geometry was adjusted to 1 mm, and frequency sweep tests were performed at 1% strain to examine the frequency range of 0.1 to 10 Hz.

[0103] As a result of the experiment, all samples including control group 1 exhibited pseudo-plastic behavior, and the behavior of Example 1 and Comparative Example 2 was particularly more similar to control group 1, and the behavior of Example 1 was found to be most similar to the behavior of control group 1.

[0104] Therefore, it was confirmed that vacuum drying or freeze-drying is preferable when manufacturing albumin powder, and that freeze-drying is the most desirable method.

[0106] [Experimental Example 6]

[0107] The appearance of the meringue batter (dough) prepared in Preparation Example 1, the appearance and cross-section of the oven-baked meringue cookies were photographed and are shown in Fig. 7. In addition, the cross-section of each meringue cookie was observed under a microscope and is shown in Fig. 8.

[0108] Looking at the experimental results, in the case of Comparative Example 1, the meringue batter was in a liquid state, so it lacked external integrity and had an empty internal structure. In the case of Comparative Example 2, the appearance of the meringue batter or meringue cookie was similar to that of Control Group 1, but the thermal stability of the foam was poor, resulting in the formation of empty spaces inside the meringue cookie.

[0109] On the other hand, Example 1 showed a structure similar to Control 1, with the appearance of the meringue batter and meringue cookie intact and a dense air layer structure formed densely inside, as confirmed in the cross-sectional photograph of the meringue cookie. This structure of Example 1 is due to the formation of a high-density air structure caused by gradual protein binding, and from these experimental results, it was confirmed that it is desirable to apply the freeze-drying method as a drying method when manufacturing an egg white substitute containing plant-derived albumin for making meringue cookies.

[0111] [Preparation Example 2]

[0112] Preparation of albumin solution

[0113] After removing the hulls from cowpeas, they were minced to prepare a cowpea dough. The cowpea dough was mixed with water in a ratio of 1:5 (w / v) to prepare soy milk. A 1N NaOH aqueous solution was mixed in to adjust the pH of the soy milk to 8.5, and the mixture was stirred at 900 rpm for 1 hour to perform primary pH adjustment. The pH-adjusted soy milk was then centrifuged at 9,000 rpm for 25 minutes to obtain the supernatant. The pH was further adjusted by adding 1N HCl until the pH of the supernatant reached 5, and then centrifuged again (9,000 rpm, 15 minutes) to obtain the supernatant, thereby preparing an albumin solution. At this stage, various types of albumin solutions were prepared by adjusting the pH to 3, 4, 5, 6, and 7 during the secondary pH adjustment step.

[0115] Making meringue cookies

[0116] Mix 100g of albumin solution with 25g of sugar, then mix in an additional 25g of sugar, and then use a KitchenAid mixer (KitchenAid Artisan ® A meringue batter was prepared by whipping at high speed for 8 minutes using a Whirlpool Corporation.

[0117] Subsequently, meringue cookies were prepared using the same method as in Preparation Example 1, and as a control, a mixture of 25g of egg white solution and 75g of water was used as a substitute for albumin solution to prepare meringue batter and meringue cookies using the same method as above, and this was named Control 2.

[0119] [Experimental Example 7]

[0120] The composition of the albumin solution prepared in Preparation Example 2, in which the pH was adjusted to 5 during the second pH adjustment step, was analyzed, and the results are listed in Table 3.

[0121] furtherance(%) Ash crude fat crude protein carbohydrate Albumin solution (pH 5) 1.69±0.22 18.62±0.65 57.54±0.44 22.15±1.31

[0122] The protein content of the albumin solution was approximately 54%, and it was confirmed that it contained non-protein components that were not completely separated during the extraction process.

[0124] [Experimental Example 8]

[0125] The zeta potential of the albumin solution prepared in Preparation Example 2 was measured and is shown in Fig. 9, and the results of the electrophoretic analysis were performed and are shown in Fig. 10.

[0126] Experimental results showed that the isoelectric point of the albumin solution was approximately pH 4.1–4.3, and electrophoresis analysis revealed that bands corresponding to globulin (65–70 kDa) and albumin (23–26 kDa) were clearly visible regardless of pH changes. This implies that pH has minimal effect on the degradation and binding of protein structures.

[0128] [Experimental Example 9]

[0129] The color and hardness changes of the meringue cookies prepared in Preparation Example 2 were measured in the same manner as in Experimental Example 3, and the results are listed in Table 4.

[0130] L* a* b* ΔE Hardness (g f ) Control group 2 80.75±0.34 -1.59±0.06 10.08±0.59 - 411.83±17.93 pH 3 79.94±0.53 -1.55±0.06 6.80±0.39 3.41±0.40 692.00±35.53 pH 4 75.42±0.57 -1.34±0.14 5.21±0.64 7.26±0.31 343.50±16.89 pH 5 72.00±0.41 -1.20±0.17 3.57±0.39 10.92±0.51 267.40±14.53 pH 6 63.61±0.62 -1.09±0.09 3.64±0.32 18.32±0.48 672.47±21.37 pH 7 68.59±0.67 -1.09±0.11 5.43±0.26 13.03±0.55 743.77±16.05

[0131] As a result of the experiment, meringue cookies made using albumin solution showed lower L* and b* values ​​and higher a* values ​​compared to meringue cookies made using egg whites. Additionally, meringue cookies made with albumin solution had higher hardness compared to control group 2, except at pH 4 and 5. This is because, at pH 3, they hardened without forming a structure, while at pH 4 and 5, the hardness decreased due to the large air cell structure.

