Pea protein isolate functionality improving method and pea protein isolate product

Abstract

The invention provides a pea protein isolate functionality improving method and a pea protein isolate product, and relates to the technical field of edible protein processing. The method provided by the invention comprises the following steps: stirring and mixing edible polysaccharide into a pea protein isolate hydrated solution; the functionality comprises at least one of solubility, foamability and emulsibility. According to the invention, the edible polysaccharide is added into the pea protein isolate hydrated solution, and the protein can interact with the polysaccharide to generate a compound or colloid structure, so that the foamability, emulsibility and solubility of the pea protein isolate are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of edible protein processing, and in particular to a method for improving the functionality of pea protein isolate and a pea protein isolate product. Background Art

[0002] In recent years, as people's demand for protein continues to increase and they are more and more concerned about healthy eating, people have begun to consider using plant protein to replace animal protein. Pea protein isolate extracted from peas has attracted much attention due to its high cost-effectiveness, rich in essential amino acids and high digestibility. In addition, pea protein isolate is hypoallergenic and can be suitable for lactose intolerant patients and vegetarians. However, the foaming, emulsification and gel properties of pea protein isolate are inferior to those of animal protein, which greatly limits the application of pea protein isolate in the food industry. Therefore, it is urgent to provide a solution to improve the above problems.

[0003] The purpose of the present invention is to provide a method for improving the functionality of pea protein isolate and a pea protein isolate product. By adding edible polysaccharides into a pea protein isolate hydrate solution, the protein can interact with the polysaccharide to form a complex or a colloidal structure, thereby effectively improving the foaming, emulsification and solubility of the pea protein isolate.

[0004] In a first aspect, the present invention provides a method for improving the functionality of pea protein isolate, comprising: stirring and mixing edible polysaccharides in a pea protein isolate hydration solution; the functionality comprises at least one of solubility, foaming property, and emulsification property.

[0005] The improvement method provided by the present invention is green and environmentally friendly, has low economic cost and is easy to operate, can effectively improve the functionality of pea protein isolate, is suitable for industrial application, and can provide strong support for the large-scale application of pea protein isolate.

[0006] Optionally, the concentration of pea protein isolate in the pea protein isolate hydration solution is 10 g / mL-20 g / mL.

[0007] Optionally, the mass ratio of the edible polysaccharide to the pea protein isolate in the pea protein isolate hydration solution is 1:(10-50).

[0008] Optionally, the edible polysaccharide includes one of gellan gum, carrageenan and konjac gum.

[0009] Optionally, after the edible polysaccharide is stirred and mixed with the pea protein isolate hydration solution, the mass concentration of the edible polysaccharide is 0.001 g / mL-0.01 g / mL.

[0010] Optionally, the edible polysaccharide is stirred and mixed with a 20° C.-30° C. pea protein isolate hydration solution.

[0011] Optionally, the edible polysaccharide is stirred and mixed in the pea protein isolate hydration solution for 1 min-60 min.

[0012] Optionally, the method for preparing the pea protein isolate hydration solution comprises: stirring and mixing the pea protein isolate in ultrapure water, and then hydrating at 4° C. for 10 h to 14 h.

[0013] Optionally, after the edible polysaccharide is stirred and mixed with the pea protein isolate hydration solution, an inorganic edible salt is added and stirred to dissolve.

[0014] Optionally, the inorganic edible salt includes one of sodium chloride, calcium chloride and potassium chloride.

[0015] Optionally, after adding inorganic edible salt and stirring to dissolve, the concentration of the inorganic edible salt is 0.05 mol / L-0.5 mol / L.

[0016] In a second aspect, the present invention also provides a pea protein isolate product obtained by processing with any of the above-mentioned optional enhancement methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a comparison chart of the solubility of pea protein isolate in the pea protein isolate products prepared in Examples 1 to 5 of the present invention and Blank Example 1;

[0018] Figure 2 This is a comparison diagram of the surface hydrophobicity of pea protein isolate in the pea protein isolate products prepared in Examples 1 to 5 of the present invention and Blank Example 1;

[0019] Figure 3 This is a comparison diagram of the foaming states of the pea protein isolate products and gellan gum solutions prepared in Examples 1 to 5 of the present invention and Blank Example 1 at the 0th minute and the 30th minute after homogenization and foaming;

[0020] Figure 4 This is a comparison chart of the foaming properties of the pea protein isolate products prepared in Examples 1 to 5 of the present invention and Blank Example 1;

[0021] Figure 5 This is a comparison chart of foam stability after foaming of the pea protein isolate products prepared in Examples 1 to 5 of the present invention and Blank Example 1;

[0022] Figure 6 This is a comparison chart of the emulsification activity and emulsification stability index of the pea protein isolate products prepared in Examples 1 to 5 of the present invention and Blank Example 1. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0024] The present invention provides a method for improving the functionality of pea protein isolate, comprising: stirring and mixing edible polysaccharides with pea protein isolate hydration solution. The edible polysaccharides and pea protein isolate interact with each other to form a complex or a colloidal structure, thereby effectively improving the functionality of the pea protein isolate. Specifically, the functionality includes one of solubility, foaming property and emulsification property.

