A meal replacement shake made of a glycosylation-modified walnut protein and a method of making the same

Abstract

This invention relates to a meal replacement shake made from glycosylated modified walnut protein and its preparation method, belonging to the field of food processing technology. The specific method is as follows: walnut meal powder is dissolved in pure water, polysaccharides are added and stirred evenly, and then a wet-heat glycosylation reaction is carried out to obtain a glycosylated modified walnut meal powder solution; the glycosylated modified walnut meal powder solution is mixed evenly with walnut oil, steviol glycosides, xanthan gum and pure water, and then emulsified to obtain a liquid meal replacement shake made from glycosylated modified walnut protein, which is then spray-dried to obtain the meal replacement shake made from glycosylated modified walnut protein. This invention realizes the high added value utilization of walnut meal, and the resulting product has a delicate and smooth texture, rich walnut flavor, balanced nutrition, stable quality, and convenient preparation, meeting the needs of modern consumers for healthy meal replacement foods.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and in particular relates to a meal replacement shake made from glycosylated modified walnut protein and its preparation method. Background Technology

[0002] Walnuts, as one of the world's four major dried fruits, have both medicinal and edible properties and outstanding nutritional value. Currently, walnut processing is centered on oil extraction, which produces a large amount of by-product walnut cake. Walnut cake contains more than 40% protein, mainly composed of gluten and globulin. It is also rich in various vitamins and minerals, making it a plant protein resource with stable source, excellent quality, and great development potential.

[0003] However, the resource utilization of walnut cake is still in its early stages. The vast majority of cake is used only as a feed additive or directly discarded, and a very small portion is used as a low-value food ingredient. This not only causes a large waste of high-quality plant protein resources, but also causes a certain degree of environmental burden, seriously restricting the high-value and green development of the entire walnut industry chain.

[0004] Natural walnut protein suffers from inherent functional defects such as poor solubility and weak emulsifying properties, making it difficult to directly apply to various food systems and greatly limiting its industrial application. Glycosylation modification (Maillard reaction) is a simple, green, safe, efficient, and controllable protein modification technology suitable for industrial production. Through the covalent bonding of amino groups in protein molecules with carbonyl groups in polysaccharides, it can significantly improve key functional properties of plant proteins such as solubility, emulsifying properties, and thermal stability. It has been successfully applied to the functional improvement of various plant proteins such as kidney bean protein and rice protein, providing a reliable technical solution to overcome the bottlenecks in the application of walnut protein.

[0005] With the improvement of national living standards and the acceleration of the pace of life, the incidence of chronic diseases such as obesity and diabetes caused by unreasonable dietary structure continues to rise. Consumers' dietary concepts are rapidly shifting from "satisfaction-oriented" to "health-oriented" and "nutritional-oriented," leading to a period of rapid development for convenient and functional meal replacement foods. However, most commercially available meal replacement shakes use animal protein or soy protein as their core ingredients, generally suffering from problems such as a single nutritional composition and serious homogenization of flavors. The research and development and market application of meal replacement products with walnut meal as the core ingredient are still in a blank state. Using walnut meal for meal replacement shake preparation after glycosylation modification can not only realize the high added value conversion of walnut processing by-products, but also enrich the nutritional dimensions of meal replacement products, increase the supply of plant protein, unsaturated fatty acids and dietary fiber, and highly meet the market's consumption demand for healthy, diverse and distinctive meal replacement foods.

[0006] Currently, there are no literature reports on the glycosylation modification of walnut meal powder using xylooligosaccharides as glycosyl donors and its systematic application in meal replacement shakes. Furthermore, a complete system for formula optimization, process parameter control, and reconstitution performance evaluation has not been established. Therefore, developing a glycosylated walnut protein meal replacement shake and its standardized preparation method is of significant economic and social value for improving the comprehensive utilization rate of walnut resources, promoting the quality and efficiency of the walnut industry, and enriching the variety of healthy meal replacement foods. Summary of the Invention

[0007] This invention proposes a meal replacement shake made from glycosylated modified walnut protein and its preparation method, aiming to solve the problems in the prior art where the functional defects of natural walnut protein lead to a rough texture and easy caking of meal replacement products, as well as the serious waste of walnut meal resources and low added value.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a glycosylated modified walnut protein meal replacement shake powder includes the following steps: (1) Dissolve walnut meal powder in pure water, add polysaccharide and stir well, then carry out a wet heat glycosylation reaction to obtain a glycosylated modified walnut meal powder solution; (2) The glycosylated modified walnut meal powder solution is mixed evenly with walnut oil, steviol glycosides, xanthan gum and pure water and then emulsified to obtain glycosylated modified walnut protein liquid meal replacement shake; (3) Spray dry the glycosylated modified walnut protein liquid meal replacement shake to obtain a meal replacement shake made of glycosylated modified walnut protein.

