Cake prepared by partially replacing egg white with microalgae and preparation method thereof

Abstract

The invention relates to a cake prepared by partially replacing egg white with microalgae and a preparation method thereof, and belongs to the technical field of deep processing of microalgae. The invention firstly provides application of microalgae slurry in the field of food instead of egg white. The microalgae slurry is liquid prepared by dissolving processed microalgae powder and water in a weight ratio of 1: 3 at room temperature for 30 minutes. The prepared novel microalgae powder has excellent stability, can be stored for a long time, has excellent foaming performance and good foam stability, and can be used as a functional substitute of egg white. According to the method, the additional value of microalgae resources is increased, an innovative thought is provided for development of plant-based products, and the application prospect of microalgae in the food industry is remarkably expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microalgae deep processing, and particularly relates to a cake prepared by partially replacing egg white with microalgae and a preparation method thereof. BACKGROUND

[0002] Microalgae are a class of aquatic autotrophic organisms with small individual and simple structure, which are widely distributed in the environment such as oceans, soils and lakes. Microalgae are rich in high-nutrition-value proteins (30%-70%) and carbohydrates, and the essential amino acid index of the proteins in microalgae is equivalent to that of meat proteins and soybean proteins. Meanwhile, the emulsification and foaming properties of the microalgae proteins are equivalent to those of whey proteins and soybean proteins, and the microalgae proteins have low allergenicity, which are potential high-quality protein sources. A large amount of bioactive substances contained in microalgae have important development value in the industries of food processing, preservation, health products and special health auxiliary foods. At the same time, microalgae become an ideal choice for sustainable food due to their efficient production mode, resource utilization efficiency, environmental friendliness and diversified application.

[0003] Egg white is a colloidal substance with water as a dispersion medium and proteins as a dispersed phase, in which the ratio of water to proteins is about 9:1, and the rest is a small amount of vitamins, lipids and minerals. Egg white is widely used in the baking field due to its good foaming, emulsifying and gelling properties, and the excellent foaming property of egg white is one of the most important reasons for the softness and elasticity of cakes. However, the four allergenic proteins in eggs are all main components of egg white, and egg white also has problems such as insufficient foam stability. Consumers, especially vegans, flexitarians and vegetarians, have reached a record high demand for high-quality functional plant substitutes, so it is particularly important to find egg white substitutes and develop green, nutritious and healthy baked foods. There are some egg white substitutes, such as flaxseed and chickpea water, which only have a sticky effect or need a long time to whip, and cannot replace the functional role of eggs. There are also plant proteins such as soybean protein and pea protein, which have good foaming properties but cannot produce highly stable foams.

[0004] Microalgae are rich in many nutrients, but it is difficult to release and absorb them by general food processing methods. The ultrahigh pressure microjet treatment can break the microalgae at a rate of 80%-88% in a short time, greatly improving the bioavailability of microalgae and removing the fishy smell. The broken microalgae not only have good foaming properties but also can produce stable foams. At the same time, microalgae have significant advantages in nutritional value, sustainability and environmental characteristics, and economic benefits, and are an important potential raw material for the development of future food industry. SUMMARY

[0005] The first technical problem to be solved by the present application is to improve the foaming performance of microalgae by a specific preparation method, and to replace egg white for making cakes.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: The microalgae powder is dissolved with water, treated by ultrahigh pressure microjet, and then the obtained solution is treated by centrifugation, and the processed microalgae powder is obtained by spray drying.

[0007] Specifically, the steps include: (1) Dissolve the microalgae powder in water at room temperature, and stir uniformly with a high-speed shearing homogenizer; (2) Introduce the solution obtained in step (1) into a high-pressure microjet device to break the cell wall of the microalgae powder; (3) Centrifuge the solution obtained in step (2) to obtain the supernatant solution after treatment; (4) Spray dry the supernatant solution after centrifugation to obtain the processed microalgae powder; Preferably, in step (1), the microalgae powder is the powder of Spirulina microalgae.

[0008] Further, in step (1), the mass ratio of the microalgae powder to water is 1:30.

[0009] Further, in step (1), the high-speed shearing homogenizer has a rotation speed of 10,000-15,000 rpm, and the stirring time is 1-3 min.

[0010] Preferably, in step (2), the homogenization pressure of the high-pressure microjet device is 130 Mpa, and the cycle number is 2.

[0011] Preferably, in step (3), the centrifugal speed is 8,000 g , and the centrifugal time is 10 min.

[0012] Preferably, in step (4), the inlet air temperature of the spray drying device is 208℃, and the outlet air temperature is 90℃.

