A kind of production and preparation method of low potassium carrageenan

Abstract

This invention discloses a method for producing low-potassium carrageenan, comprising the following steps: cleaning and drying *Euphorbia lactea* (a type of seaweed), then placing it in a mixed solution of NaHCO3 and NaOH for alkali treatment; cleaning the alkali-treated *Euphorbia lactea* until neutral; adding water to the cleaned *Euphorbia lactea* and heating to gel; filtering to obtain a low-potassium carrageenan solution; and subjecting the obtained low-potassium carrageenan solution to salting out, dehydration, drying, and pulverization. In this method, NaHCO3 is used instead of KCl in the alkali treatment process. The sodium ions in NaHCO3 can shield the negative charge of the sulfate groups, stabilizing the helical structure and promoting the aggregation of the helical structure into a three-dimensional network structure. This also promotes gelation, inhibits solution loss, and reduces the amount of KCl added during production, thereby lowering the potassium ion content in the carrageenan product.

Description

Technical Field

[0001] The invention relates to the technical field of carrageenan processing, and in particular to a production method for low-potassium carrageenan. Background Art

[0002] Carrageenan is a linear sulfated polysaccharide extracted from marine red algae. It is widely used as a food additive in the food industry because of its gelling, stabilizing, thickening and emulsifying properties.

[0003] At present, most of the processes for extracting carrageenan by domestic enterprises include: washing, alkali treatment, neutralization, boiling, filtering, salting out, dehydration, drying, crushing and other processes; among them, the alkali treatment process requires the addition of NaOH and KCl. The purpose of NaOH treatment is to remove the sulfate groups on the carrageenan molecular chain under alkaline conditions, thereby converting it into 3,6-endoether galactose to improve the gel strength of carrageenan; adding KCl is to use the sensitivity of carrageenan to potassium ions, and the electrostatic interaction and hydrogen bonding between carrageenan ion bonds and water molecules are weakened, which can effectively reduce the loss of carrageenan. However, the addition of KCl causes the potassium ions in the carrageenan products produced by enterprises to be high. The high potassium ions in the products are not only easy to cause chronic kidney diseases, allergies and cardiovascular diseases in the elderly, but also seriously affect the export sales of my country's carrageenan products. Summary of the invention

[0004] In order to solve the above problems, the embodiment of the present invention provides a method for producing a low-potassium carrageenan solution, which comprises the following steps:

[0005] The Eucheuma is washed, impurities removed, dried, and then placed in a mixed solution of NaHCO3 and NaOH for alkali treatment;

[0006] Wash the alkali-treated Eucheuma until it is neutral;

[0007] Add water to the washed Eucheuma and heat to make it gelatinous;

[0008] Filter to obtain low potassium carrageenan solution.

[0009] According to a method for producing a low-potassium carrageenan solution, NaHCO3 is used instead of KCl on the basis of an alkali treatment process. The sodium ions in NaHCO3 can shield the negative charge of the sulfate group of the carrageenan to stabilize the helical structure and promote the aggregation of the helical structure into a three-dimensional network structure, which can promote carrageenan gelation and inhibit the loss of the solution. At the same time, the amount of KCl added during the production and preparation process is reduced, thereby reducing the potassium ion content in the carrageenan product.

[0010] Optionally, during the alkali treatment, the mass fraction of the NaHCO3 is 10%-14% (w / v), and the mass fraction of the NaOH is 10% (w / v).

[0011] Optionally, during the alkali treatment, the solid-liquid ratio is 1:30 (w / v).

[0012] Optionally, during the alkali treatment, a water bath at 65° C. is required for 4 h.

[0013] Optionally, the gel was heated in a 100°C water bath for 4 h.

[0014] Optionally, the material-liquid ratio of the heated gel is 1:30 (w / v).