[0009] This invention first modifies walnut meal powder through wet-heat glycosylation using xylooligosaccharides as glycosyl donors, significantly improving the solubility, emulsifying activity, and emulsifying stability of walnut protein. Then, the modified walnut meal powder solution is mixed with walnut oil, steviol glycosides, and xanthan gum, and emulsified at high speed to obtain a liquid meal replacement shake. Further, the shake powder is prepared using a spray-drying process, and its optimal preparation conditions are determined. This invention achieves high-value utilization of walnut meal, resulting in a product with a delicate and smooth texture, rich walnut flavor, balanced nutrition, stable quality, and convenient preparation, meeting the needs of modern consumers for healthy meal replacement foods.

[0010] Furthermore, in step (1), the ratio of walnut meal powder to pure water is 3g:200mL.

[0011] Further, in step (1), the mass ratio of walnut meal powder to polysaccharide is 5:1; the polysaccharide is selected from natural inulin, β-glucan or xylooligosaccharide, preferably xylooligosaccharide.

[0012] Furthermore, in step (1), the temperature of the wet heat glycosylation reaction is 91°C and the time is 70 min.

[0013] Further, by mass percentage, the amount of each raw material used in step (2) is: 40-80 wt% glycosylated modified walnut meal powder solution, 2.5-12.5 wt% walnut oil, 0.004-0.02 wt% steviol glycosides, 0.05-0.25 wt% xanthan gum, and the remainder is pure water.

[0014] Furthermore, by mass percentage, the amount of each raw material used in step (2) is: 70-80% glycosylated modified walnut meal powder solution, 4.5-6.5% walnut oil, 0.004-0.008% steviol glycosides, 0.1-0.16% xanthan gum, and the remainder is pure water.

[0015] Furthermore, in step (2), the rotation speed during the emulsification process is 8000 rpm, and the emulsification time is 3 min.

[0016] Furthermore, in step (3), the parameters for spray drying are: air inlet temperature 185℃ and feed flow rate 25mL / min.

[0017] The present invention also provides a glycosylated modified walnut protein meal replacement shake powder prepared by the above preparation method.

[0018] The present invention also provides a method for preparing the above-mentioned glycosylated modified walnut protein meal replacement shake powder, specifically: adding water to the glycosylated modified walnut protein meal replacement shake powder and heating and stirring (vortexing).

[0019] Furthermore, the ratio of the glycosylated modified walnut protein meal replacement shake powder to water is 5g:20mL; the heating and stirring temperature is 50℃ and the time is 30s.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention systematically compared the glycosylation modification effects of three polysaccharides—natural inulin, β-glucan, and xylooligosaccharide—on walnut meal powder, determining xylooligosaccharide to be the optimal glycosyl donor. Modification improved the solubility, emulsifying activity, and emulsifying stability of walnut meal powder solutions, significantly enhancing the functional properties of walnut protein and resolving the limitation on its application in food systems.

[0021] 2. This invention uses glycosylated modified walnut meal powder as the main raw material to prepare meal replacement shakes, realizing the high added value utilization of walnut oil processing by-products, while enriching the nutritional composition of meal replacement shakes and increasing the content of plant protein, unsaturated fatty acids and dietary fiber.

[0022] 3. This invention uses xanthan gum as a thickener. Xanthan gum is a biological heteropolysaccharide that can act as an emulsifying stabilizer to increase the viscosity of the product. Xanthan gum also has strong antioxidant properties and good freezing and heating stability, ensuring that the product has a good state and texture.