[0013] The second technical problem to be solved by the present application is to provide a preparation method for preparing cakes by partially replacing egg white with microalgae slurry. Dissolve the processed microalgae powder in water for 30 min to obtain microalgae slurry, add egg white, and whip with a whipping machine at high speed, while adding an appropriate amount of sugar, to finally obtain a mixture 1; emulsify the edible oil and milk, add flour and stir to obtain a mixture 2; mix the mixture 1 and the mixture 2, form a cake batter, pour it into a mold, and bake in an oven to obtain the final product. (1) First, the processed microalgae powder is dissolved with water, mixed uniformly, and then placed for 30 min to fully dissolve the foaming substances, to prepare a microalgae slurry; (2) The microalgae slurry prepared in (1) is mixed with egg white, and the mixture is first whipped at high speed and then at medium speed using a eggbeater. White sugar is added during the whipping process to obtain mixture 1; (3) Milk is added to edible oil, stirred and emulsified, and then low-gluten flour is added and stirred with a silicone spatula to obtain mixture 2; (4) Mixture 1 and mixture 2 are mixed uniformly to form a cake batter (avoiding excessive stirring to cause defoaming), and the cake batter is poured into a mold that has been brushed with oil in advance and placed in a preheated oven for baking; (5) The temperature of the oven is set to 140℃, and the cake is baked at this temperature for 35 min, and then the temperature is adjusted to 150℃ for baking for 25 min to obtain the final product.

[0014] Preferably, in step (1), the mass ratio of the processed microalgae powder to water is 1:3.

[0015] Further, in step (2), the replacement ratio of the microalgae slurry to egg white is 15%.

[0016] Further, in step (2), the white sugar content is 15.7 wt%.

[0017] Preferably, in step (3), the milk content is 15.7 wt%, the edible oil content is 9.8 wt%, and the flour content is 19.6 wt%.

[0018] Compared with the existing technology, the advantages and innovations of the present application are as follows: (1) The microalgae used in the present application is spirulina, which is widely available and rich in water-soluble protein and has high digestibility, making it a super nutritious food for the future.

[0019] (2) The present application uses microalgae to partially replace egg white to prepare a cake. Compared with directly adding microalgae as a raw material to prepare a cake, the content of eggs in the preparation of the cake is reduced, which can provide data support for the future production of egg-free microalgae cakes. Compared with lentil flour, flaxseed, and other egg substitutes, the use of microalgae to partially replace egg white not only has the function of simple adhesion, but also has the functional properties of egg white, thereby ensuring the soft texture of the prepared cake and promoting the volume expansion of the cake. Compared with using plant protein or animal protein as an egg substitute, these egg substitutes involve complex processing procedures and expensive equipment during preparation. The egg white of the present application is replaced by microalgae powder, which is easier to obtain and has a simple preparation method, thereby saving production costs.

[0020] (3) The microalgae powder is broken wall treated in the application, the processed microalgae powder foam prepared has better properties, and the rich nutrient substances in the microalgae are fully released, the bioavailability is improved, and the digestion and absorption of the human body are promoted.

[0021] (4) The microalgae partially replaces egg white in the application, and the beating is carried out under various proportions, and good foaming property is obtained, and the foam produced by the method has stronger stability.

[0022] (5) The cake prepared by the application is delicious and nutritious, has the color of matcha, and has no obvious algae smell, and the taste is mellow. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to make the embodiments of the application or the technical solutions of the prior art clearer, the drawings needed to be used in the embodiments or the technical description will be further described below.

[0024] Figure 1 Effects of different treatment methods on foaming property and stability of spirulina powder.

[0025] Figure 2 Effects of different treatment methods on foam size distribution after spirulina powder is foamed.

[0026] Figure 3 Effects of different treatment methods on surface tension after spirulina powder is foamed.

[0027] Figure 4 Effects of different replacement ratios on foaming property and stability of egg white.

[0028] Figure 5 Effects of different replacement ratios on foam size distribution after egg white is foamed.

[0029] Figure 6 Effects of different replacement ratios on foam, cake batter and cake morphology.

[0030] Figure 7 Effects of different replacement ratios on batter specific gravity and cake specific volume. DETAILED DESCRIPTION

[0031] The application will be further specifically and specifically described below in combination with specific examples, but the embodiments of the application are not limited thereto, and for the process parameters not specially marked, the conventional technology can be referred to.

