A method of preparing a protein-based gluten-free frozen cake supplement

Abstract

The application discloses a preparation method of a protein-supplemented gluten-free frozen cake and belongs to the technical field of food. The cake is prepared from the following raw materials in proportion by weight: egg liquid 120 parts, rice flour 55-100 parts, whey protein isolate 15-45 parts, egg white powder 9-30 parts, sugar powder 45 parts, milk 20 parts and baking powder 3 parts. The specific preparation steps mainly include egg liquid whipping, mixing and sieving, batter adjusting and mold filling, baking, and cooling and freezing storage. The preparation method of the protein-supplemented gluten-free frozen cake can improve the large pores in the cross section of the cake produced by a high proportion of whey protein isolate, improve the sensory properties and nutritional value of the gluten-free cake, inhibit the aging caused by starch recrystallization during the freezing and freezing storage of the cake, and improve the freezing and freezing storage stability of the frozen cake.

Description

Technical Field

[0001] This invention belongs to the field of food technology. More specifically, it relates to a method for preparing a gluten-free frozen cake with supplemental protein. Background Technology

[0002] With the popularization of the concept of gluten-free healthy eating, gluten-free diets have gradually become a regular necessity in recent years. Rice is rich in B vitamins, dietary fiber, and rice protein. Its essential amino acid composition is complete, and it has low allergenicity, offering benefits such as aiding digestion, strengthening the spleen and stomach, and maintaining blood sugar balance. Glutinous rice flour has a high proportion of starch and protein, with low amylose content and high amylopectin content (95%–100%), making it less prone to aging and suitable for processing into gluten-free foods. However, due to the lack of gluten, it has poor gas and water retention, easily causing instability in the protein network structure of food, resulting in cakes that are prone to collapse and have poor elasticity. Currently, the main methods for improving the quality of gluten-free foods are adding different food nutrients and food additives; or adding gluten-containing ingredients such as wheat gluten to improve cake texture, but this is not suitable for people with gluten allergies. Therefore, there is a need for a method to prepare gluten-free, additive-free, and high-quality frozen cakes. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a gluten-free cake with high freeze-life stability and supplemental protein. Using glutinous rice flour as the raw material, a high-ratio blend of whey protein isolate and egg white powder is added to improve the large air pockets in the cake cross-section caused by the high proportion of whey protein isolate, thereby enhancing the sensory characteristics and nutritional value of the gluten-free cake. It also inhibits the aging caused by starch recrystallization during freezing and storage, as well as the deterioration of the cake's sensory quality due to moisture migration and redistribution, thus improving the freeze-life stability of the frozen cake.

[0004] This invention combines whey protein isolate and egg white powder, which not only improves the sensory quality and nutritional value of gluten-free cakes but also enhances their stability during freezing. Utilizing the emulsifying properties of the protein powder itself, without the addition of other additives, it effectively cleans the label. This can create substantial commercial value and provide an innovative approach for the gluten-free frozen cake industry.

[0005] To address the above problems, this invention provides a method for preparing a gluten-free frozen cake supplemented with protein, comprising the following steps:

[0006] S1. Whipping the egg mixture: Whip the egg mixture, adding sugar in 2-3 batches during the whipping process to obtain whipped egg mixture;

[0007] S2. Mixing and sifting: Add milk to the beaten egg liquid and mix well to obtain egg liquid with milk. Then mix glutinous rice flour, whey protein isolate, egg white powder and baking powder, and sift them into the egg liquid with milk in 2-3 batches, mixing well to make a batter.

[0008] S3. Mixing and pouring the batter into the mold: Pour the batter into the mold and remove air bubbles;

[0009] S4. Baking: Preheat the oven and bake the mold containing the batter.

[0010] S5. Quick-freezing: Place the baked cake in -50 to -40℃ and quickly freeze for 0.5 to 1.5 hours to obtain a gluten-free frozen cake.

[0011] Furthermore, in step S1, the mass ratio of egg liquid to sugar is 120:40-50.

[0012] Furthermore, in step S1, the playing time is 5 to 10 minutes.

[0013] Furthermore, in step S2, the mass ratio of the whipped egg liquid to milk is 165:10-30.

[0014] Furthermore, in step S2, the mass ratio of glutinous rice flour to whey protein isolate is 55:5 to 40.

[0015] Furthermore, in step S2, the mass ratio of glutinous rice flour to egg white powder is 55:5 to 30.

[0016] Furthermore, in step S2, the mass ratio of glutinous rice flour to baking powder is 55:2-3.