[0023] 4. The present invention further prepares meal replacement shake powder through spray drying process, making it convenient to prepare, store and transport. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 The results show the effects of different types of polysaccharides in Examples 1-3 and Comparative Example 1 (without added polysaccharides) on the solubility of walnut meal powder. Figure 2 The results show the effects of different types of polysaccharides in Examples 1-3 and Comparative Example 1 (without added polysaccharides) on the emulsifying activity and emulsifying stability of walnut meal powder. Figure 3 The effects of different amounts of glycosylated modified walnut meal powder solution added in Examples 4-8 on the sensory evaluation results of meal replacement shakes; Figure 4 The effect of different walnut oil addition amounts on the sensory evaluation results of meal replacement shakes in Examples 9-13; Figure 5 The effects of different amounts of steviol glycosides added in Examples 14-17 and Comparative Example 2 (without steviol glycosides) on the sensory evaluation results of the meal replacement shakes; Figure 6 The effect of different xanthan gum addition amounts on the sensory evaluation results of meal replacement shakes in Examples 1, 18-21; Figure 7 The effect of the amount of glycosylated modified walnut meal powder solution (A) and the amount of walnut oil (B) added on the sensory evaluation results of meal replacement shakes; Figure 8 The effects of walnut oil addition (B) and steviol glycoside addition (C) on the sensory evaluation results of meal replacement shakes; Figure 9 The effects of walnut oil addition (B) and xanthan gum addition (D) on the sensory evaluation results of meal replacement shakes; Figure 10 To illustrate the effect of different mixing temperatures on the sensory evaluation results of meal replacement shakes in Examples 1-5; Figure 11 The effect of different amounts of water used for mixing on the sensory evaluation results of meal replacement shakes in Application Examples 1 and 6-10. Detailed Implementation

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0030] This invention provides a method for preparing glycosylated modified walnut protein meal replacement shake powder, comprising the following steps: (1) Weigh walnut meal powder and pure water at a ratio of 3g:200mL. Dissolve the walnut meal powder completely in the pure water and stir evenly. Add polysaccharide at a mass ratio of walnut meal powder:polysaccharide of 5:1 and stir thoroughly until the system is uniform. Place the mixture at 91℃ for wet heat glycosylation reaction for 70min. After the reaction, a glycosylated modified walnut meal powder solution is obtained. The polysaccharide is selected from natural inulin, β-glucan or xylooligosaccharide, with xylooligosaccharide being preferred. (2) Weigh the glycosylated modified walnut meal powder solution, walnut oil, steviol glycosides, xanthan gum and pure water, mix them evenly, and emulsify them at 8000 rpm for 3 min to obtain glycosylated modified walnut protein liquid meal replacement milkshake. In the following optional embodiments of the present invention, based on a total weight of 100g of meal replacement shake, the amounts of each ingredient are: 40-80wt% glycosylated modified walnut meal powder solution, 2.5-12.5wt% walnut oil, 0.004-0.02wt% steviol glycosides, 0.05-0.25wt% xanthan gum, and the balance being pure water; preferably, based on a total weight of 100g of meal replacement shake, the amounts of each ingredient are: 70-80wt% sugar... The meal replacement shake contains 80 wt% glycosylated modified walnut meal powder solution, 4.5–6.5 wt% walnut oil, 0.004–0.008 wt% steviol glycosides, 0.1–0.16 wt% xanthan gum, and the balance being pure water; more preferably, based on a total weight of 100 g of meal replacement shake, the amounts of each ingredient are: 80 wt% glycosylated modified walnut meal powder solution, 5 wt% walnut oil, 0.005 wt% steviol glycosides, 0.1 wt% xanthan gum, and the balance being pure water. (3) The liquid milkshake was spray-dried, with the air inlet temperature controlled at 185℃ and the feed flow rate at 25mL / min. After drying, glycosylated modified walnut protein meal replacement milkshake powder was obtained.

[0031] A glycosylated modified walnut protein meal replacement shake powder can be prepared using the above preparation method. The specific method for preparing this glycosylated modified walnut protein meal replacement shake powder is as follows: Add water at a temperature of 40–80°C (e.g., 40°C, 50°C, 60°C, 70°C, 80°C, preferably 50°C) to the glycosylated modified walnut protein meal replacement shake powder at a material-to-liquid ratio of 5g:(15–35)mL (e.g., 5g:15mL, 5g:20mL, 5g:25mL, 5g:30mL, 5g:35mL, preferably 5g:20mL), and vortex for 30 seconds to mix evenly.

[0032] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0033] The technical solution of the present invention will be further illustrated by the following embodiments.

[0034] The walnut meal powder used in the following embodiments of the present invention is subcritical defatted walnut meal powder, purchased from Kashgar Guanghua Modern Agriculture Co., Ltd. Natural inulin was purchased from Fengning Ping An High-Tech Industry Co., Ltd.; β-glucan was purchased from Guangzhou Zhongkang Food Co., Ltd.; and xylooligosaccharides were purchased from Shandong Longli Biotechnology Co., Ltd.