[0025] Specifically, the concentration of pea protein isolate in the pea protein isolate hydration solution is 10g / mL-20g / mL. In some embodiments, the preparation method of the pea protein isolate hydration solution includes: stirring and mixing the pea protein isolate in ultrapure water, and hydrating at 4°C for 10h-14h. In fact, the pea protein isolate used can be a commercially available product, or it can be obtained by separating from peas in the laboratory using a conventional method - low temperature and low pressure technology.

[0026] In fact, in the mixture obtained by stirring and mixing the edible polysaccharide with the pea protein isolate hydration solution, the mass ratio of the edible polysaccharide to the pea protein isolate is 1: (10-50). Specifically, by adjusting the amount of the edible polysaccharide and the pea protein isolate, the interaction between the polysaccharide and the pea protein isolate can be optimized. Furthermore, the polysaccharide used includes one of gellan gum, konjac gum, and carrageenan.

[0027] In some embodiments, the edible polysaccharide is stirred and mixed in the mixture obtained by mixing the pea protein isolate hydration solution, and the concentration of the edible polysaccharide is 0.001g / mL-0.01g / mL. In addition, the pea protein isolate hydration solution is placed in an environment of 20°C-30°C in advance, and then the edible polysaccharide is added to the pea protein isolate hydration solution and stirred to dissolve. Specifically, the stirring and dissolving time is controlled to be 1min-60min, which is actually necessary to completely dissolve the edible polysaccharide.

[0028] In some embodiments, after the edible polysaccharide is stirred and mixed with the pea protein isolate hydration solution, the inorganic edible salt is added and stirred to dissolve. In fact, the inorganic edible salt can adjust the protein structure of the pea protein isolate, thereby further improving the functionality of the pea protein isolate. In addition, the combination of edible polysaccharides and inorganic edible salts can comprehensively improve and balance the various functionalities of the pea protein isolate.

[0029] In some embodiments, the inorganic edible salt used includes one of sodium chloride, calcium chloride, and potassium chloride. In fact, after the inorganic edible liquid is added, the concentration of the inorganic edible salt in the mixture is 0.05 mol / L-0.5 mol / L.

[0030] In fact, the present invention also provides a pea protein isolate product obtained by processing with the lifting method in any of the above embodiments.

[0031] Example 1

[0032] This embodiment 1 provides a method for improving the functionality of pea protein isolate, comprising:

[0033] S1. Weigh 16 g of pea protein isolate and add 100 mL of ultrapure water. After magnetic stirring at room temperature of 25° C. for 2 h, hydrate at 4° C. for 12 h to prepare a pea protein isolate hydrate solution.

[0034] S2. 0.4 g of gellan gum was added to the pea protein isolate hydration solution, and the solution was stirred magnetically at room temperature of 25° C. for 30 min to obtain a pea protein isolate product (PPI-GG).

[0035] Example 2

[0036] This embodiment 2 provides a method for improving the functionality of pea protein isolate, which is different from embodiment 1 in that, after magnetic stirring for 30 minutes in step S2, sodium chloride is added and stirred to dissolve and the concentration of sodium chloride is adjusted to 0.05 mol / L to obtain a pea protein isolate product (PPI-GG 0.05 ).

[0037] Example 3

[0038] This embodiment 3 provides a method for improving the functionality of pea protein isolate, which is different from that of embodiment 1 in that, after magnetic stirring for 30 minutes in step S2, sodium chloride is added and stirred to dissolve and the concentration of sodium chloride is adjusted to 0.1 mol / L to obtain a pea protein isolate product (PPI-GG 0.1 ).

[0039] Example 4

[0040] This embodiment 4 provides a method for improving the functionality of pea protein isolate, which is different from that of embodiment 1 in that, after magnetic stirring for 30 minutes in step S2, sodium chloride is added and stirred to dissolve and the concentration of sodium chloride is adjusted to 0.3 mol / L to obtain a pea protein isolate product (PPI-GG 0.3 ).

