Lac / ferrous ion / tannin aerogel deoxidizer and preparation method thereof

Abstract

The invention discloses a shellac / ferrous ion / tannin aerogel deoxidizer and a preparation method thereof, and belongs to the technical field of food deoxidizers. The preparation method comprises the following steps: mixing shellac, tannin and an alkaline solution to obtain a shellac / tannin mixed solution, adding a solution containing ferrous ions, and drying after the solution is gelatinized to obtain the shellac / ferrous ion / tannin aerogel deoxidizer. According to the shellac / ferrous ion / tannin aerogel deoxidizer prepared by the invention, ferrous ions and tannin are used as active ingredients of the deoxidizer, and shellac is used as a matrix. The aerogel deoxidizer provided by the invention is low in density and high in porosity, and the contact area of ferrous ions and tannin with oxygen is large, so that the deoxidization reaction is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of food deoxidizers, and particularly relates to a shellac / ferrous ion / tannin aerogel deoxidizer and a preparation method thereof. Background Art

[0002] Deoxidizers, also known as deoxidizers or oxygen absorbers, are a type of additive that can absorb oxygen and slow down the oxidation of food. The importance of deoxidizers lies in their ability to provide an oxygen-free or low-oxygen environment, thereby maintaining product quality and extending its shelf life. Deoxidizers can be roughly divided into two categories: inorganic deoxidizers and organic deoxidizers according to their chemical composition. Inorganic deoxidizers are generally based on iron powder or sulfite. Organic deoxidizers are mainly divided into three categories. The first category is ascorbic acid deoxidizers, which have a fast deoxidation speed, but also have disadvantages such as high cost and the need for metal catalysts; the second category is α-tocopherol deoxidizers, which usually need to be combined with transition metal catalysts such as iron, copper, manganese and cobalt for deoxidation; the third category is biological enzyme deoxidizers, which require a mild deoxidation condition. Temperature and pH value will affect the deoxidation efficiency of the enzyme, and the deoxidation conditions are relatively harsh.

[0003] Tannin is a natural plant polyphenol with a wide variety of species, widely distributed in the fruits, berries, leaves and flowers of woody and non-woody plants. Tannin can be divided into two categories according to its chemical structure: hydrolyzed tannin and condensed tannin. Hydrolyzed tannin is also called gallate tannin, such as gallnut tannin, tara tannin, oak tannin, etc.; condensed tannin is also called polyflavanol tannin, such as bayberry tannin, larch tannin, quebracho tannin, black wattle tannin, etc. At present, the research on tannin mainly focuses on the antibacterial property, astringency, and complexation of tannin. There are no reports on the deoxidation of tannin and tannin deoxidizer. Summary of the invention

[0004] The object of the present invention is to provide a shellac / ferrous ion / tannin aerogel deoxidizer and a preparation method thereof. The aerogel deoxidizer provided by the present invention has ferrous ions and tannin as active ingredients of the deoxidizer and shellac as a matrix. The provided aerogel deoxidizer has low density and high porosity, wherein the contact area between ferrous ions and tannin and oxygen is large, which is conducive to the deoxidation reaction.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a method for preparing a shellac / ferrous ion / tannin aerogel deoxidizer, comprising the following steps:

[0007] Mixing shellac, tannin and alkaline solution to obtain a shellac / tannin mixed solution, adding a solution containing ferrous ions, and drying the solution after gelation to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

[0008] Preferably, the tannin is one or more of gallnut tannin, bayberry tannin, larch tannin, black wattle tannin and quebracho tannin.

[0009] The tannins of the present invention are preferably from a wide range of sources, are easy to obtain, and are low in cost. Other tannins besides the above tannins can also achieve the technical purpose of the present invention.

[0010] Preferably, the concentration of shellac in the shellac / tannin mixed solution is 3-8 wt.%, and the concentration of tannin is 2-10 wt.%.

[0011] Preferably, the added amount of the ferrous ions does not exceed 1 times the molar amount of the shellac.

[0012] The source of ferrous ions in the present invention is soluble ferrous salts, including but not limited to one or more of ferrous sulfate, ferrous chloride and ferrous nitrate.

[0013] Preferably, the drying method is freeze drying.

[0014] The second technical solution of the present invention is to provide a shellac / ferrous ion / tannin aerogel deoxidizer prepared according to the preparation method of the shellac / ferrous ion / tannin aerogel deoxidizer.

