Meal replacements based on carrageenan and soy protein isolate, and methods for producing the same.

Abstract

This invention discloses a meal replacement based on carrageenan and soy protein isolate, and a method for producing the same. The meal replacement includes a SPI / λC / ιC mixed solution beverage containing, by mass fraction, 5% soy protein isolate, 0.25% to 0.75% λ-carrageenan, and 0.25% to 1% ι-carrageenan, and a SPI / λC / ιC gel formed by induction from the SPI / λC / ιC mixed solution under acidic conditions. The SPI / λC / ιC mixed solution beverage produced by this invention forms a hydrogel after consumption due to the action of stomach acid, exhibiting relatively high gel strength. This extends the evacuation time of the hydrogel in the stomach, increasing the consumer's feeling of fullness and reducing calorie intake, thereby potentially reducing body weight.

Description

Technical Field

[0001] The present invention belongs to the field of food processing technology, and specifically relates to a meal substitute based on carrageenan and soy protein isolate and a method for producing the same.

Background Art

[0002] Overweight and obesity may cause cardiovascular diseases. Similarly, the weight of obese people places a great burden on the body and may cause joint pain, movement disorders, etc. Furthermore, overweight and obesity are also causes of diseases such as sleep apnea syndrome, endocrine and metabolic disorders, gallbladder diseases, and fatty liver.

[0003] A mixture of protein and a biopolymer with a relatively high electro negativity forms a gastric gel at a relatively low polysaccharide concentration, generates a feeling of fullness, reduces food intake, delays the digestion rate of food, and can effectively support weight management. Soy protein isolate (SPI) is a protein powder with excellent nutritional value and functional properties, which is produced by using low-temperature defatted soybean meal as a raw material and removing non-protein components through processes such as extraction and separation. It gives the strongest feeling of fullness among all macronutrients and can be applied to weight management and obesity suppression. Carrageenan, also known as kappacarrageenan, chondrus gum, chondrus crispus gum, is a calcium salt, potassium salt, sodium salt, ammonium salt of a polysaccharide sulfate ester composed of galactose and dehydrated galactose, and is widely used as a gelling agent in foods. Carrageenan itself has a satiety effect as a dietary fiber, gives a feeling of fullness and does not supply extra energy to the human body. When complexed with soy protein isolate, it forms a gel under conditions much lower than the isoelectric point pH of the protein and can be used as a diet meal substitute. However, a simple soy protein isolate / carrageenan gel has drawbacks such as low mechanical strength, fast decomposition rate, poor water retention ability, and short satiety duration.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In response to the shortcomings of conventional technology, the object of the present invention is to provide a diet meal substitute composed of carrageenan and soybean isolated protein that has high strength, strong water retention capacity, and a long-lasting satiety period, as well as a method for producing the same. [Means for solving the problem]

[0005] To achieve the above objective, the present invention employs the following technical solutions.

[0006] In a first embodiment, the present invention provides a meal replacement beverage based on carrageenan and soy protein isolate, in terms of mass fraction, Contains 5% soybean protein isolate, 0.25% to 0.75% λ-carrageenan, 0.25% to 1% ι-carrageenan, and the remainder is water.

[0007] In a second embodiment, the present invention provides a method for producing a meal replacement beverage as provided in the first embodiment. The process includes the step of adding soybean protein isolate, λ-carrageenan, and ι-carrageenan to pure water, heating and stirring to dissolve them, and then cooling.

[0008] In a third embodiment, the present invention provides a meal replacement gel based on carrageenan and soy protein isolate, which is formed by induction under acidic conditions from aqueous solutions of soy protein isolate, λ-carrageenan, and ι-carrageenan.