[0015] The embodiment of the present invention further provides a method for producing low potassium carrageenan powder, which comprises the steps included in any of the above-mentioned preparation methods, and further comprises the following steps:

[0016] The obtained low potassium carrageenan gelatin solution is subjected to salting out, dehydration, drying and pulverization.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The effect of different addition amounts of NaHCO3 on the yield of carrageenan products according to the embodiments of the present invention;

[0019] Figure 2 The effect of different addition amounts of NaHCO3 on the gel strength of carrageenan products according to the embodiments of the present invention;

[0020] Figure 3 The effect of different addition amounts of NaHCO3 on the viscosity of carrageenan products according to the embodiments of the present invention;

[0021] Figure 4 The effect of different addition amounts of NaHCO3 on the whiteness of carrageenan products according to the embodiments of the present invention;

[0022] Figure 5 The effect of different addition amounts of NaHCO3 on the elasticity of carrageenan products according to the embodiments of the present invention;

[0023] Figure 6 The figure shows the effect of different addition amounts of NaHCO3 on the potassium ion content of carrageenan products according to the embodiments of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0025] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0026] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0027] Extraction yield: The percentage of the dry weight of the carrageenan powder obtained after crushing to the dry weight of the raw material (Euchelina) is the carrageenan product yield;

[0028]

[0029] Wherein: m1 is the mass of finished carrageenan powder / g; m0 is the mass of Eucheuma raw material after drying / g.

[0030] Gel strength: Accurately weigh 1.5g of carrageenan powder, add it to 98.5g of 0.2% KCl solution, heat in a water bath to dissolve, pour into a 90mm diameter glass dish to cool and solidify, cover with plastic wrap, and let stand at 20℃ for 12h. Place the dish to be tested on the left tray of the tray balance, and adjust the cross-sectional area of ​​1cm 2 Fix the plunger just touching the gel surface, place the beaker on the right side of the tray balance, and slowly pour distilled water into the beaker continuously without interruption. Stop pouring water immediately after the gel surface breaks, and record the weight of the beaker and distilled water. The ratio of the weight of the beaker and distilled water to the cross-sectional area of ​​the plunger is the gel strength of the carrageenan product.

[0031]

[0032] Where: M is the total weight of distilled water and beaker / g; S is the cross-sectional area of ​​the plunger / cm 2 .

[0033] Viscosity: Referring to GB 1886.169-2016, weigh 7.5g of carrageenan product sample (accurate to 0.0002g), place it in a 600mL beaker with constant weight, add about 450mL of deionized water, and stir for 10min to 20min to allow the sample to fully diffuse. Add enough water to make the final solution mass reach 500g, heat it in a water bath and stir continuously. After 20min to 30min, the temperature rises to 80℃ and the heating is stopped. Add water to adjust the evaporation loss, cool to 76℃ to 77℃, and place it in a 75℃ constant temperature bath. Preheat the viscometer's pendulum and protective cover in water to 75℃, dry them, and install them in the viscometer. Measure with an NDJ-9S digital rotational viscometer. The unit is mPa. . s.

[0034] Whiteness: Pass the carrageenan product powder sample through a 80-mesh standard sieve and measure the whiteness using a whiteness meter.

[0035] Elasticity: Accurately weigh 1.5g of carrageenan powder, add it to 98.5g of 0.2% KCl solution, heat it in a water bath to dissolve, pour it into a glass dish with a diameter of 90mm, cool and solidify, cover it with plastic wrap, let it stand for 12 hours, and then measure it with a TA-touch texture analyzer. Parameter settings: P / 5 cylindrical probe, pre-test rate 1.0mm / s, test rate 1.0mm / s, post-test rate 5.0mm / s, strain 30%, trigger force 5g.

[0036] Potassium ion: Referring to GB 5009.91-2017, prepare 10 mg / mL KCl solution, and dilute it with distilled water to 0 mg / mL, 0.0625 mg / mL, 0.125 mg / mL, 0.25 mg / mL, and 0.5 mg / mL KCl standard working solution. Inject the KCl standard working solution into the atomic absorption spectrometer, measure the emission intensity, and draw a standard curve with the concentration of the standard working solution as the horizontal axis and the emission intensity as the vertical axis. Weigh the carrageenan powder and add water to make a 0.05 mg / mL solution, inject it into the atomic absorption spectrometer, measure the absorbance of the carrageenan powder, and calculate the potassium ion content in the carrageenan product according to the standard curve.