[0035] Example 1 A method for preparing a glycosylated modified walnut protein meal replacement shake powder includes the following steps: (1) Weigh 3.00g of walnut meal powder, dissolve it completely in 200mL of pure water, add 0.60g of xylooligosaccharide, and stir thoroughly until the system is uniform; place the mixture at 91℃ for wet heat glycosylation reaction for 70min, and obtain glycosylated modified walnut meal powder solution after the reaction is completed; (2) After mixing the obtained glycosylated modified walnut meal powder solution, walnut oil, steviol glycosides, xanthan gum and pure water evenly, emulsify at 8000 rpm for 3 min to obtain glycosylated modified walnut protein liquid meal replacement shake; wherein, based on a total mass of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.1wt% xanthan gum, and the remainder pure water are added in sequence. (3) The liquid milkshake was spray-dried, with the air inlet temperature controlled at 185℃ and the feed flow rate at 25mL / min. After drying, glycosylated modified walnut protein meal replacement milkshake powder was obtained.

[0036] Example 2 Same as Example 1, except that the xylooligosaccharides in step (1) are replaced with natural inulin.

[0037] Example 3 Same as Example 1, except that xylooligosaccharides in step (1) are replaced by β-glucan.

[0038] Example 4 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 40wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0039] Example 5 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 50wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0040] Example 6 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 60wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0041] Example 7 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 70wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0042] Example 8 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0043] Example 9 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 2.5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0044] Example 10 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0045] Example 11 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 7.5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0046] Example 12 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 10wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0047] Example 13 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 12.5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0048] Example 14 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0049] Example 15 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.01wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0050] Example 16 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.015wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0051] Example 17 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.02wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0052] Example 18 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.05wt% xanthan gum, and the remainder is pure water.

[0053] Example 19 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.15wt% xanthan gum, and the remainder is pure water.

[0054] Example 20 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.2wt% xanthan gum, and the remainder is pure water.

[0055] Example 21 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.005wt% steviol glycosides, 0.25wt% xanthan gum, and the remainder is pure water.

[0056] Comparative Example 1 Same as Example 1, except that no polysaccharide was added in step (1).

[0057] Comparative Example 2 Same as Example 1, except that in step (2), based on a total weight of 100g of meal replacement shake, 80wt% glycosylated modified walnut meal powder solution, 5wt% walnut oil, 0.15wt% xanthan gum, and the remainder is pure water.

[0058] Test 1: 1. Solubility Specific determination method: Measure 1 mL of each glycosylated modified walnut meal powder solution and place them in a centrifuge tube. Prepare a dilution system by adding deionized water at a ratio of 1:9 (v / v). Take 1 mL of the diluted sample, let it stand for 20 min, and then measure the absorbance at 595 nm. Record the protein content in the solution. Centrifuge the remaining solution for 15 min at 8000 rpm and collect the supernatant. Take 1 mL of the supernatant and 5 mL of Coomassie Brilliant Blue in a test tube, vortex to mix, and measure the absorbance at 595 nm after 3 min. Use the sample without added polysaccharides as the control group (Comparative Example 1). Calculate the solubility using the following formula: ; In the formula: C0 is the protein content of the supernatant; C1 is the protein content of the solution.

[0059] Figure 1 The figures show the effects of different types of polysaccharides in Examples 1-3 and Comparative Example 1 (without polysaccharides) on the solubility of walnut meal powder. As can be seen from the figures, all three sugars (natural inulin, xylooligosaccharides, and β-glucan) improved the solubility of walnut meal powder. This is attributed to the formation of glycosylated conjugates, which introduces hydrophilic hydroxyl groups into the polysaccharides, enhancing the interaction between proteins and water molecules. Simultaneously, the steric effect of polysaccharides on proteins prevents aggregation between protein molecules, thereby increasing solubility. Xylooligosaccharides had the greatest impact on the solubility of walnut meal powder, reaching 67.71%, followed by natural inulin and β-glucan. At the same addition amount, sugars with smaller molecular weights introduce more hydrophilic hydroxyl groups into the system. Xylooligosaccharides have a relatively smaller molecular weight compared to the other two sugars, thus providing more hydrophilic groups and further enhancing their affinity for water molecules. Furthermore, xylooligosaccharides are extremely low in calories and resistant to acid and heat, making them suitable for diabetics and high-temperature processing. Therefore, xylooligosaccharides were selected as the glycosyl donor in subsequent experiments.