[0041] Example 5

[0042] This embodiment 5 provides a method for improving the functionality of pea protein isolate, which is different from that of embodiment 1 in that, after magnetic stirring for 30 minutes in step S2, sodium chloride is added and stirred to dissolve and the concentration of sodium chloride is adjusted to 0.5 mol / L to obtain a pea protein isolate product (PPI-GG 0.5 ).

[0043] Blank example 1

[0044] This blank example 1 provides a method for preparing a pea protein isolate product, comprising: weighing 16 g of pea protein isolate, adding 100 mL of ultrapure water, magnetically stirring at room temperature of 25° C. for 2 hours, and hydrating at 4° C. for 12 hours to obtain a pea protein isolate product (PPI).

[0045] Performance Testing

[0046] The products in Examples 1 to 5 and Comparative Example 1 were centrifuged at 12000 rpm for 20 min, and the supernatant was aspirated. The protein concentration in the supernatant was determined using a Bradford protein assay kit, and the ratio of the protein concentration in the supernatant to the concentration of the product before centrifugation was calculated. The results are shown in FIG. Figure 1 shown.

[0047] After 8-aniline-1-naphthalenesulfonic acid was dissolved in a phosphate buffer solution to prepare a 2 mmol / L 8-aniline-1-naphthalenesulfonic acid buffer solution, the products prepared in Examples 1 to 5 were diluted 2, 4, 6, 8, and 10 times with ultrapure water, and then mixed with the 8-aniline-1-naphthalenesulfonic acid buffer solution at a volume ratio of 50:1 and placed in a dark place at room temperature for 15 minutes, and the emission wavelength at 480 nm was measured, the excitation wavelength was set to 390 nm, and the slope of the fluorescence intensity and the concentration of the pea protein isolate was defined as H0. The results are shown in FIG. Figure 2 shown.

[0048] 20 mL of the products in Examples 1 to 5 and Blank Example 1 and a gellan gum aqueous solution with a concentration of 0.004 g / mL were taken in a beaker, and the protein products were homogenized for 60 seconds using a homogenizer at a speed of 10000 rpm, and then quickly transferred to a measuring cylinder, and the total volume at the 0th and 30th minutes was recorded and photographed. The photographed pictures are shown as follows: Figure 3As shown; at the same time, the foaming property and foam stability of the protein product were calculated according to the following formula, and the results are shown Figure 4 and Figure 5 As shown:

[0049]

[0050] Among them, Foam capacity is the foaming property, v0 is the total volume of foam at the 0th minute, and v T is the initial volume of the protein product (20 mL), Foam stability is the foam stability, v 30 It is the total volume of foam at the 30th minute.

[0051] The protein products prepared in Examples 1 to 5 and Blank Example 1 were mixed with 3 mL of corn oil, and then homogenized in a homogenizer at a speed of 12000 rpm for 60 s. 5 μL of the emulsion was immediately drawn from the bottom of the test tube and mixed with 2 mL of a 1 mg / mL SDS solution, and the absorbance A0 was measured at a wavelength of 500 nm. After the homogenized emulsion was allowed to stand for 30 min, 5 μL of the emulsion was drawn from the bottom of the test tube and mixed with 2 mL of a 1 mg / mL SDS solution, and the absorbance A was measured at a wavelength of 500 nm. 30 , and the emulsification activity index (EAI) and emulsion stability index (ESI) were calculated according to the following formula. The results are shown in Figure 6 shown.

[0052]

[0053] Among them, D, C and Φ are the dilution factor, protein product concentration (g / mL) and corn oil volume fraction, respectively.

[0054] from Figure 1 It can be seen that the solubility of the pea protein isolate product prepared in Blank Example 1 is 23.71%, while in Example 1, only gellan gum is added, and the interaction between gellan gum and protein may cause aggregation and precipitation of the pea protein isolate, thereby showing a decrease in the solubility of the pea protein isolate.

[0055] In Example 2 and Example 3, the addition of low concentration of sodium chloride can improve the solubility of pea protein isolate. This is because sodium ions and chloride ions can interact with pea protein isolate, which may lead to the formation of double-layer ionic groups, thereby reducing the electrostatic interaction between pea protein isolates and between pea protein isolates and gellan gum, thereby improving the solubility of pea protein isolate.

[0056] In Examples 4 and 5, the concentration of sodium chloride is too high, which reduces the solubility of the pea protein isolate. This may be because water molecules tend to be more tightly bound to salt ions, resulting in a decrease in the solubility of the pea protein isolate.

[0057] from Figure 2 It can be seen that the addition of gellan gum in Example 1 significantly improves the surface hydrophobicity of the pea protein isolate, which indicates that the interaction between gellan gum and the pea protein isolate can induce the exposure of the hydrophobic sites of the pea protein isolate. At the same time, as sodium chloride is added in Examples 2 to 5 and the concentration of sodium chloride is gradually increased, the unfolding of the pea protein isolate structure and the exposure of the internal hydrophobic residues can be further promoted.

