A method for improving the emulsification performance of a zein graft

Abstract

The application discloses a method for improving emulsifying performance of a zein graft, and the method comprises the following steps: adding anti-dextran monoclonal antibody D24 in a process of preparing a zein-dextran graft emulsion, and improving the emulsifying performance of the zein-dextran graft emulsion.

Description

Technical fields:

[0001] This invention relates to the field of protein processing, specifically to a method for improving the emulsifying properties of zein grafts. Background technology:

[0002] Zealysin is the main protein component of cornmeal, a byproduct of corn processing. It is typically extracted using solvent extraction and is classified as an alcohol-soluble glutenin. The U.S. Food and Drug Administration (FDA) considers zealysin a safe and valuable food ingredient, possessing advantages such as being non-toxic, biodegradable, environmentally friendly, and edible. Non-polar amino acid residues comprise more than half of the total amino acid content in zealysin molecules. Its strong hydrophobicity makes it insoluble in water but soluble in ethanol, limiting its applications.

[0003] In recent years, protein grafting modification has attracted widespread attention from scholars both domestically and internationally as a green, safe, and pollution-free modification method. Protein grafting modification occurs between the reduced carbonyl group of a sugar molecule and the ε-amino group of the protein. Based on the Maillard reaction, condensation and rearrangement form glycosylamine rearrangement products, namely protein-glycan grafts, which can significantly improve the functional properties of proteins. This is closely related to protein structural modification. Reports have investigated the grafting reaction of zein with dextran, as well as the structure and emulsifying properties of the grafts, finding that the zein-dextran graft exhibits better emulsifying properties compared to zein itself. Summary of the Invention:

[0004] The purpose of this invention is to provide a method for improving the emulsifying properties of zein grafts.

[0005] This invention is achieved through the following technical solutions:

[0006] A method for improving the emulsifying properties of zein-grafted products includes the following steps: during the preparation of an emulsion from zein-dextran grafted products, anti-dextran monoclonal antibody D24 is added.

[0007] Specifically, the steps include: take the zein-dextran graft, add phosphate buffer, stir until dissolved, add sodium azide, stir at room temperature, place at 0-4℃ for 12-20 hours, then add anti-dextran monoclonal antibody D24 and corn germ oil, and homogenize and emulsify at high speed using a high-speed homogenizer to obtain an emulsion.

[0008] Preferably, the amount of anti-dextran monoclonal antibody D24 added is 0.1-1 times the amount of zein-dextran graft material; more preferably, the amount of anti-dextran monoclonal antibody D24 added is 1 / 3-1 times the amount of zein-dextran graft material.

[0009] The anti-dextran monoclonal antibody D24 was produced by the dextran hybridoma cell line D24 with accession number CGMCC No.21002, as detailed in authorized patent 202011342789.0.

[0010] The beneficial effects of the present invention are as follows: The present invention improves the emulsifying properties of zein-dextran graft emulsion. Detailed implementation method:

[0011] The following is a further description of the invention, but not a limitation thereof.

[0012] Example 1: Preparation of Emulsion

[0013] Take 75 mg of zein-dextran graft and add 15 mL of 0.1 mol / L phosphate buffer (pH 7.5), stirring until dissolved. Add 3 mg of sodium azide, stir magnetically at room temperature for 2 h, and incubate at 4 °C for 16 h. Mix the above solution with 25 mg of anti-dextran monoclonal antibody D24 and 5 mL of corn germ oil, and homogenize using a high-speed homogenizer at 12000 r / min for 1 min to obtain emulsion B.

[0014] The preparation of the zein-dextran graft is based on existing technology and includes the following steps: 1g of zein (purchased from Bailingwei Technology Co., Ltd.) is dispersed in 99g of KCl-NaOH buffer (0.2mol / L, pH 12.0), and magnetically stirred at room temperature for 1h to fully dissolve the protein. 0.5g of dextran (70kDa, purchased from Sigma-Aldrich, USA) is added, and the mixture is magnetically stirred until homogeneous. The solution is then heat-treated in an 85℃ water bath for 2h, cooled to room temperature in an ice bath, centrifuged, and the supernatant is collected. The pH is adjusted to 7.0, dialyzed at 4℃ for 24h, and freeze-dried to obtain the zein-dextran graft.

