Method for preparing ice cream by using soybean protein amyloid fiber

Abstract

The invention discloses a method for preparing ice cream by using soybean protein amyloid fiber, and belongs to a soybean byproduct utilization technology. The method comprises the following steps: (1) preparing the soybean protein amyloid fiber; (2) compounding ice cream; (3) preparing an ice cream emulsion; and (4) hardening and forming. According to the method, the characteristic that the soybean protein amyloid fiber can better inhibit ice crystallization is applied, the melting rate of ice cream is reduced to 26.38 + / -0.12 from the original 37.17 + / -0.03, and the SAFs content reaches 4.00 + / -0.34%. An experiment for inhibiting ice crystallization by amyloid fibers proves that SAFs prove the ice crystallization activity in the low-calorie ice cream stored at-18 DEG C for 7 days. The APFs are adsorbed on an air-water and fat-water interface, and the APFs have significant influence on the melting rate, appearance and color, particle size distribution, hardness, rheological properties and smell flavor of the ice cream. The research proves that SAFs is a cheap food-grade ice crystal active substance and has great potential in frozen desserts such as ice cream.

Description

Technical Field

[0001] The present invention belongs to the technology of utilizing acid-treated soybean by-products, and mainly relates to a method for making ice cream using soy protein amyloid fibrils. Background Art

[0002] As a widely popular frozen dessert, the market demand for ice cream continues to grow. However, traditional ice cream relies on a high fat content (usually 15%) and a large amount of added sugar to achieve the desired taste and texture, which brings health risks such as obesity, cardiovascular diseases, and diabetes. In addition, traditional emulsifiers and stabilizers (such as guar gum, carrageenan, etc.) are mostly synthetic or extracted components, and their sustainability and clean label attributes are questioned by consumers. With the improvement of health awareness, the market's demand for low-fat, low-sugar, high-protein, and clean label ice cream is becoming increasingly urgent. However, reducing fat and sugar will lead to problems such as rough texture, large ice crystals, and poor taste of ice cream. There is an urgent need for a new type of material to replace or reduce the content of fat and stabilizers in ice cream.

[0003] Soy protein amyloid fibrils (SAFs) are rigid, linear supramolecular structures formed by the partial hydrolysis and self-assembly of soy proteins (such as β-conglycinin, glycinin) under specific conditions (such as low pH, high temperature, long-term heating, or enzymatic treatment). Its core characteristics include (1) β-sheet stacking structure: a parallel / antiparallel β-sheet structure formed by misfolding of protein molecules, stabilized by hydrogen bonds (fiber diameter is about 5-15 nm, and the length can reach several micrometers). (2) High aspect ratio (>100:1), endowing it with excellent interfacial activity and gel-forming ability. (3) Rich in hydrophobic cores and hydrophilic surface residues, making it have both emulsifying and hydration abilities.

[0004] SAFs significantly improve the stability, texture, and sensory properties of ice cream emulsion systems through multiple physicochemical interactions. The hydrophobic core (β-sheet structure) of SAFs binds to the hydrophobic region of fat droplets, and the hydrophilic ends (exposed polar amino acids) extend into the aqueous phase. A surfactant adsorption is formed (the particle size distribution is reduced by 20%-30%), thereby stabilizing the ice cream emulsion interface. The high water-holding capacity of SAFs (up to 10 g water / g protein) slows down the loss of the liquid phase after melting, maintains shape stability, and the anti-solubility can be increased by more than 10%. The fiber network divides the aqueous phase into micro-regions, restricting the diffusion and growth of ice crystals. Optical microscopy shows that the average size of ice crystals is reduced by 20%-30%. The abundant hydroxyl / carboxyl groups of SAFs lock free water through hydrogen bonds. Through nuclear magnetic imaging, it is found that the free water activity (Aw) becomes dispersed, delaying the ice crystal nucleation rate. This indicates that ice crystal growth can be inhibited by water molecule binding. SAFs co-adsorb with milk proteins (such as casein), reducing the interfacial tension and increasing the overrun (the overrun increases by 15%-20%). Some studies have found that compared with hydrolyzed soy protein, SAFs retain intact essential amino acids (the lysine loss rate decreases from 12% to 3%).