[0032] Example 1 The embodiment provides a preparation method of processed microalgae powder, and the specific steps are as follows: Fresh food-grade spirulina powder was dissolved in 30 times of pure water by mass ratio, and was mixed uniformly by a high-speed shearing homogenizer at a speed of 10000 rpm. The solution was introduced into a high-pressure micro-jet device, and was subjected to cell wall breaking treatment at 130 Mpa and 2 cycles of homogenization. The obtained solution was treated by centrifugation (8000 x g, 10 min) to obtain a supernatant solution after treatment. Finally, spray drying was performed at an inlet air temperature of 208 ℃ and an outlet air temperature of 90 ℃ to obtain processed microalgae powder. g

[0033] Example 2 The present example provides a method for preparing microalgae slurry, and the specific steps are as follows: Fresh food-grade spirulina powder was dissolved in 3 times of pure water by mass ratio, and was mixed uniformly by stirring to avoid clumping. The microalgae slurry was prepared by placing it at room temperature for 30 min.

[0034] Example 3 The present example provides a method for preparing a cake by partially replacing egg white with microalgae slurry, and the specific steps are as follows: (1) 12 g of microalgae slurry was poured into 68 g of egg white, and was stirred with a whipping machine. The stirring speed was high at the beginning and was changed to medium speed at the end. 32 g of white sugar was added in three portions during the stirring process. The stirring was continued until the foam stopped rising, and a mixture 1 was obtained.

[0035] (2) 32 mL of milk was added to 20 g of corn oil and was stirred to emulsify. 40 g of low-gluten flour was sieved twice and was mixed with the mixture by using a silicone spatula, and a mixture 2 was obtained.

[0036] (3) The mixture 1 and the mixture 2 were mixed, and the cake batter was prepared by slowly stirring. The cake batter was poured into a mold that was brushed with oil in advance, and was placed in a preheated oven at 140 ℃ for 35 min. The temperature was adjusted to 150 ℃ for 25 min. After baking, the cake was cooled and demolded, and a finished cake was obtained.

[0037] Comparative Example 1 The difference between the present comparative example and Example 3 is that the cake was prepared using whole egg white, and the other ingredients and processing steps were the same as those of Example 3.

[0038] By Figure 6 ​It can be seen that when the substitution rate is between 0~25%, the foam can form a smooth hook with lines, and when the substitution rate exceeds 25%, the foam is difficult to form a hook shape, showing a fluid state and unable to maintain its structure. From the cross-sectional view of each sample group, compared with the pure egg white group, increasing the egg white substitution rate makes the cake pore size more uniform and dense. The overall macrograph of the cake shows that a lower concentration substitution rate shows a larger cake volume, and when the substitution rate is greater than 15%, the cake volume has a tendency to shrink, and the higher the concentration, the smaller the volume, and with the increase of the substitution rate concentration, the color of the cake also changes from matcha green to grass green.

[0039] Experimental Example 1 The embodiment provides a method for determining the foaming property and foam stability.

[0040] The specific technical solution steps are as follows: Dissolve the processed microalgae powder in 100 times of pure water by mass ratio, place the dissolved algal liquid in a bottle, record the volume V1, homogenize the solution with a high-speed homogenizer for 3 min, record the volume V2, and record the volume V3 after placing the homogenized solution for 30 min. The calculation formula of foaming property and foaming stability is as follows: Foaming property (%) Stability (%)

[0041] Through Figure 1 It can be seen that the foaming property of the algal powder after centrifugal treatment is better than that of the algal powder without centrifugal treatment, wherein the centrifugal algal powder homogenized twice at 130 Mpa pressure and once at 200 Mpa pressure is the best; the foaming property of the high-purity phycocyanin is at the middle level of each sample group, which indicates that the foaming property of the extract with low purification degree may be better than that of the extract with high purification degree. Through Figure 1 It can be seen that the stability of each group has little difference, but the stability of the foam solution of each group is higher than 80%, which indicates that the active ingredients in spirulina can be adsorbed on the gas-water interface for a long time, and have good interfacial activity.

[0042] Experimental Example 2 The embodiment provides a method for determining the size of the bubble shape.

[0043] The specific technical solution steps are as follows: Observe and take photos of the foam solution homogenized by the high-speed homogenizer for 2 min and 30 min under the optical microscope with 4 times objective lens and 10 times ocular lens, and count the particle size and distribution of the foam of each group.