[0009] In a fourth embodiment, the present invention provides a method for producing a meal replacement gel as provided in the third embodiment. The steps include adding soybean protein isolate, λ-carrageenan, and ι-carrageenan to pure water, heating and stirring to dissolve them, and obtaining a mixed solution, The procedure includes the steps of cooling the mixed solution to room temperature, placing it in a dialysis bag, and immersing it in an acidic solution to obtain the gel. [Effects of the Invention]

[0010] Compared to the prior art, the beneficial effects of the present invention are as follows: (1) The present invention provides a method for producing a meal replacement by forming a hydrogel by acid induction using soybean isolated protein, λ-carrageenan, and ι-carrageenan. Electrostatic interactions occur between the protein and anionic polysaccharides, forming a gel with a network structure. λ-carrageenan and ι-carrageenan have relatively high electronegativity, and their synergistic effect reinforces the stability of the network structure, improving gel strength and water retention capacity, extending the expulsion time of the hydrogel in the stomach, and effectively extending satiety duration. (2) The hydrogel produced by the present invention has good biocompatibility and safety, meeting food-grade requirements. The complex solution of soybean isolated protein and λ-carrageenan and ι-carrageenan enters the stomach and rapidly forms a gel, creating a gel film on the surface. After the gel, most of the protein is enclosed within the gel, and digestion in the stomach proceeds gradually from the outside of the gel, providing only a feeling of fullness. The abundant soybean isolated protein can provide a relatively good source of nutrients, and by reducing calorie intake, it can reduce weight without adverse effects on the human body. (3) The manufacturing method of the present invention has a simple process and is convenient for industrial mass production. [Brief explanation of the drawing]

[0011] [Figure 1] This is a laser confocal microscope image of the hydrogel prepared in Example 1. [Figure 2] This is a low-field nuclear magnetic resonance spectrum diagram of the hydrogel produced in Example 1. [Modes for carrying out the invention]

[0012] The present invention will be described in more detail below with reference to specific examples, in order to enable those skilled in the art to understand the present invention more clearly. The examples provided are used to illustrate the present invention and do not limit the scope of the present invention. In the examples of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art, and unless otherwise specified, the technical means used are common means well known to those skilled in the art.

[0013] The meal replacement beverages based on carrageenan and soy protein isolate provided in the embodiments of the present invention are, by mass fraction, Contains 5% soybean protein isolate, 0.25% to 0.75% λ-carrageenan, 0.25% to 1% ι-carrageenan, and the remainder is water.

[0014] When the meal replacement beverage enters the stomach, the induction of stomach acid allows the protein and carrageenan to rapidly form a gel with a network structure through electrostatic interactions. λ-carrageenan and ι-carrageenan have relatively high electronegativity, and their synergistic effect can further stabilize the network structure, resulting in a gel with high strength and strong water retention capacity.

[0015] The method for producing a meal replacement beverage based on carrageenan and soybean protein isolate provided in the examples of the present invention is: The process includes the step of adding soybean protein isolate, λ-carrageenan, and ι-carrageenan to pure water, heating and stirring to dissolve them, and then cooling.

[0016] In some preferred embodiments, the heating temperature is 90-98°C.

[0017] The meal replacement gels based on carrageenan and soy protein isolate provided in the embodiments of the present invention are formed by induction under acidic conditions from aqueous solutions of soy protein isolate, λ-carrageenan, and ι-carrageenan.

[0018] In some preferred embodiments, the raw material composition of the meal replacement gel is, in terms of mass fraction, It contains 5% soy protein isolate, 0.25% - 0.75% lambda-carrageenan, 0.25% - 1% iota-carrageenan, and the balance water.

[0019] In some preferred embodiments, the pH under acidic conditions is 1 - 2.

[0020] The method for manufacturing a meal replacement gel based on carrageenan and soy protein isolate provided in the examples of the present invention is as follows: Adding soy protein isolate, lambda-carrageenan, and iota-carrageenan to pure water, heating and stirring to dissolve to obtain a mixed solution; After cooling the mixed solution to room temperature, putting it into a dialysis bag and immersing it in an acidic solution to obtain the gel.

[0021] In some preferred embodiments, the acidic solution is a hydrochloric acid solution.

[0022] In some preferred embodiments, the pH of the acidic solution is 1 - 2.