[0005] The present invention first proposes and adopts a method for preparing ice cream by adding SAFs, which can achieve the purpose of green, safe, and high-value utilization of soybean by-products. The unique biological activity of SAFs itself endows the ice cream with a good taste. The melting experiment proves the potential function of SAFs in ice cream. Therefore, the functional protein complex prepared by this method can be widely applied to other functional foods, and the present invention has application value and strong practicability in frozen desserts such as ice cream bars and yogurt. Summary of the Invention

[0006] The present invention provides a method for making ice cream using a kind of soy protein amyloid fiber. The operation process of this method is simple, and the protein product has a high cost performance, achieving the purpose of the fat content of ice cream, improving anti-solubility, and keeping the taste unchanged.

[0007] The technical problems to be solved by the present invention are realized through the following technical solutions:

[0008] A method for making ice cream using soy protein amyloid fibers, characterized in that the method comprises the following steps: (1) Preparation of soy protein amyloid fibers: Adjust the material-liquid ratio, pH, and heat of commercially available soy protein powder, spray dry, collect the dry powder, and store it in a drying dish; (2) Ice cream compounding: At 50-60 °C, soy protein amyloid fibers, milk powder, sucrose, cream, xanthan gum, and maltodextrin are compounded in a ratio of 4:15(11):11:3:0.5:0.5 (w:w); (3) Preparation of ice cream emulsion: After the ice cream raw materials are formulated according to step (2), they are sterilized, homogenized, cooled, and frozen in sequence; (4) Hardening and forming: The hardening condition is -25 °C and the hardening time is 24 h.

[0009] The method for making ice cream using soy protein amyloid fibers as described above, characterized in that the preparation process of the soy protein amyloid fibers is as follows: Adjust the material-liquid of commercially available soy protein powder according to the following conditions: The material-liquid ratio is 3:97, pH is 2.0, the temperature is 85 °C, and the oil bath times are 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220 °C, an outlet temperature of 200 °C, and a peristaltic speed of 5 mL / min. Collect the dry powder and store it at room temperature for standby.

[0010] The method for making ice cream emulsion using soy protein amyloid fibers as described above, characterized in that the preparation conditions of the ice cream emulsion are as follows: Sterilization: Carry out at 85 °C for 20 min, Homogenization: The rotation speed is 10,000 rpm and the time is 2 min, Cooling: The cooling temperature is 4 °C and the cooling time is 4-24 h, Freezing: Stir vigorously at -4 °C.

[0011] The method for making ice cream emulsion using soy protein amyloid fibers as described above, characterized in that the xanthan gum (XG) and maltodextrin (MD) are both food grade.

[0012] This method applies the better ice crystal inhibition property of soy protein amyloid fibers, reducing the melting rate of ice cream from the original 37.17±0.03 to 26.38±0.12, and the content of SAFs reaches 4.00±0.34%. The ice crystal inhibition experiment of amyloid fibers confirms that SAFs prove the ice crystal activity in low-calorie ice cream stored at -18 °C for 7 days. APFs adsorb on the air-water and fat-water interfaces, and APFs have a significant impact on the melting rate, appearance and color, particle size distribution, hardness, rheological properties, and olfactory flavor of ice cream. Research proves that SAFs are a kind of cheap food-grade ice crystal active substances and have great potential in frozen desserts such as ice cream. Description of the Drawings

[0013] Figure 1 It is the overall process route diagram of the present invention.

[0014] Figure 2 Effect of adding

[0014] Figure 2 to the particle size of ice cream emulsion in Example 1

[0015] Figure 3 Effect of adding

[0014] Figure 2 to the viscosity of ice cream emulsion in Example 2

[0016] Figure 4 Effect of adding

[0014] Figure 2 to the water distribution in ice cream emulsion in Example 3

[0017] Figure 5 Effect of adding

[0014] Figure 2 to the microstructure of ice cream emulsion in Example 4

[0018] Figure 6 Effect of adding

[0014] Figure 2 to the melting speed of ice cream in Example 5

[0019] Figure 7 Effect of adding

[0014] Figure 2 to the melting rate of ice cream in Example 5 Detailed implementation manners