[0017] Preferably, in step S2, the mass ratio of glutinous rice flour to whey protein isolate is 55:25-35.

[0018] Preferably, in step S2, the mass ratio of glutinous rice flour to egg white powder is 55:10-20.

[0019] More preferably, in step S2, the mass ratio of glutinous rice flour to whey protein isolate is 55:30.

[0020] More preferably, in step S2, the mass ratio of glutinous rice flour to egg white powder is 55:15.

[0021] Furthermore, in step S2, the mesh size of the sieve is 50-60 mesh.

[0022] Furthermore, in step S4, the baking temperature is 140–150°C and the baking time is 40–50 min.

[0023] This invention provides a gluten-free frozen cake with supplemental protein prepared according to the above method.

[0024] The beneficial effects of this invention are:

[0025] This invention is based on gluten-free glutinous rice flour, with the addition of a high proportion of whey protein isolate and egg white powder to meet the requirements of GB24154-2015 National Food Safety Standard "General Rules for Sports Nutrition Foods". It solves the problem of large air pockets in the cross-section of cakes caused by a high proportion of whey protein isolate; it utilizes the emulsifying properties of the protein powder itself, without the addition of other additives, thus cleaning the label; it inhibits starch retrogradation during freezing; it limits the migration of water molecules, improves its water retention capacity, and enhances the water holding capacity of the cake, resulting in a good taste and relatively stable sensory quality of the frozen cake after freezing. Attached Figure Description

[0026] Figure 1 Changes in cake hardness during freezing.

[0027] Figure 2 Cross-section of the cake.

[0028] Figure 3 Changes in the water content of the cake during frozen storage. Detailed Implementation

[0029] The following examples illustrate a method for preparing a gluten-free frozen cake with supplemental protein, further demonstrating the outstanding advantages and significant features of the present invention. However, the present invention is not limited to the examples.

[0030] The testing method is as follows:

[0031] 1. Cake Texture Determination: The middle slice of cake was cut into 3cm × 3cm × 1.5cm cubes for texture analysis. Experimental conditions were: TPA probe type P / 50; speeds before, during, and after testing were 3, 1, and 5 mm / s respectively; trigger force was 10g; strain was 30%.

[0032] 2. Sensory evaluation of the cake: After sealing and packaging, the cake was refrigerated in a constant temperature refrigerator at -18℃. Sensory evaluation of the cake was carried out at 0 days, 15 days and 30 days of storage.

[0033] 3. Cake aging enthalpy determination: Weigh approximately 10 mg of the thawed cake sample and place it in an aluminum DSC crucible. After sealing, perform DSC measurement. The test procedure is as follows: the heating range is 25–110℃, and the heating rate is 5℃ / min.

[0034] 4. Determination of Freezeable Water in Cake: Weigh approximately 10 mg of the thawed cake sample and place it in an aluminum DSC crucible. After sealing, perform DSC analysis. The test procedure is as follows: Cool the cake from 20°C to -40°C at a cooling rate of 5°C / min, hold for 5 min, then heat it back to 20°C at a rate of 5°C. Record the melting curve of the cake and calculate the enthalpy of crystallization (ΔH). Percentage of freezeable water (Wf) re The calculation formula is as follows:

[0035] W fre =ΔH / ΔH0 × 100%

[0036] Where: ΔH0: enthalpy of pure water, 334 J / g

[0037] 5. Determination of basic nutritional components

[0038] (1) Determination of ash content: The total ash content in the cake was determined according to the first method of the National Food Safety Standard GB5009.4-2016, "Determination of Ash Content in Food".

[0039] (2) Protein determination: The total protein in the cake was determined according to the Kjeldahl method of the first method in the National Food Safety Standard GB5009.5-2016, "Determination of Protein in Food".

[0040] (3) Fat determination: The fat content was determined according to the first method Soxhlet extraction method of the National Food Safety Standard GB5009.6-2016, "Determination of Fat in Food".

[0041] (4) Determination of carbohydrates: According to GB / Z 21922-2008 Basic Terminology of Food Nutritional Components 2.2.8 Subtraction calculation of carbohydrates.

[0042] Example 1

[0043] A method for preparing a gluten-free frozen cake supplemented with protein includes the following steps:

[0044] S1. Whipping the egg mixture: Place 120 portions of egg mixture in a dry instrument and whisk with an egg beater. Add 45 portions of powdered sugar evenly in three batches, 2 minutes each time, for a total of 6 minutes, to obtain the whipped egg mixture.