[0015] The application conditions of the shellac / ferrous ion / tannin aerogel deoxidizer are: temperature 4-40° C. and relative humidity 40-100% RH.

[0016] The third technical solution of the present invention is to provide an application of the above-mentioned shellac / ferrous ion / tannin aerogel deoxidizer in a food deoxidizer.

[0017] The fourth technical solution of the present invention is to provide a deoxidizer, the components of which include the above-mentioned shellac / ferrous ion / tannin aerogel deoxidizer.

[0018] Preferably, the deoxidizer component further comprises sodium carbonate.

[0019] The sodium carbonate added in the present invention can provide an alkaline environment for the deoxygenation reaction of tannin, which is helpful for the ionization of protons in the tannin molecules, further improving the oxygen absorption characteristics of tannin and enhancing the deoxygenation effect.

[0020] More preferably, the sodium carbonate is sodium carbonate decahydrate or anhydrous sodium carbonate, and the added amount of sodium carbonate is no more than 3 times the mass of the shellac / ferrous ion / tannin aerogel deoxidizer.

[0021] The deoxidizer is applied under the following conditions: temperature 4-40° C., relative humidity 40-100% RH.

[0022] The beneficial technical effects of the present invention are as follows:

[0023] (1) The present invention proposes for the first time to combine tannin with ferrous ions as active ingredients of a deoxidizer, and simultaneously utilizes the reaction between ferrous ions and tannin and oxygen to consume oxygen in the air.

[0024] (2) The present invention induces shellac to generate shellac / ferrous ion / tannin aerogel by ferrous ions and tannins, and utilizes the characteristics of low density and high porosity of aerogel to increase the contact area between tannin and ferrous ions and oxygen, which is beneficial to the deoxygenation reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 1.

[0026] Figure 2 This is the SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 2.

[0027] Figure 3 This is the SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 3.

[0028] Figure 4 This is the SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 4. DETAILED DESCRIPTION

[0029] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0030] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0031] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] The molecular weight of the shellac used in the embodiment of the present invention is 1000 g / mol.

[0034] Example 1

[0035] (1) dissolving shellac in a 0.25 mol / L aqueous ammonia solution to obtain a shellac solution, wherein the mass concentration of the shellac is 8%;

[0036] (2) slowly adding a gallnut tannin aqueous solution (200 g / L) to the shellac solution, wherein the volume ratio of the tannin solution to the shellac solution is 0.92:1, and stirring the mixture to obtain a shellac / tannin mixed solution, wherein the mass ratio of tannin to shellac is 2.3:1;

[0037] (3) slowly adding ferrous sulfate solution to the shellac / tannin mixed solution obtained in the above step until it becomes a gel, wherein the molar ratio of ferrous ion to shellac is 0.1:1;

[0038] (4) The gel obtained in the above step is kept in dark for 1 hour, crushed and freeze-dried in dark to obtain shellac / ferrous ion / tannin aerogel powder, and passed through a 120-mesh sieve to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

[0039] The SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 1 is shown in Figure 1 .

[0040] Example 2

[0041] (1) dissolving shellac in a 0.025 mol / L sodium carbonate solution to obtain a shellac solution, wherein the mass concentration of the shellac is 8%;

[0042] (2) slowly adding a gallnut tannin aqueous solution (200 g / L) to the shellac solution and stirring evenly, wherein the volume ratio of the tannin solution to the shellac solution is 0.75:1, to obtain a shellac / tannin mixed solution, wherein the mass ratio of tannin to shellac is 1.88:1;

[0043] (3) slowly adding ferrous sulfate solution to the shellac / tannin mixed solution obtained in the above step until it becomes a gel, wherein the molar ratio of ferrous ion to shellac is 0.19:1;

[0044] (4) The gel obtained in the above step is kept in dark for 2 hours, crushed and freeze-dried in dark to obtain shellac / ferrous ion / tannin aerogel powder, and passed through a 120-mesh sieve to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

[0045] The SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 2 is shown in Figure 2 .