[0037] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0038] Example

[0039] In the alkali treatment process, NaHCO3 was used instead of KCl. The two groups adding KCl and NaOH solutions with mass fractions of 12% and 10% (w / v) respectively and the group adding only NaOH solution with mass fraction of 10% (w / v) were respectively as the positive control group and the negative control group. The five groups adding different mass fractions of NaHCO3 (3%, 6%, 9%, 12%, 15%, w / v) and 10% NaOH (w / v) solution were the experimental groups. The yield of extracted carrageenan powder, gel strength, viscosity, whiteness, elasticity and potassium ion content were measured, and the effect of using NaHCO3 instead of KCl in the alkali treatment process to extract and prepare carrageenan products was analyzed.

[0040] (1) Cleaning: Divide Eucheuma into groups of 20.0 g each, clean, remove impurities, dry and set aside.

[0041] (2) Alkali treatment: First, prepare 600 mL of a solution with a mass fraction of 12% KCl and 10% NaOH (w / v), and prepare solutions containing different mass fractions of NaHCO3 (0, 3%, 6%, 9%, 12%, 15%, w / v) and 10% NaOH (w / v), 600 mL per group, add cleaned Eucheuma into each solution at a solid-liquid ratio of 1:30 (w / v), and then incubate in a water bath at 65°C for 4 h.

[0042] (3) Neutralization: Collect the alkali-treated Eucheuma and wash it with plenty of running water until it becomes neutral.

[0043] (4) Boiling the glue: add distilled water to the washed and neutralized Eucheuma at a solid-liquid ratio of 1:30 (w / v), and place in a water bath at 100°C for 4 h.

[0044] (5) Filtration: Filter with double-layer cotton-padded 200-mesh filter cloth.

[0045] (6) Salting out: Slowly pour the filtered gel solution into 3 times the volume of 5% KCl (w / v) solution while stirring.

[0046] (7) Dehydration: Pressing and dehydration removes most of the water in the carrageenan after salting out.

[0047] (8) Drying: Dry at 60°C until constant weight.

[0048] (9) Crushing: crush with a crusher and then sieve to obtain carrageenan powder.

[0049] The results are as follows Figure 1As shown, the yield of the positive control group (12% KCl, 10% NaOH, w / v) was the highest, with a maximum yield of 53.18%; the yield of the negative control group (10% NaOH, w / v) was the lowest, with a minimum yield of 12.96%. In the experimental group, the yield of carrageenan increased with the increase of the mass fraction of NaHCO3. When the addition amount was 15% NaHCO3 (w / v), the yield of carrageenan decreased slightly. The yield of the experimental group with an addition amount of 12% NaHCO3 (w / v) was 48.04%, which was not significantly different from the highest yield, that is, the positive control group (12% KCl, 10% NaOH, w / v). This shows that it is feasible to use NaHCO3 instead of KCl to extract and produce carrageenan.

[0050] The results are as follows Figure 2 As shown in Figure 2, the gel strength of the positive control group (12% KCl, 10% NaOH, w / v) was the highest, reaching 902.1 g / cm 2 In the experimental group, the gel strength of the carrageenan product first increased and then decreased with the increase of the mass fraction of NaHCO3. The gel strength of the carrageenan product in the experimental group with an addition amount of 12% NaHCO3 (w / v) reached a maximum of 834.2 g / cm 2 .

[0051] Viscosity belongs to the category of rheology and is an important characteristic of polymer solutions. Under high temperature conditions, carrageenan fully dissolves in aqueous solution to form a viscous, slippery or jelly-like macromolecular substance, which plays a role in thickening and viscosity and increasing adhesion in food processing. Figure 3 As shown in the experimental group, the viscosity of the carrageenan product increased with the increase of the mass fraction of NaHCO3, and the viscosity of the experimental group with 12% NaHCO3 (w / v) added and the positive control group (12% KCl, 10% NaOH, w / v) were 8.46 mPa s and 1.24 mPa s, respectively. . s, 9.15mPa . s, there is no significant difference between the two.