[0023] (Comparative Example 1) This comparative example provides 5 groups of meal replacement gels composed of soy protein isolate and different contents of lambda-carrageenan, and the manufacturing method is as follows. Adding lambda-carrageenan and SPI powder to a flask containing a certain amount of ultrapure water, then stirring at 95 °C and 750 rpm for 1.5 h to obtain a SPΙ / λC mixed solution. After cooling to room temperature, putting it into a dialysis bag and immersing it in a hydrochloric acid solution with a pH of 1.2 for 24 h to form a SPΙ / λC gel.

[0024] Taking out and cutting the SPΙ / λC gels of each group for performance testing. The composition of the blending raw materials and the performance test results of each group are shown in Table 1.

[0025]

Table 1

[0026] The maximum hardness of the hydrogel obtained in this comparative example was 0.5 N for group D3. This is because λ-carrageenan has a high charge density, and although the electrostatic interaction force becomes stronger at relatively high concentrations, the relatively high gel rate and system viscosity during the gelling process cause hollow structures to form in the gel, affecting the properties of the gel and reducing its hardness.

[0027] (Example 1) This embodiment provides seven groups of meal replacement gels composed of soybean protein isolate, λ-carrageenan, and ι-carrageenan in different amounts, and the manufacturing method is as follows. SPI powder, λ-carrageenan, and ι-carrageenan were added to a flask containing a certain amount of ultrapure water, and then stirred at 750 rpm at 95°C for 1.5 hours to obtain a mixed SPI / λC / ιC solution. After cooling to room temperature, the solution was placed in a dialysis bag and immersed in a pH 1.2 hydrochloric acid solution for 24 hours to form an SPI / λC / ιC gel.

[0028] The SPI / λC / ιC gels from each group were extracted, cut, and subjected to performance testing. The raw material composition and performance test results for each group are shown in Table 2.

[0029] [Table 2]

[0030] Figure 1 shows micrographs of acid-induced SPI / λC / ιC gels at different ι-carrageenan concentrations, taken using a laser confocal microscope. In the figure, the bright red areas represent the protein network stained with rhodamine B, and the black areas represent the protein-deficient serum phase. As the ι-carrageenan content increases (>0.25%, w / w), the stiffness of the SPI / λC / ιC gel increases, and the gel structure improves. At an ι-carrageenan content of 0.55%, the network structure was observed to be the most uniform and dense, and the gel stiffness was at its maximum at this point. As the ι-carrageenan content continues to increase, the gel stiffness decreases. As can be seen from the laser confocal microscope images, a structure similar to phase separation appears, and the concentration of polysaccharides determines the degree of phase separation and whether proteins and polysaccharides form a continuous network. At relatively low concentrations of ι-carrageenan, the interaction between λ-carrageenan and proteins takes center stage. In this case, protein particles and λ-carrageenan form a gel backbone through electrostatic interaction, creating a continuous phase. When the ι-carrageenan concentration is 0.55% (w / w), the two different types of carrageenan form a double continuous gel network structure, and this gel network structure is the most stable. As the ι-carrageenan concentration is continuously increased, ι-carrageenan takes center stage, the continuity of the protein phase is lost, and the gel network transforms into a continuous phase structure mainly composed of ι-carrageenan. In this type of network, SPIs are embedded in the carrageenan continuous phase in the form of irregular aggregates. Blending the two types of carrageenan effectively prevents aggregation by reinforcing electrostatic repulsion and reducing hydrophobic interactions. The combination of carrageenans contributes to the formation and development of a crosslinking network through intermolecular association between polysaccharide chains, thereby inhibiting crosslinking aggregation due to strong electrostatic interactions between carrageenan and protein micelles.