[0044] Through Figure 2(a) (c) It can be seen that, compared with the control group, the non-centrifugal group of algal powder solution produces more bubbles at t0, and the distribution is more uniform; at t 30 , the bubble size of all sample groups becomes larger, among which the control group has the largest bubble size and the lowest compactness, which shows that the micro-jet wall breaking treatment can make the bubble size tend to be compact and uniform, and to some extent, inhibit the merging and coarsening of the foam. By Figure 2 (b) It can be seen that the bubble size of each treatment group at t0 and t 30 is smaller than that of the control group, and the bubble distribution is uniform. Compared with the crude extract of spirulina, the high-purity phycocyanin has smaller change in foam size within 30 min, which shows that improving the purity of protein helps to improve the stability of foam.

[0045] Experimental Example 3 The embodiment provides a method for determining surface tension.

[0046] The specific technical solution steps are as follows: Mix the microalgae powder with water at a mass ratio of 1:500, vortex for 15 s, then use a syringe to suck an appropriate amount of algal liquid, and squeeze out a 7 μL droplet, and use a video optical contact angle instrument to record the change of surface tension value within 30 min.

[0047] It can be seen from Figure 3 (a) (b) that the sample groups treated by high-pressure micro-jet can effectively reduce the surface tension of the algal liquid, and Figure 3 (a) shows that in the non-centrifugal treatment group, 130 Mpa 3 times and 200 Mpa 1 time reduce the surface tension to a greater extent, and these two groups also show higher whipping performance, and Figure 3 (b) shows that in the centrifugal treatment group, 130 Mpa 2 times and 200 Mpa 1 time reduce the surface tension to a greater extent, and these two groups also show higher whipping performance. Generally speaking, the stronger the ability to reduce surface tension, the better the foaming effect.

[0048] Experimental Example 4 The embodiment provides a method for determining the foaming property and foam stability.

[0049] The specific technical solution steps are as follows: The microalgae slurry obtained by dissolving the processed microalgae powder subjected to wall breaking treatment at 130 Mpa and centrifugal treatment twice in 3 times of pure water by mass ratio is placed in a bottle after replacing egg white by 0%, 10%, 15%, 20%, 25%, 30%, 40%, and 50%, the volume V1 is recorded, the solution after homogenization by a high-speed homogenization emulsifier for 3 min is recorded as volume V2, and the volume V3 is recorded after the homogenized solution is placed for 30 min. The calculation formulae of foamability and foam stability are as follows: Foamability (%) Stability (%)

[0050] By Figure 4 It can be seen from (a) that the microalgae slurry is used to replace egg white at different ratios to whip the foam under the same adjustment, wherein the foamability is optimal at a replacement rate of 15%, and compared with whipping of pure egg white, the samples with a replacement rate of 15% to 30% can significantly improve the foamability of the solution. From Figure 4 It can be seen from (b) that compared with the control group, the foam stability of the sample group is significantly improved, and the higher the replacement rate, the better the stability, wherein the foam stability is best at a replacement rate of 50%, because the ratio of the slurry is higher, the viscosity of the whipped foam is high, and the high viscosity can hinder the drainage of the foam to improve the stability of the foam.

[0051] Experimental Example 5 The embodiment provides a method for determining the size of a bubble shape.

[0052] The specific technical solution steps are as follows: The microalgae slurry obtained by dissolving the processed microalgae powder subjected to wall breaking treatment at 130 Mpa and centrifugal treatment twice in 3 times of pure water by mass ratio is placed in a bottle after replacing egg white by 0%, 10%, 15%, 20%, 25%, 30%, 40%, and 50%, the volume V1 is recorded, the solution after homogenization by a high-speed homogenization emulsifier for 3 min is recorded as volume V2, and the volume V3 is recorded after the homogenized solution is placed for 30 min. The calculation formulae of foamability and foam stability are as follows:

[0053] By Figure 5 It can be seen from (a) that at t0, the foam diameter of the samples at different replacement rates is smaller than that of the control group, and it can be known from (b) that the foam shape whipped by pure egg white is irregular and of different sizes, while the foam shape whipped by the egg white solution replaced by the slurry at different ratios is spherical and uniformly distributed. It can be known from Figure 5 (a) (b) that at t 90At this time, the foam diameter of each sample group increased, which was the result of foam aging, but compared with pure egg white, the sample group had a smaller trend of foam coarsening. In the case of low replacement ratio, the appearance of the foam was mostly irregular, while with the increase of the replacement ratio, the appearance of the foam was well improved, the foam was spherical, the diameter was much smaller than that of the pure egg white group, and the bubble size was more uniform.

[0054] Experimental Example 6 The embodiment provides a method for measuring the specific gravity of cake batter and the specific volume of cake.