[0020] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] A method for making ice cream using soy protein amyloid fibers, characterized in that the method comprises the following steps: (1) Preparation of soy protein amyloid fibers: Adjust the solid-liquid ratio, pH, and heating of commercially available soy protein powder, spray dry, collect the dry powder, and store it in a drying dish; (2) Ice cream compounding: At 50 - 60 °C, soy protein amyloid fibers, milk powder, sucrose, cream, xanthan gum, and maltodextrin are compounded in a ratio of 4:15(11):11:3:0.5:0.5 (w:w); (3) Preparation of ice cream emulsion: After the ice cream raw materials are formulated in step (2), they are sterilized, homogenized, cooled, and frozen in sequence; (4) Hardening and forming: The hardening condition is -25 °C and the hardening time is 24 h.

[0022] The method for making ice cream using soy protein amyloid fibers as described above, characterized in that the preparation process of the soy protein amyloid fibers is as follows: Adjust the solid-liquid ratio of commercially available soy protein powder according to the following conditions: solid-liquid ratio 3:97, pH 2.0, temperature 85 °C, and the oil bath times are 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220 °C, an outlet temperature of 200 °C, and a peristaltic speed of 5 mL / min. Collect the dry powder and store it at room temperature for standby.

[0023] A method for making ice cream emulsion using soy protein amyloid fibers, characterized in that the preparation conditions of the ice cream emulsion are: sterilization: at 85°C for 20 minutes, homogenization: rotation speed of 10,000 rpm, time of 2 minutes, cooling: cooling temperature of 4°C, cooling time of 4 - 24 hours, freezing: vigorous stirring at -4°C.

[0024] A method for making ice cream emulsion using soy protein amyloid fibers, characterized in that the xanthan gum (XG) and maltodextrin (MD) are both food grade.

[0025] Example 1:

[0026] The preparation process of the soy protein amyloid fibers is as follows: The commercially available soy protein powder is adjusted according to the following conditions: solid-liquid ratio of 3:97, pH of 2.0, temperature of 85°C, and oil bath times of 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220°C, an outlet temperature of 200°C, and a peristaltic speed of 5 mL / min. The dried powder is collected and stored at room temperature for later use; ice cream compounding: Under the condition of 50 - 60°C, milk powder, sucrose, cream, xanthan gum, and maltodextrin are compounded in a ratio of 15:11:3:0.5:0.5 (w:w). After the ice cream raw materials are formulated according to step (2), they are sequentially sterilized, homogenized, cooled, and frozen; hardening and forming: The hardening condition is -25°C and the hardening time is 24 h. The results of the effect of SAFs addition on the particle size of the ice cream emulsion are shown in Figure 2 .

[0027] Example 2:

[0028] The preparation process of the soy protein amyloid fibers is as follows: The commercially available soy protein powder is adjusted according to the following conditions: solid-liquid ratio of 3:97, pH of 2.0, temperature of 85°C, and oil bath times of 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220°C, an outlet temperature of 200°C, and a peristaltic speed of 5 mL / min. The dried powder is collected and stored at room temperature for later use; ice cream compounding: Under the condition of 50 - 60°C, soy protein, milk powder, sucrose, cream, xanthan gum, and maltodextrin are compounded in a ratio of 4:15:11:3:0.5:0.5 (w:w). After the ice cream raw materials are formulated according to step (2), they are sequentially sterilized, homogenized, cooled, and frozen; hardening and forming: The hardening condition is -25°C and the hardening time is 24 h. The results of the effect of SAFs addition on the viscosity of the ice cream emulsion are shown in Figure 3 .

[0029] Example 3:

[0030] The preparation process of the soy protein amyloid fiber is as follows: Adjust the material-liquid ratio of commercially available soy protein powder under the following conditions: the material-liquid ratio is 3:97, pH is 2.0, the temperature is 85 °C, and the oil bath times are 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220 °C, an outlet temperature of 200 °C, a peristaltic speed of 5 mL / min. Collect the dried powder and store it at room temperature for later use; Ice cream compounding: Under the condition of 50-60 °C, compound 3 h soy protein amyloid fiber, milk powder, sucrose, cream, xanthan gum, and maltodextrin in a ratio of 4:15:11:3:0.5:0.5 (w:w). After the ice cream raw materials are formulated according to step (2), they are sterilized, homogenized, cooled, and frozen in sequence; Hardening and forming: The hardening condition is -25 °C and the hardening time is 24 h. The results of the effect of SAFs addition on the water distribution of the ice cream emulsion are shown in Figure 4 。