[0052] Whiteness is an important physical and chemical index of carrageenan products. Adding high-whiteness carrageenan to food can give the food a higher commercial value. Figure 4 As shown, the negative control group (10% NaOH, w / v) had the highest whiteness, up to 74.71%. In the experimental group, the whiteness of the carrageenan product samples decreased with the increase of the mass fraction of NaHCO3. There was no significant difference between the whiteness of the samples with added amounts of 9% NaHCO3 and 12% NaHCO3 (w / v) (68.41%, 67.79%) and the whiteness of the samples in the positive control group (12% KCl, 10% NaOH, w / v) (69.68%).

[0053] like Figure 5 As shown, in the experimental group, the elasticity of the carrageenan product samples increased with the increase of the mass fraction of NaHCO3. When the added amount was 12% NaHCO3 (w / v), the elasticity of the carrageenan product samples was the highest, reaching 0.9116, and there was no significant difference between the positive control group (12% KCl, 10% NaOH, w / v).

[0054] like Figure 6 As shown in the figure, the potassium ion contents in the carrageenan samples of the positive control group (12% KCl, 10% NaOH, w / v) and the negative control group (10% NaOH, w / v) were 0.676% and 0.781%, respectively. This indicates that the potassium ions in the carrageenan are mainly introduced during the salting-out process, and a small part is caused by the addition of KCl during the alkali treatment to inhibit the loss of the gel solution. The high potassium ion content in the negative control group may be due to the serious loss of the gel solution in the control group without adding KCl, the low gel solution concentration, and the unstable structure of the carrageenan gel solution. The structurally unstable gel solution may require more potassium ions to aggregate the gel solution to form a stable network structure and then form a gel. After squeezing and dehydration, the water content of the carrageenan block is about 80%-85%, and a large amount of potassium ions remain in the carrageenan block with water, so there are still more potassium ions in the gel sample of the control group without adding KCl. In the experimental group, the potassium ion content continued to decrease, and it was the lowest when the added amount was 12% NaHCO3 (w / v). At this time, the potassium ion content was 0.642%, which was 17.80% less than the traditional process, i.e. the positive control group (12% KCl, 10% NaOH, w / v) sample, indicating that the addition of sodium ions can effectively reduce the potassium ion content of carrageenan products; in addition, potassium ions are more harmful to the human body than sodium ions, indicating the feasibility of using NaHCO3 instead of KCl in this research process.

[0055] In summary, according to the method of the embodiment of the present invention, NaHCO3 is used instead of KCl in the alkali treatment process, and the sodium ions in NaHCO3 can replace the potassium ions to shield the negative charge of the sulfate group and stabilize the helical structure, and promote the helical structure to aggregate into a three-dimensional network structure, which can promote gelation and inhibit the loss of gel, while reducing the amount of KCl added during the production and preparation of carrageenan products, thereby reducing the potassium ion content in the carrageenan product, and when the mass fraction of NaHCO3 is 10%-14%, it does not affect the yield, gel strength, viscosity, whiteness, and elasticity of the carrageenan product.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0057] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for producing a low-potassium carrageenan solution, characterized in that: The following steps are involved: Washing, removing impurities, drying and placing Eucheuma in a mixed solution of NaHCO3 and NaOH for alkali treatment; the mass fraction of the NaHCO3 is 10%-14% w / v, and the mass fraction of the NaOH is 10% w / v; Wash the alkali-treated Eucheuma until it is neutral; Add water to the washed Eucheuma and heat to make it gelatinous; Filter to obtain low potassium carrageenan solution.

2. The preparation method according to claim 1, characterized in that During the alkali treatment, the solid-liquid ratio was 1:30 w / v.

3. The preparation method according to claim 1, characterized in that: During the alkali treatment process, it is necessary to place it in a water bath at 65°C for 4 hours.

4. The preparation method according to claim 1, characterized in that: The gel was heated in a 100°C water bath for 4 h.

5. The preparation method according to claim 1, characterized in that: The material-liquid ratio of heated glue is 1:30w / v.

6. A method for preparing low potassium carrageenan powder, characterized in that: The preparation method according to any one of claims 1 to 5 further comprises the following steps: The obtained low potassium carrageenan gelatin solution is subjected to salting out, dehydration, drying and pulverization.

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