[0058] from Figure 3 and Figure 4 It can be seen that the foaming property of the pure gellan gum aqueous solution can be ignored, and after gellan gum is added in Example 1, the foaming property of the protein product is reduced by 36.07%. As sodium chloride is added in Examples 2 to 5 and the sodium chloride solubility gradually increases, the foaming property of the protein product tends to increase first and then decrease, and the foaming property reaches the maximum when the sodium chloride concentration is 0.05 mol / L, which is similar to the trend of the solubility of pea protein isolate, indicating that protein solubility is the main factor affecting the foaming property. This may be because the reduction in the soluble protein content weakens the adsorption of protein at the air-water interface, thereby having a negative impact on the formation of foam.

[0059] from Figure 3 and Figure 5 It can be seen that although the content of soluble pea protein isolate is reduced, the addition of gellan gum in Example 1 does not significantly affect the stability of the foam after foaming. This may be because the hydrophilic polysaccharide chains in the gellan gum protrude into the water phase, increasing the local viscosity around the foam and reducing the foam drainage rate. In addition, the steric hindrance between the protein-polysaccharide complex can inhibit the foaming aggregation.

[0060] In Examples 2 to 5, the foam stability of the protein products after foaming increases with the increase of sodium chloride concentration, and the stability is highest when the sodium chloride concentration is 0.1 mol / L. However, the stability decreases with the continuous increase of sodium chloride concentration. This shows that an appropriate concentration of sodium chloride can promote the dissolution of pea protein isolate and expose hydrophobic groups to promote the formation of a stable interfacial film. In addition, a high concentration of sodium chloride will lead to strong electrostatic shielding, reduce the affinity of protein for water molecules, and thus weaken the foaming property and foam stability of the protein.

[0061] from Figure 6It can be seen that the addition of gellan gum and sodium chloride to pea protein isolate can improve the emulsification activity and emulsification stability of pea protein isolate. After adding gellan gum in Example 1, more hydrophobic groups are exposed on the surface of pea protein isolate, thereby strengthening the contact between pea protein isolate and oil phase, thereby increasing the emulsification activity by 25.08%. At the same time, the pea protein isolate-gellan gum complex adsorbed on the interface can produce steric hindrance between droplets, thereby helping to stabilize the emulsion. At the same time, after adding sodium chloride in Examples 2 to 5, an appropriate concentration of sodium chloride can increase the solubility of pea protein isolate, thereby comprehensively improving the emulsification activity and emulsification stability. However, the electrostatic shielding generated by high concentrations of sodium chloride will have a negative impact on the stability of the emulsion.

[0062] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A method for improving the functionality of pea protein isolate, characterized in that: include: The edible polysaccharide is stirred and mixed in the pea protein isolate hydration solution; the functionality includes at least one of solubility, foaming property and emulsification property.

2. The lifting method according to claim 1, characterized in that: The concentration of pea protein isolate in the pea protein isolate hydration solution is 10 g / mL-20 g / mL; and / or the mass ratio of the edible polysaccharide to the pea protein isolate in the pea protein isolate hydration solution is 1:(10-50).

3. The lifting method according to claim 1, characterized in that: The edible polysaccharide comprises one of gellan gum, carrageenan and konjac gum; and / or, after the edible polysaccharide is stirred and mixed with the pea protein isolate hydration solution, the concentration of the edible polysaccharide is 0.001 g / mL-0.01 g / mL.

4. The lifting method according to claim 1, characterized in that: The edible polysaccharide is stirred and mixed in a 20° C.-30° C. pea protein isolate hydration solution; and / or, the edible polysaccharide is stirred and mixed in the pea protein isolate hydration solution for 1 min-60 min.

5. The lifting method according to claim 1, characterized in that: The preparation method of the pea protein isolate hydration solution comprises: stirring and mixing the pea protein isolate in ultrapure water, and then hydrating at 4° C. for 10 hours to 14 hours.

6. The lifting method according to any one of claims 1 to 5, characterized in that: After the edible polysaccharide is stirred and mixed with the pea protein isolate hydration solution, the inorganic edible salt is added and stirred to dissolve.

7. The lifting method according to claim 6, characterized in that: The inorganic edible salt includes one of sodium chloride, calcium chloride and potassium chloride; and / or, after the inorganic edible salt is added, stirred and dissolved, the concentration of the inorganic edible salt is 0.05 mol / L-0.5 mol / L.

8. A pea protein isolate product obtained by the upgrading method according to any one of claims 1 to 7.

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