[0031] Example 4:

[0032] The preparation process of the soy protein amyloid fiber is as follows: Adjust the material-liquid ratio of commercially available soy protein powder under the following conditions: the material-liquid ratio is 3:97, pH is 2.0, the temperature is 85 °C, and the oil bath times are 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220 °C, an outlet temperature of 200 °C, a peristaltic speed of 5 mL / min. Collect the dried powder and store it at room temperature for later use; Ice cream compounding: Under the condition of 50-60 °C, compound 6 h soy protein amyloid fiber, milk powder, sucrose, cream, xanthan gum, and maltodextrin in a ratio of 4:15:11:3:0.5:0.5 (w:w). After the ice cream raw materials are formulated according to step (2), they are sterilized, homogenized, cooled, and frozen in sequence; Hardening and forming: The hardening condition is -25 °C and the hardening time is 24 h. The results of the effect of SAFs addition on the microstructure of the ice cream emulsion are shown in Figure 5 。

[0033] Example 5:

[0034] The preparation process of the soy protein amyloid fiber is as follows: Adjust the material-liquid ratio of commercially available soy protein powder under the following conditions: the material-liquid ratio is 3:97, pH is 2.0, the temperature is 85 °C, and the oil bath times are 0 h, 3 h, 6 h, and 12 h respectively. The conditions for spray drying are an inlet temperature of 220 °C, an outlet temperature of 200 °C, a peristaltic speed of 5 mL / min. Collect the dried powder and store it at room temperature for later use; Ice cream compounding: Under the condition of 50-60 °C, compound 12 h soy protein amyloid fiber, milk powder, sucrose, cream, xanthan gum, and maltodextrin in a ratio of 4:15:11:3:0.5:0.5 (w:w). After the ice cream raw materials are formulated according to step (2), they are sterilized, homogenized, cooled, and frozen in sequence; Hardening and forming: The hardening condition is -25 °C and the hardening time is 24 h. The results of the effect of SAFs addition on the melting speed of the ice cream are shown inFigure 6 and Figure 7 。

Claims

1. A method for making ice cream using soybean protein amyloid fibers, characterized in that: The method comprises the following steps: (1) preparing soybean protein amyloid fibers: adjusting the material-liquid ratio and pH value of commercially available soybean protein powder, heating, spray drying, collecting the dried powder, and storing it in a drying dish; (2) compounding ice cream: under the condition of 50-60° C., compounding soybean protein amyloid fibers, milk powder, sucrose, cream, xanthan gum, and maltodextrin in a ratio of 4:15 (11):11:3:0.5:0.5 (w:w); (3) preparing ice cream emulsion: after the ice cream raw materials are prepared according to step (2), sterilization, homogenization, cooling, and freezing are carried out in sequence; (4) hardening and molding: the hardening condition is -25° C., and the hardening time is 24 hours.

2. The method for making ice cream using soybean protein amyloid fibers according to claim 1, characterized in that: The preparation process of the soy protein amyloid fiber is as follows: the commercially available soy protein powder is adjusted to the liquid according to the following conditions: liquid-to-solid ratio 3:97, pH 2.0, temperature 85°C, oil bath time 0h, 3h, 6h, 12h respectively. The spray drying conditions are inlet temperature 220°C, outlet temperature 200°C, peristaltic speed 5mL / min, and the dry powder is collected and stored at room temperature for later use.

3. The method for preparing ice cream emulsion using soybean protein amyloid fibers according to claim 1, characterized in that: The preparation conditions of the ice cream emulsion are as follows: sterilization: 85°C for 20 min, homogenization: rotation speed 10000 rpm, time 2 min, cooling: cooling temperature 4°C, cooling time 4-24h, freezing: -4°C with vigorous stirring.

4. The method for preparing ice cream emulsion using soybean protein amyloid fibers according to claim 1, characterized in that: The xanthan gum (XG) and maltodextrin (MD) are both food grade.

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