[0060] 2. Emulsifying Activity (EAI) and Emulsifying Stability (ESI) Specific determination method: Take 6 mL of glycosylated modified walnut meal powder solution, add 2 mL of walnut oil, homogenize at 8000 r / min for 3 min, immediately transfer 50 μL of sample from the bottom of the solution, add 5 mL of SDS (0.1%, w / v) solution, vortex for 5 s, and measure the absorbance value of the sample at 500 nm. After the emulsion is placed at room temperature for 10 min, repeat the above sampling and detection procedure. Use the sample without added polysaccharides as the control group (Comparative Example 1), and record the absorbance value after standing. The formula is as follows: In the formula: D F c is the dilution factor (100); c is the sample concentration (g / mL). ϕ For the optical path (1cm); The dispersion coefficient of the oil phase in the emulsion is 0.25; A0 and A 10 These represent the absorbance values ​​of the sample at the initial time of 0 min and after 10 min of rest, respectively.

[0061] Figure 2 The figures show the effects of different types of polysaccharides in Examples 1-3 and Comparative Example 1 (without polysaccharides) on the emulsifying activity and stability of walnut meal powder. As can be seen from the figures, all three sugars improved the emulsifying activity and stability of walnut meal powder. This is because natural inulin, xylooligosaccharides, and β-glucan are all hydrophilic polysaccharides, and hydrophilic sugars can enhance emulsifying activity. Among them, xylooligosaccharides showed the best emulsifying activity and stability of the walnut meal powder solution, reaching 87.13%. The improved emulsifying activity may be due to the glycosylation reaction causing a large number of protein molecules to be rapidly adsorbed at the oil-water interface, exposing the hydrophobic groups inside the walnut protein, reducing the interfacial tension of the system, and thus enhancing the surface activity of the protein. Furthermore, the interfacial affinity of the protein and the strong hydrophilicity of the polysaccharides have a synergistic effect between molecules, which can promote the formation of a strong solvation layer at the oil-water interface, thereby achieving good stability in the oil droplet space of the emulsion. Therefore, xylooligosaccharides were selected as the glycosyl donor in subsequent experiments.

[0062] 3. Sensory evaluation The specific method is as follows: The sensory evaluation panel consisted of 10 randomly selected individuals (5 men and 5 women) with some sensory evaluation experience. Before the evaluation, the panel members received brief training to ensure the consistency and accuracy of the evaluation results. The panel members evaluated randomly numbered milkshake samples in turn, focusing on four main aspects: color, aroma, taste, and texture. Specific evaluation criteria are shown in Table 1.

[0063] Table 1. Sensory evaluation scoring criteria for glycosylated modified walnut protein meal replacement shake powder Figure 3 The graph illustrates the effect of different amounts of glycosylated modified walnut meal powder solution added in Examples 4-8 on the sensory evaluation results of meal replacement shakes. As can be seen from the graph, the sensory score gradually increases with the increase of the amount of glycosylated modified walnut meal powder solution added. When the amount of glycosylated modified walnut meal powder solution added is low, the meal replacement shake is light in color, has some residue clinging to the sides, feels oily, has a weak walnut aroma, and exhibits slight layering after standing. When the amount of glycosylated modified walnut meal powder solution added reaches 80%, the walnut aroma is strong, the color is distinctly walnut-like and darker, and there is no layering, thus achieving the highest sensory score.

[0064] Figure 4 The graph illustrates the effect of different walnut oil addition amounts on the sensory evaluation results of meal replacement shakes in Examples 9-13. As can be seen from the graph, the sensory scores of the meal replacement shakes initially increased and then decreased with increasing walnut oil addition. Because the rich walnut aroma of walnut oil effectively highlights the flavor of the meal replacement shake, as the amount of walnut oil gradually increased, the shake became oily, the walnut oil flavor became overly prominent, and fat floated to the top. When the walnut oil addition was 5%, the walnut protein meal replacement shake had a suitable walnut aroma, did not separate into layers, and thus achieved the highest sensory score.

[0065] Figure 5 The graph illustrates the effects of different amounts of steviol glycosides added in Examples 14-17 and Comparative Example 2 (without steviol glycosides) on the sensory evaluation results of the meal replacement shakes. As can be seen from the graph, the sensory score of the meal replacement shakes initially increases and then decreases with increasing steviol glycoside content. Steviol glycosides, as a natural sweetener, are highly sweet, approximately 200-400 times sweeter than sucrose. When the amount of steviol glycosides added is high, the walnut protein meal replacement shake becomes overly sweet and cloying, making the walnut aroma less pronounced and failing to neutralize the flavor of the walnut. The optimal sweetness is achieved when the amount of steviol glycosides added is 0.005%, resulting in the highest sensory score.