[0015] Comparative Example 1:

[0016] Referring to Example 1, the difference is that the anti-dextran monoclonal antibody D24 was not added.

[0017] Take 75 mg of zein-dextran graft and add 15 mL of 0.1 mol / L phosphate buffer (pH 7.5), stirring until dissolved. Add 3 mg of sodium azide, stir magnetically at room temperature for 2 h, and let stand at 4 °C for 16 h. Mix the above solution with 5 mL of corn germ oil and homogenize using a high-speed homogenizer at 12000 r / min for 1 min to obtain emulsion A.

[0018] Example 2: Preparation of Emulsion

[0019] Take 75 mg of zein-dextran graft and add 15 mL of 0.1 mol / L phosphate buffer (pH 7.5), stirring until dissolved. Add 3 mg of sodium azide, stir magnetically at room temperature for 2 h, and incubate at 4 °C for 16 h. Mix the above solution, 75 mg of anti-dextran monoclonal antibody D24, and 5 mL of corn germ oil, and homogenize using a high-speed homogenizer at 12000 rpm for 1 min to obtain emulsion C.

[0020] The preparation of the zein-dextran graft is described in Example 1.

[0021] Example 3: Comparison of the emulsifying properties of emulsions A, B, and C

[0022] The emulsions prepared in Examples 1, 2, and Comparative Example 1 were sampled at 0 and 30 min, with 50 μL samples taken from the bottom of the test tubes. Each sample was diluted 100-fold with 0.1% sodium dodecyl sulfate solution. The absorbance of the samples was measured at 500 nm using a Spectra Max 190 microplate reader, with the 0.1% sodium dodecyl sulfate solution as a blank. The emulsifying activity (EAI) and emulsifying stability (ESI) were calculated using the following formulas:

[0023]

[0024]

[0025] In the formula, A0 and A 30 The absorbance values ​​are at 0 and 30 min, respectively; DF is the dilution factor (100); C is the protein concentration, g / mL. The percentage of the oil phase in the emulsion is 0.25.

[0026] The results are as follows:

[0027] <![CDATA[Emulsifying activity (m 2 / g)]]> Emulsification stability (min) Emulsion A of Comparative Example 1 16.57±0.55 26.61±0.85 Emulsion B of Example 1 18.50±0.62 29.11±0.84 Emulsion C of Example 2 17.82±0.56 28.84±0.75

[0028] Note: The significance test (t-test) showed that both examples were significantly different from the two indicators of the comparative example.

[0029] It is evident that emulsions B and C in Examples 1 and 2 exhibit improved emulsifying properties due to the addition of anti-dextran monoclonal antibody D24. The inventors hypothesize that because this antibody is a multivalent antibody, it can bind to multiple dextran chains, thereby enhancing the stability of the interfacial film formed during emulsification and thus improving the emulsifying properties of the grafted material.

Claims

1. A method for improving the emulsification properties of a zein graft, characterized in that, In the process of preparing emulsion by using zein-dextran graft, anti-dextran monoclonal antibody D24 is added, and the anti-dextran monoclonal antibody D24 is produced by the dextran hybridoma cell strain D24 with the preservation number of CGMCC No.21002.

2. The method of claim 1, wherein, Specifically comprising the following steps: Zein-dextran graft is taken, phosphate buffer is added, stirring is conducted until the zein-dextran graft is dissolved, sodium azide is added, stirring is conducted at room temperature, the mixture is placed at 0-4℃ for 12-20 hours, then the anti-dextran monoclonal antibody D24 is added and mixed with corn germ oil, and high-speed homogenization is conducted to obtain the emulsion.

3. The method of claim 1, wherein, The added amount of the anti-dextran monoclonal antibody D24 is 0.1-1 times the mass of the zein-dextran graft.

4. The method of claim 1, wherein, The added amount of the anti-dextran monoclonal antibody D24 is 0.1-1 times the mass of the zein-dextran graft. The added amount of the anti-dextran monoclonal antibody D24 is 0.1-1 times the mass of the zein-dextran graft.

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