[0055] The specific technical solution steps are as follows: The mass of the flat-bottomed container is m0, the container is filled with ultrapure water, and the total mass of the container and the ultrapure water is recorded as m1. After the container is emptied, the batter is filled again, and the total mass of the container and the batter is recorded as m2. The specific volume of the batter is calculated according to the following formula: Specific gravity of batter (g / cm3) =

[0056] The specific gravity of the cake is measured by the millet replacement method. First, the mass of the cake is measured as m, then a layer of millet is placed in a cylindrical container, and then the cake is placed in the container. Slowly add millet around the cake until the height of the millet and the cake is level, record the total volume at this time as V0, and then remove the cake and record the volume of the millet as V1. The volume of the cake is V=V0-V1, and the specific gravity of the cake is calculated according to the following formula: Specific volume of cake (g / mL) =

[0057] By Figure 7 (a) It can be seen that the specific gravity of the batter decreases significantly when the concentration of the algal slurry is low, which indicates that the addition of spirulina powder can better maintain the bubbles. When the concentration continues to rise, the specific gravity of the batter continues to increase, and even exceeds that of the pure egg white group. This may be due to the high viscosity of the batter, which makes the batter very thick and has poor flowability, making it difficult to stretch and fold during stirring, thereby limiting the incorporation of bubbles during stirring, resulting in a decrease in the quality of the batter.

[0058] By Figure 7 (b) It can be seen that the specific volume of the cake is increased at a replacement rate of 10% and 15%, which indicates that a low replacement rate is beneficial to the retention of air in the cake after baking. When the replacement rate is greater than 15%, the specific gravity of the cake decreases significantly, and the specific volume of the cake is greater, indicating that the cake is more fluffy, and the specific volume of the cake is smaller, indicating that the cake is more solid.

[0059] The above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Modifications or equivalent replacements of the technical solutions of the present application without departing from the purpose and scope of the technical solutions of the present application should be covered within the protection scope of the claims of the present application.

Claims

1. Application of microalgae slurry instead of egg white in food field.

2. The microalgal paste according to claim 1, characterized in that, The microalgae slurry is a liquid prepared by dissolving microalgae powder with water at a weight ratio of 1:3 at room temperature for 30 min.

3. The microalgal paste according to claim 2, characterized in that, The preparation method of the processed microalgae powder is as follows: the raw material microalgae powder is dissolved with water at a mass ratio of 1:30, homogenized at a rotation speed of 10,000-15,000 rpm for 1-3 min using a high-speed shearing homogenizer, then introduced into a high-pressure microjet device and homogenized for 1-3 cycles at a homogenization pressure of 0-200 Mpa, the obtained solution is subjected to centrifugal treatment (8,000 x g, 10 min), and finally the prepared powder is spray dried at an air inlet temperature of 200-210 DEG C and an air outlet temperature of 85-90 DEG C. g , 10 min), and finally the prepared powder is spray dried at an air inlet temperature of 200-210 DEG C and an air outlet temperature of 85-90 DEG C.

4. The microalgal paste according to claim 2 or 3, characterized in that, The microalgae powder is powder of Spirulina microalgae.

5. The food of claim 1, wherein The food is a cake.

6. A cake partially replacing egg white with a microalgal paste, characterized in that, The microalgae slurry of claim 1 is used to partially replace egg white in the cake processing process, and the total amount of microalgae slurry accounts for 10-30% of the total amount of cake raw materials, other raw materials including 10-20% of white sugar, 15-20% of milk, 15-25% of flour, and 5-15% of edible oil (by mass).

7. The cake partially replacing egg white with microalgal paste according to claim 6, characterized by, When the microalgae slurry is used as an egg white substitute, the microalgae slurry accounts for 10-50% of the sum of the weight of the microalgae slurry and the egg white.

8. Process for the preparation of a cake according to claim 6 or 7, characterized in that, The method comprises the following steps: (1) The microalgae slurry is added to the egg white separated from the chicken eggs in different proportions, and the egg white is first whipped at high speed and then whipped at medium speed using an eggbeater, and white sugar is added during the whipping process to obtain a mixture 1; (2) The edible oil and milk are emulsified, and then the flour is added and stirred with a silicone spatula to obtain a mixture 2; (3) The mixture 1 and the mixture 2 are mixed uniformly to form a cake batter, the cake batter is poured into a mold brushed with oil in advance, and the cake is baked in a preheated oven until it is mature.

9. The method of claim 8, wherein, The baking temperature in step (3) is gradient heating, the first stage temperature is 120-150℃, and the baking time is 15-35 min; the second stage temperature is 155-180℃, and the baking time is 15-30 min.

10. The method of claim 9, wherein, In step (3), the cake batter should be avoided to be over-stirred to cause defoaming.

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