[0066] Figure 6 The graph illustrates the effect of different xanthan gum addition amounts on the sensory evaluation results of meal replacement shakes in Examples 1 and 18-21. As can be seen from the graph, the sensory score of the meal replacement shake initially increases and then decreases with increasing xanthan gum addition. Insufficient xanthan gum results in a low overall viscosity, while excessive xanthan gum leads to an excessively high viscosity. When the xanthan gum addition amount is 0.15%, the walnut protein meal replacement shake exhibits a moderate overall viscosity, thus achieving the highest sensory score.

[0067] 4. Response surface methodology Through the above single-factor experiments, reasonable factor levels (60%, 70%, and 80% for the addition of glycosylated modified walnut meal powder solution; 2.5%, 5%, and 7.5% for the addition of walnut oil; 0%, 0.005%, and 0.01% for the addition of steviol glycosides; and 0.1%, 0.15%, and 0.2% for the addition of xanthan gum) were selected for response surface methodology. The results of the response surface methodology are shown in Table 2.

[0068] Table 2 Experimental Design and Results The quaternary quadratic regression equation for the sensory score of the walnut protein meal replacement shake was obtained using Design Expert 13: Y = 84.44 + 2.425A - 1.16667B + 0.566667C - 0.458333D - 3.675AB + 1.675AC + 0.175AD - 0.9BC + 0.975BD + 2.775CD - 1.22A 2 -8.2075B 2 -2.3075C 2 -1.12D 2 From this equation, we know that the quadratic term A 2 B 2 C 2 and D 2 The coefficients are all negative, indicating that the equation has a maximum value. Analysis of variance was performed on the response values ​​of 29 experimental points using DesignExpert software, and the results are shown in Table 3.

[0069] Table 3. Analysis of Variance for Quadratic Polynomials Note: A represents the amount of glycosylated modified walnut meal powder solution added; B represents the amount of walnut oil added; C represents the amount of steviol glycosides added; D represents the amount of xanthan gum added.

[0070] Figure 7 The effects of the addition amount of glycosylated modified walnut meal powder solution (A) and walnut oil (B) on the sensory evaluation results of meal replacement shakes were investigated. The figure shows a significant interaction between the addition amounts of glycosylated modified walnut meal powder solution and walnut oil. Considering only the interaction, higher sensory scores were achieved when the addition amount of glycosylated walnut meal powder solution was 70–80% and the addition amount of walnut oil was 4.5–6.5%.

[0071] Figure 8The effects of walnut oil (B) and steviol glycoside (C) additions on the sensory evaluation results of meal replacement shakes were investigated. The figure shows a significant interaction between the two. Considering only the interaction, higher sensory scores were achieved when walnut oil additions were between 4.5% and 6.5% and steviol glycoside additions were between 0.004% and 0.008%.

[0072] Figure 9 The effects of walnut oil (B) and xanthan gum (D) added on the sensory evaluation results of meal replacement shakes were investigated. The figure shows a significant interaction between the two additives. Considering only the interaction, higher sensory scores were achieved when the walnut oil content was 4.5–6.5% and the xanthan gum content was 0.1–0.16%.

[0073] Based on the experimental results, the optimal formula for walnut protein meal replacement shakes was obtained by processing the experimental data and results using Design Expert 13 software: 80% glycosylated modified walnut meal powder solution, 5% walnut oil, 0.005% steviol glycosides, and 0.1% xanthan gum. Under these conditions, the sensory score of the walnut protein meal replacement shake was 84.81. Three parallel experiments were conducted under these conditions, and the average comprehensive sensory score was 85.4, close to the theoretical value of 84.81, indicating that the obtained response surface model is reliable.

[0074] Application Example 1 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 50℃, vortex for 30s to mix evenly, and the preparation is complete.

[0075] Application Example 2 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 40℃, vortex for 30s to mix evenly, and the preparation is complete.

[0076] Application Example 3 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0077] Application Example 4 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 70℃, vortex for 30s to mix evenly, and the preparation is complete.

[0078] Application Example 5 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 80℃, vortex for 30s to mix evenly, and the preparation is complete.