[0132] On the other hand, it was found that as the pH approaches neutrality, the air cell structure becomes smaller and denser, and the physical properties of the dough are well established, resulting in increased hardness.

[0134] [Experimental Example 10]

[0135] 30 mL of the albumin solution prepared in Preparation Example 2 was used as a sample, and foam-forming ability and foam stability were evaluated in the same manner as in Experimental Example 3, and the results are shown in Fig. 11.

[0136] In addition, the bulk specific density and apparent viscosity of each meringue dough prepared in Preparation Example 2 were measured using the same method as in Experimental Example 4, and the bulk specific density is shown in Fig. 12 and the apparent viscosity is shown in Fig. 13.

[0137] Experimental results confirmed that the lower the density of the dough, the better the foam-forming characteristics of the protein foam. The high density values ​​at pH 4 or lower are attributed to the absence of solid bubbles and low air incorporation due to the flow characteristics of the dough, while the increase in density at pH 5 or higher is considered to be the result of improved dough stability.

[0138] Meanwhile, as a result of measuring apparent viscosity, the meringue dough of the samples including control group 2 exhibited pseudoplastic behavior characterized by a decrease in viscosity within the shear rate range.

[0140] [Experimental Example 11]

[0141] The rheological properties of each meringue dough prepared in Preparation Example 2 were evaluated in the same manner as in Experimental Example 5, and the storage coefficient (G') and loss coefficient (G'') were shown in FIG. 14 and FIG. 15, respectively.

[0142] Experimental results showed that the storage factor increased as the pH level rose, and protein interactions also changed with pH variations; it was confirmed that as pH increased, the interaction strength and network formation were enhanced.

[0144] [Experimental Example 12]

[0145] The appearance of the meringue batter (dough) prepared in Preparation Example 2, the appearance and cross-section of the oven-baked meringue cookies were photographed and are shown in FIG. 16. In addition, the cross-section of each meringue cookie was observed under a microscope and is shown in FIG. 17.

[0146] As a result of the experiment, at pH 3 and 4 of the samples, the albumin solution lacked air, exhibiting behavior similar to a liquid, and the shape of the meringue cookies was not well maintained. However, from pH 5 and above, a firm texture was formed, and it was confirmed that the structural integrity of the meringue cookies was improved.

[0147] In particular, when the pH is 6 to 7, protein binding is strengthened, and the air cells inside the meringue cookie are formed densely and tightly, and it was confirmed that a dense air layer structure is formed.

[0148] Therefore, as a result of this experiment, it was confirmed that when preparing a protein solution, it is desirable to adjust the pH to 5 to 8, preferably 6 to 8, and more preferably 6 to 7.

[0149] The present invention is not limited to the specific embodiments and descriptions described above, and various modifications can be made by anyone with ordinary knowledge in the technical field to which the invention pertains without departing from the essence of the invention as claimed in the claims, and such modifications fall within the scope of protection of the present invention.

Claims

Claim 1 A method for manufacturing a plant-based egg white substitute comprising: a raw material manufacturing step of extracting albumin from cowpeas to prepare an albumin solution; and a drying step of freeze-drying the albumin solution; wherein the raw material manufacturing step comprises: a soy milk manufacturing step of mincing peeled soybeans and then mixing cowpeas and water in a weight and volume ratio (w / v) of 1:3 to 10 to prepare soy milk; a first pH adjustment step of adding a base to the soy milk and stirring to adjust the pH to a range of 7.5 to 9.5; a first separation step of centrifuging the pH-adjusted soy milk to separate the supernatant; a second pH adjustment step of adding an acid to the separated supernatant and stirring to adjust the pH to 6 to 7; and a second separation step of centrifuging the pH-adjusted protein mixture to collect the supernatant, which is the albumin solution. Claim 2 A method for manufacturing a plant-derived egg white substitute containing plant-derived albumin, wherein, in claim 1, the first separation step is performed at a speed of 1,000 to 20,000 rpm for 10 to 40 minutes, and the second separation step is performed at a speed of 1,000 to 20,000 rpm for 5 to 30 minutes. Claim 3 A method for manufacturing a plant-derived egg white substitute containing plant-derived albumin, characterized in that, in the first step, a grinding process and sieving for ensuring uniform particle size are additionally performed after the drying step. Claim 4 A method for producing meringue cookies using a plant-derived albumin substitute, comprising: a step of mixing and stirring water and sugar with a plant-derived albumin substitute produced by a manufacturing method according to any one of claims 1 to 3 to produce a meringue; a step of panning the meringue onto a tray; and a step of placing the tray on which the meringue batter is panned into an oven and baking it to produce a meringue cookie. Claim 5 A method for manufacturing meringue cookies using a plant-derived egg white substitute containing plant-derived albumin, wherein, in claim 4, the step of manufacturing meringue cookies in an oven is performed at 80 to 120°C for 70 to 120 minutes. Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete

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