[0045] S2. Mixing and sifting: Add 20 parts milk to the beaten egg liquid and beat for 1 minute to mix it evenly. Then mix 55 parts glutinous rice flour, 36 parts whey protein isolate, 9 parts egg white powder and 3 parts baking powder evenly. Sift the mixture into the beaten egg liquid in three batches and beat for 2 minutes to get the batter.

[0046] S3. Mix the batter and pour it into the mold: Mix the batter evenly and stir until there are no powdery particles. Then quickly pour it into the mold, filling each mold with the same weight of batter (35g). Gently shake the mold a few times to remove air bubbles.

[0047] S4. Baking: Preheat the oven, then place the mold containing the batter into the oven and bake at 150℃ for 40 minutes to get the cake.

[0048] S5. Quick-freezing and freezing: Place the baked cake at -40℃ for quick freezing for 1 hour to obtain a gluten-free frozen cake, and then transfer it to -18℃ for storage.

[0049] Example 2

[0050] A method for preparing a gluten-free frozen cake with supplemental protein is carried out according to the steps of Example 1, except that the 36 parts whey protein isolate and 9 parts egg white powder in step S2 are replaced with 30 parts whey protein isolate and 15 parts egg white powder to obtain a gluten-free frozen cake.

[0051] Example 3

[0052] A method for preparing a gluten-free frozen cake with supplemental protein is carried out according to the steps of Example 1, except that the 36 parts whey protein isolate and 9 parts egg white powder in step S2 are replaced with 22.5 parts whey protein isolate and 22.5 parts egg white powder to obtain a gluten-free frozen cake.

[0053] Example 4

[0054] A method for preparing a gluten-free frozen cake with supplemental protein is carried out according to the steps of Example 1, except that the 36 parts whey protein isolate and 9 parts egg white powder in step S2 are replaced with 15 parts whey protein isolate and 30 parts egg white powder to obtain a gluten-free frozen cake.

[0055] Comparative Example 1

[0056] A method for preparing a gluten-free frozen cake with supplemental protein is carried out according to the steps of Example 1, except that 55 parts of glutinous rice flour, 36 parts of whey protein isolate and 9 parts of egg white powder in step S2 are replaced with 100 parts of glutinous rice flour to obtain a gluten-free frozen cake.

[0057] Comparative Example 2

[0058] A method for preparing a gluten-free frozen cake with supplemental protein is carried out according to the steps of Example 1, except that the 36 parts whey protein isolate and 9 parts egg white powder in step S2 are replaced with 45 parts whey protein isolate to obtain a gluten-free frozen cake.

[0059] The results are as follows:

[0060] The firmness of the cake core can reflect the freshness of the cake during storage. Figure 1 It can be seen that the hardness increases with the extension of freezing time. This is because the moisture content of the cake decreases during freezing, and the recrystallization of starch affects its hardness. Within the same freezing time, the hardness of Examples 1, 2, 3, 4, Comparative Example 1, and Comparative Example 2 increased by 10.67%, 18.31%, 18.33%, 18.61%, 84.86%, and 10.75%, respectively. This confirms that freezing accelerates the deterioration of cake quality, thus adversely affecting its quality. The addition of egg white powder to Examples 1 and Comparative Example 2 slowed the rate of increase in cake hardness.

[0061] Table 1 shows the changes in sensory evaluation of the cake during frozen storage. Sensory scores decreased with prolonged frozen storage. After high-temperature baking, the flavor of whey protein isolate and egg white powder became acceptable to consumers. After 30 days of frozen storage, Example 2 showed significantly higher scores than the control group in all six aspects: appearance, elasticity, texture, aroma, taste, and overall acceptability. Studies have shown that the foaming properties of whey protein isolate help cakes rise higher, have a larger specific volume, and a better appearance; egg white powder can improve the softness of cakes. In conclusion, in cake production, adding a certain proportion of compounded whey protein isolate and egg white powder can improve the stability of the meringue, thereby preventing the escape of CO2 produced by the leavening agent, making the cake more fluffy and elastic. Figure 2 The cross-sectional view of the cake shows that large air pockets exist in Example 1 and Comparative Example 2. After adding EWP, there are no large air pockets in Example 2, Example 3 and Example 4, indicating that adding EWP can improve the large air pocket phenomenon.