[0031] By using low-frequency nuclear magnetic resonance (LF-NMR) techniques to measure T2 relaxation times, we study the proportion and distribution of water in different states in acid-induced SPI / λC / ιC gel systems. Generally, fitting and inverse transforming LF-NMR spectra generates three distinct T2 distribution peaks, corresponding to three different water states: strongly bound water (1–10 ms, P21), weakly bound water (10–600 ms, P22), and free water (>600 ms, P23). The LF-NMR spectra of acid-induced SPI / λC / ιC gels are shown in Figure 2. As can be seen, weakly bound water (>97%) occupies a dominant position in acid-induced SPI / λC / ιC gels. With increasing ι-carrageenan content, weakly bound water gradually increases, while strongly bound water and free water slightly decrease. The results showed that with the addition of ι-carrageenan (0.25%), the gel developed a relatively broad shoulder on the P22 peak (10-600 ms), indicating an increase in the degrees of freedom of water molecules. As ι-carrageenan continued to increase, the shoulder gradually narrowed, indicating a stronger interaction between the gel and water, which may be due to the hydrophilicity of carrageenan.

[0032] In summary, this embodiment increases the crosslinking density and structural rigidity through the synergistic effect of λ-carrageenan and ι-carrageenan, improving the hardness of the hydrogel, extending digestion time, and enhancing the feeling of fullness.

[0033] (Example 2) This embodiment provides three groups of meal replacement gels composed of soybean isolated protein and λ-carrageenan and ι-carrageenan in different amounts, and the manufacturing method is as follows. SPI powder, λ-carrageenan, and ι-carrageenan were added to a flask containing a certain amount of ultrapure water, and then stirred at 750 rpm at 95°C for 1.5 hours to obtain a mixed SPI / λC / ιC solution. After cooling to room temperature, the solution was placed in a dialysis bag and immersed in a pH 2 hydrochloric acid solution for 24 hours to form an SPI / λC / ιC gel.

[0034] The SPI / λC / ιC gels from each group were extracted, cut, and subjected to performance testing. The raw material composition and performance test results for each group are shown in Table 3.

[0035] [Table 3]

[0036] (Comparative Example 2) In this comparative example, ι-carrageenan was replaced with κ-carrageenan, and a gel composed of soybean protein isolate, λ-carrageenan, and κ-carrageenan in different amounts was prepared. The preparation method is as follows. SPI powder, λ-carrageenan, and κ-carrageenan were added to a flask containing a certain amount of ultrapure water, and then stirred at 750 rpm at 95°C for 1.5 hours to obtain a mixed solution of SPI / λC / κC. Upon cooling, a gel was formed.

[0037] The SPI / λC / κC gels from each group were extracted, cut, and subjected to performance testing. The raw material composition and performance test results for each group are shown in Table 4.

[0038] [Table 4]

[0039] This comparative example can form a gel without requiring acid induction, but it is relatively hard, difficult to swallow, and has an inferior texture.

[0040] The foregoing are merely preferred embodiments of the present invention and do not limit it. All modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should all be included within the scope of protection of the present invention.

Claims

1. A meal replacement gel based on carrageenan and soy protein isolate, which is formed by induction under acidic conditions from an aqueous solution of soy protein isolate, λ-carrageenan, and ι-carrageenan. The raw material composition of the aforementioned meal replacement gel is, in terms of mass fraction, Contains 5% soybean protein isolate, 0.25% to 0.75% λ-carrageenan, 0.25% to 1% ι-carrageenan, and the remainder being water. A meal replacement gel based on carrageenan and soybean isolated protein, characterized in that the pH of the aforementioned acidic conditions is 1 to 2.

2. The steps include adding soybean protein isolate, λ-carrageenan, and ι-carrageenan to pure water, heating and stirring to dissolve them, and obtaining a mixed solution, A method for producing a meal replacement gel based on carrageenan and soybean isolated protein according to claim 1, comprising the steps of: cooling the mixed solution to room temperature, placing it in a dialysis bag, and immersing it in an acidic solution to obtain the gel.

3. The method for producing a meal replacement gel based on carrageenan and soybean isolated protein according to claim 2, characterized in that the acidic solution is a hydrochloric acid solution.

4. The method for producing a meal replacement gel based on carrageenan and soybean protein isolate according to claim 2, characterized in that the pH of the acidic solution is 1 to 2.

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