[0079] Application Example 6 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 15mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0080] Application Example 7 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 20mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0081] Application Example 8 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 25mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0082] Application Example 9 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 30mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0083] Application Example 10 Take 5g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add 35mL of pure water at 60℃, vortex for 30s to mix evenly, and the preparation is complete.

[0084] Test 2: 1. Sensory testing The specific method is as follows: Ten people with certain sensory evaluation experience were selected to conduct sensory evaluation of the meal replacement shake powder. Before the evaluation, a simple training on the preparation knowledge of meal replacement powder and sensory evaluation was conducted to ensure the consistency and accuracy of the evaluation results. Then, the walnut protein meal replacement shake powder was analyzed and evaluated based on its reconstitution properties, texture, flavor, taste and mouthfeel, and color. The specific details are shown in Table 4.

[0085] Table 4. Sensory evaluation scoring table for prepared glycosylated walnut protein meal replacement shake powder. Figure 10To illustrate the effect of different mixing temperatures on the sensory evaluation results of meal replacement shakes in Examples 1-5, the graph shows that as the mixing temperature increases, the clumping of the meal replacement shake powder becomes more pronounced. Furthermore, the color of the mixed meal replacement shake powder darkens, and the walnut aroma fades, which may be due to the Maillard reaction between high temperatures and xylooligosaccharides. The optimal mixing temperature for the meal replacement shake powder is 50℃, at which point the walnut protein meal replacement shake powder dissolves completely, preserving the natural aroma of walnuts and thus achieving the highest sensory score.

[0086] Figure 11 The graph illustrates the effect of different water volumes on the sensory evaluation results of meal replacement shakes in Application Examples 1 and 6-10. As can be seen from the graph, increasing the water volume increases the contact opportunities between the meal replacement shake powder and water molecules, thereby improving its solubility and reducing clumping. When the water volume reaches 20 mL, the meal replacement shake powder exhibits a uniform color, suitable viscosity, rich taste, optimal sweetness, good solubility, and no clumping or graininess, thus achieving the highest sensory score.

[0087] 2. Agglomeration rate The determination method is as follows: Accurately weigh 5.00g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, and mix it at 50℃ with 20mL of water, stirring thoroughly. Filter the mixture through a 0.85mm sieve, rinse the clumps with water, and then dry it at 105℃ until constant weight. Weigh the mass of the dried residue and calculate the clumping rate according to the following formula: ; In the formula: m1 is the mass of the clump (g); m is the dry weight of the walnut protein meal replacement shake (g).

[0088] Clumping rate can be used to assess the physical stability and reconstitution properties of walnut protein meal replacement shake powder. The lower the clumping rate of the solid beverage, the better its reconstitution properties. The results are shown in Table 5.

[0089] Table 5 Results of mixing characteristics measurement As shown in Table 5, the clumping rate of the meal replacement shake powder prepared in Example 1 after reconstitution was 15.73%, indicating that it is not prone to clumping or layering and has good reconstitution properties. From the perspective of the formation mechanism, the low clumping rate may be due to the fact that the glycosylation modification of xylooligosaccharides significantly improved the hydrophilicity of walnut protein, introduced a large number of hydroxyl groups on the surface of protein molecules, and reduced the aggregation of protein particles caused by hydrophobic interactions.

[0090] 3. Wetting and sinking properties The determination method is as follows: 5.00g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1 was added to a beaker and evenly dispersed on the water surface. The time taken for the sample to completely wet and settle was recorded under both room temperature standing and magnetic stirring conditions. Wetting and settling properties reflect the dissolution rate and uniformity of the walnut protein meal replacement shake powder in the liquid. Measuring this index can determine whether the walnut protein meal replacement shake powder can dissolve quickly and completely in water or other liquids to form a uniform suspension or solution, which is crucial for the product's reconstitution and taste. The results are shown in Table 5.

[0091] As can be seen from Table 5, the meal replacement shake powder prepared in Example 1, after being mixed, took 86 seconds and 14 seconds to be completely wetted and settled under two conditions: room temperature standing and magnetic stirring. This indicates that the meal replacement powder has a relatively fast wetting and settling rate.

[0092] 4. Bulk density Determination method: Accurately weigh 5.00 g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, add it to a 25 mL graduated cylinder, vortex for 1 min, and record the graduations (V) on the graduated cylinder. M is the sample mass (g). Calculate the bulk density according to the following formula: Bulk density is one of the important indicators for measuring the stability of powder. Based on the bulk density, the required packaging volume for a certain weight of meal replacement powder can be accurately calculated, and the rational selection of packaging materials and specifications can help estimate transportation costs and transportation space. The results are shown in Table 5.