[0062] Table 2 shows the changes in the aging enthalpy of the cake during frozen storage. As the frozen storage time increases, starch retrogradation occurs, the starch structure is destroyed, water is released, and ultimately, the cake loses moisture; its softness decreases, causing it to become dry and hard, thus reducing its edible quality. The aging enthalpy of the cake gradually increases with prolonged frozen storage time, indicating that starch recrystallization occurs during storage. Comparing the aging enthalpy of the examples with the comparative examples, the addition of protein powder in the examples slows down the increase in aging enthalpy of the cake during frozen storage, thus slowing down the aging process.

[0063] Figure 3 The change in the freezerable water content of cakes during frozen storage was observed. The freezerable water content of each group of samples increased with prolonged frozen storage time. This may be because temperature fluctuations during frozen storage caused ice crystals to recrystallize, leading to the release of water molecules and thus increasing the freezerable water content. The freezerable water content of the samples in the embodiment was significantly lower than that in Comparative Example 1, indicating that protein powder can improve its binding ability with water, enhance the cake's water-holding capacity, and reduce the increase in freezerable water content.

[0064] Two cakes, Example 2 and Comparative Example 1, were selected for a comparison of their basic nutritional components. According to GB24154-2015 National Food Safety Standard "General Rules for Sports Nutrition Foods," (1) requirements for supplementary protein (solid): protein ≥ 15g / 100g, fat ≤ 15g / 100g; (2) requirements for energy-controlled partial meal replacements: the energy provided by protein accounts for 25-50% of the total energy of the product, and the energy provided by fat accounts for ≤ 25% of the total energy of the product. According to Table 3, the final improved supplementary protein cake had a protein content of 18.87g / 100g, a fat content of 4.47g / 100g, a carbohydrate content of 41.65g / 100g, and an energy content of 1194.24KJ. It met the requirements for supplementary protein: protein ≥ 15g / 100g, fat ≤ 15g / 100g; and also met the requirements for partial meal replacements: the energy provided by protein accounts for 26.86% of the total energy of the product, and the energy provided by fat accounts for 13.85% of the total energy of the product. As shown in Table 4, the microbial indicators of Example 3 were all within the limits of national standards after freezing.

[0065] In summary, the method of using whey protein isolate combined with egg white powder to prepare gluten-free frozen cakes with supplemental protein can better maintain the frozen storage stability of the cakes, reduce the damage to cake quality caused by freezing, and achieve high sensory quality. Among them, Example 2 showed the best sensory effects and the most stable freeze resistance.

[0066] Table 1. Changes in sensory evaluation of cakes during freezing.

[0067]

[0068]

[0069] Table 2. Changes in aging enthalpy of cakes during frozen storage.

[0070]

[0071] Table 3 Basic Nutritional Components

[0072]

[0073] Table 4. Microbial Detection in Example 2

[0074]

[0075] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a gluten-free frozen cake supplemented with protein, characterized in that, Includes the following steps: S1. Whipping the egg mixture: Whip the egg mixture, adding sugar in 2-3 batches during the whipping process to obtain whipped egg mixture; S2. Mixing and sifting: Add milk to the beaten egg mixture and mix well to obtain an egg mixture with milk. Then mix glutinous rice flour, whey protein isolate, egg white powder, and baking powder, and sift the mixture into the egg mixture with milk in 2-3 batches, mixing well to obtain a batter. The mass ratio of glutinous rice flour to whey protein isolate is 55:25-35; the mass ratio of glutinous rice flour to egg white powder is 55:10-20. S3. Mixing and pouring the batter into the mold: Pour the batter into the mold and remove air bubbles; S4. Baking: Preheat the oven and bake the mold containing the batter. S5. Quick-freezing: Place the baked cake at -50~-40 ℃ for quick freezing for 0.5~1.5 hours to obtain a gluten-free frozen cake.

2. The method according to claim 1, characterized in that, In step S1, the mass ratio of egg liquid to sugar is 120:40~50.

3. The method according to claim 1, characterized in that, In step S2, the mass ratio of the whipped egg liquid to milk is 165:10~30.

4. The method according to claim 1, characterized in that, In step S2, the mass ratio of glutinous rice flour to whey protein isolate is 55:30; the mass ratio of glutinous rice flour to egg white powder is 55:

15.

5. The method according to claim 1, characterized in that, In step S2, the sieve mesh size is 50-60 mesh.

6. The method according to claim 1, characterized in that, In step S4, the baking temperature is 140~150 ℃ and the time is 40~50 min.

7. A gluten-free frozen cake with supplemental protein prepared by the method according to any one of claims 1 to 6.

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