[0046] Example 3

[0047] (1) dissolving shellac in a 0.25 mol / L aqueous ammonia solution to obtain a shellac solution, wherein the mass concentration of the shellac is 8%;

[0048] (2) slowly adding a gallnut tannin aqueous solution (200 g / L) to the shellac solution and stirring evenly, wherein the volume ratio of the tannin solution to the shellac solution is 0.5:1, to obtain a shellac / tannin mixed solution, wherein the mass ratio of tannin to shellac is 1.25:1;

[0049] (3) slowly adding ferrous sulfate solution to the shellac / tannin mixed solution obtained in the above step until it becomes a gel, wherein the molar ratio of ferrous ion to shellac is 0.34:1;

[0050] (4) The gel obtained in the above step is kept in dark for 3 hours, crushed and freeze-dried in dark to obtain shellac / ferrous ion / tannin aerogel powder, and passed through a 120-mesh sieve to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

[0051] The SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 3 is shown in Figure 3 .

[0052] Example 4

[0053] (1) dissolving shellac in a 0.025 mol / L sodium carbonate solution to obtain a shellac solution, wherein the mass concentration of the shellac is 8%;

[0054] (2) slowly adding a gallnut tannin aqueous solution (200 g / L) to the shellac solution and stirring evenly, wherein the volume ratio of the tannin solution to the shellac solution is 0.25:1, to obtain a shellac / tannin mixed solution, wherein the mass ratio of tannin to shellac is 0.63:1;

[0055] (3) slowly adding ferrous sulfate solution to the shellac / tannin mixed solution obtained in the above step until it becomes a gel, wherein the molar ratio of ferrous ion to shellac is 0.42:1;

[0056] (4) The gel obtained in the above step is kept in dark for 1 hour, crushed and freeze-dried in dark to obtain shellac / ferrous ion / tannin aerogel powder, and passed through a 120-mesh sieve to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

[0057] The SEM image of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Example 4 is shown in Figure 4 .

[0058] Example 5

[0059] Compared with Example 2, only the tannin solution was not added, and all other steps were the same to prepare the shellac / ferrous ion aerogel.

[0060] The deoxidation amount of the shellac / ferrous ion / tannin aerogel deoxidizer prepared in Examples 1 to 5 alone or after mixing with sodium carbonate decahydrate under various conditions was measured. The measurement results are shown in Table 1.

[0061] Table 1 Deoxidation amount of each shellac / ferrous ion / tannin aerogel deoxidizer (mL / g)

[0062]

[0063] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a shellac / ferrous ion / tannin aerogel deoxidizer, characterized in that: The following steps are involved: Mixing shellac, tannin and alkaline solution to obtain a shellac / tannin mixed solution, adding a solution containing ferrous ions, and drying the solution after gelation to obtain a shellac / ferrous ion / tannin aerogel deoxidizer.

2. The method for preparing the shellac / ferrous ion / tannin aerogel deoxidizer according to claim 1, characterized in that: The tannin is one or more of gallnut tannin, bayberry tannin, larch tannin, black wattle tannin and quebracho tannin.

3. The method for preparing the shellac / ferrous ion / tannin aerogel deoxidizer according to claim 1, characterized in that: The concentration of shellac in the shellac / tannin mixed solution is 3-8 wt.%, and the concentration of tannin is 2-10 wt.%.

4. The method for preparing the shellac / ferrous ion / tannin aerogel deoxidizer according to claim 1, characterized in that: The added amount of the ferrous ions is no more than 1 times the molar amount of the shellac.

5. The method for preparing the shellac / ferrous ion / tannin aerogel deoxidizer according to claim 1, characterized in that: The drying method is freeze drying.

6. A shellac / ferrous ion / tannin aerogel deoxidizer prepared according to the method for preparing the shellac / ferrous ion / tannin aerogel deoxidizer according to any one of claims 1 to 5.

7. Use of the shellac / ferrous ion / tannin aerogel deoxidizer according to claim 6 as a food deoxidizer.

8. A deoxidizer, characterized in that The components comprise the shellac / ferrous ion / tannin aerogel deoxidizer as claimed in claim 6.

9. The deoxidizer according to claim 8, characterized in that The deoxidizer component further comprises sodium carbonate.

10. The deoxidizer according to claim 9, characterized in that The sodium carbonate is sodium carbonate decahydrate or anhydrous sodium carbonate, and the added amount of sodium carbonate is not more than 3 times the mass of the shellac / ferrous ion / tannin aerogel deoxidizer.

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