[0093] As can be seen from Table 5, the bulk density of the meal replacement shake powder prepared in Example 1 after reconstitution is 0.28 g / mL. This indicates that the meal replacement shake powder prepared by the present invention has low costs in terms of packaging and transportation, and can effectively reduce production and processing costs.

[0094] 5. Determination of dispersibility Test method: 5g of meal replacement shake powder (glycosylated modified walnut protein meal replacement shake powder prepared in Example 1) was added to a beaker placed on a magnetic stirrer at 50℃ with 20mL of water. The time taken for the meal replacement shake powder to completely disperse in water was recorded. This time is the dispersion time, which reflects the dispersibility of the walnut protein meal replacement shake. The shorter the dispersion time, the better the dispersibility. The results are shown in Table 5.

[0095] As can be seen from Table 5, the dispersion time of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1 after reconstitution is 31s, which indicates poor dispersibility and needs further improvement.

[0096] 6. Determination of solubility Determination method: Add 20 mL of water at 50℃ to a beaker, accurately weigh 5 g of the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1, and evenly disperse it in the beaker. Stir in a water bath at the optimal mixing temperature for 5 min, then centrifuge at 5000 rpm for 5 min. Take 15 mL of the supernatant, dry it at 105℃ to constant weight, and weigh the residue (m1). M2 is the initial total mass (g) of the glycosylated modified walnut protein meal replacement shake powder sample. The calculation formula is as follows: ; The higher the solubility of the meal replacement powder, the faster it dissolves, and the more uniform and delicate the dissolved liquid is, which is more beneficial for the human body to digest, absorb, and utilize it. The results are shown in Table 5.

[0097] As can be seen from Table 5, the glycosylated modified walnut protein meal replacement shake powder prepared in Example 1 has a solubility of 44.32% after reconstitution. It can dissolve quickly, is easy to prepare, and helps the human body digest and absorb it.

[0098] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a glycosylated modified walnut protein meal replacement shake powder, characterized in that, Includes the following steps: (1) Dissolve walnut meal powder in pure water, add polysaccharide and stir well, then carry out a wet heat glycosylation reaction to obtain a glycosylated modified walnut meal powder solution; (2) The glycosylated modified walnut meal powder solution is mixed evenly with walnut oil, steviol glycosides, xanthan gum and pure water and then emulsified to obtain glycosylated modified walnut protein liquid meal replacement shake; (3) Spray dry the glycosylated modified walnut protein liquid meal replacement shake to obtain a meal replacement shake made of glycosylated modified walnut protein.

2. The preparation method of the glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, In step (1), the ratio of walnut meal powder to pure water is 3g:200mL.

3. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, In step (1), the mass ratio of walnut meal powder to polysaccharide is 5:1; the polysaccharide is selected from natural inulin, β-glucan, and xylooligosaccharide.

4. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, In step (1), the temperature of the wet heat glycosylation reaction is 91°C and the time is 70 min.

5. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, The amounts of each raw material used in step (2) by mass percentage are: 40-80 wt% glycosylated modified walnut meal powder solution, 2.5-12.5 wt% walnut oil, 0.004-0.02 wt% steviol glycosides, 0.05-0.25 wt% xanthan gum, and the remainder is pure water.

6. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 5, characterized in that, The amounts of each raw material in step (2) by mass percentage are: 70-80% glycosylated modified walnut meal powder solution, 4.5-6.5% walnut oil, 0.004-0.008% steviol glycosides, 0.1-0.16% xanthan gum, and the remainder is pure water.

7. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, In step (2), the rotation speed during the emulsification process is 8000 rpm and the emulsification time is 3 min.

8. The method for preparing glycosylated modified walnut protein meal replacement shake powder according to claim 1, characterized in that, In step (3), the parameters for spray drying are: air inlet temperature 185℃ and feed flow rate 25mL / min.

9. A glycosylated modified walnut protein meal replacement shake powder, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. A method for preparing a glycosylated modified walnut protein meal replacement shake powder, characterized in that, Add water to the glycosylated modified walnut protein meal replacement shake powder according to claim 9, and heat and stir. The ratio of the glycosylated modified walnut protein meal replacement shake powder to water is 5g:(15-35)mL; The heating and stirring temperature is 40-80℃, and the time is 30s.

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