A method for removing impurities from Iota type carrageenan solution

Abstract

The invention discloses an impurity removal method for Iota carrageenan glue liquid, which comprises the following steps: salting out the glue liquid obtained by heating the glue liquid; and dehydrating the glue liquid after the salting out by alcohol impurity removal. The method adopts an impurity removal process combining salting out with alcohol impurity removal and dehydration to remove impurities from the Iota carrageenan crude glue liquid, has a simple process, mild conditions, significantly reduces the amount of organic solvent used, improves transparency, is green and environmentally friendly, reduces pollution to the environment, reduces costs and conforms to the development trend of green industry.

Description

Technical Field

[0001] The invention relates to the technical field of carrageenan processing, and in particular to a method for removing impurities from an Iota type carrageenan solution. Background Art

[0002] Carrageenan is a type of linear, high-molecular polysaccharide containing sulfate groups extracted from seaweed. Its basic skeleton is composed of 1,3-β-D-galactopyranose and 1,4-α-D-galactopyranose alternately connected. As a hydrophilic natural plant colloid, carrageenan has a very wide range of applications in the food industry due to its thickening, gelling, and emulsifying properties. Currently, the three types of carrageenan, κ, ι and λ, are the most common in commercial use. Compared with the hard and brittle gel of κ-carrageenan, the gel formed by Iota carrageenan is softer and more elastic. These two thermoreversible gels can have different application scenarios in the food industry.

[0003] Traditionally, the extraction of Iota-type carrageenan in the industry mainly adopts the alkaline extraction method. The raw material, I-type Eucheuma, has a short growth cycle, high yield, and is easy to cultivate. Its price is cheaper than that of the raw material of κ-carrageenan, Eucheuma auriculata. However, a large amount of alcohol is used for precipitation during the extraction process of Iota-type carrageenan, which increases the production cost and the environmental burden. In addition, the transparency of Iota-type carrageenan is limited. Summary of the invention

[0004] In order to solve the above problems, an embodiment of the present invention provides a method for removing impurities from an Iota type carrageenan solution, which comprises the following steps:

[0005] The glue solution obtained by heating the glue is subjected to salting-out treatment; the glue solution after the salting-out treatment is dehydrated by using industrial alcohol to remove impurities.

[0006] According to an embodiment of the present invention, a method for removing impurities from an Iota type carrageenan solution is disclosed. The method adopts a salting-out method combined with an alcohol impurity removal and dehydration process to remove impurities from the Iota type carrageenan crude solution. The process is simple, the conditions are mild, the amount of organic solvent used is significantly reduced, and the transparency is improved. The method is green and environmentally friendly, and the pollution to the environment is reduced, thereby reducing costs and complying with the development trend of the green industry.

[0007] Optionally, the salt solution is a NaCl solution or a KCl solution.

[0008] Furthermore, the concentration of the salt solution is 3% W / V to 7% W / V.

[0009] Furthermore, the concentration of the saline solution is 5% W / V.

[0010] Optionally, the ratio of the glue solution to the saline solution is 1:3-7.

[0011] Furthermore, the ratio of the glue solution to the saline solution is 1:5.

[0012] Optionally, the salting-out treated glue solution is dehydrated by using industrial alcohol, and the ratio of the product to the alcohol is 1:0.7-3.

[0013] Furthermore, the ratio of the glue solution to the saline solution is 1:1.

[0014] Optionally, the salting-out treatment further includes:

[0015] Raw material cleaning: Take dry type I Eucheuma, add 25-50 times water to clean and remove impurities;

[0016] Alkali treatment: prepare a mixed treatment solution of NaOH and KCl, perform alkalization treatment on the washed type I Eucheuma, and rinse until neutral;

[0017] Acidification treatment: prepare hydrochloric acid solution, acidify the rinsed type I Eucheuma, and rinse until neutral.

[0018] Furthermore, in the alkali treatment step, the material-liquid ratio is 1:30, the treatment temperature is 40-45° C., and the treatment time is 2-3 hours.

[0019] Furthermore, in the alkali treatment step, the concentration of the NaOH solution is 7% W / V to 10% W / V, and the concentration of the KCl solution is 10% W / V to 12% W / V.

[0020] Furthermore, in the acidification step, the concentration of hydrochloric acid is 0.30% V / V to 0.50% V / V, and the treatment time is 45 minutes.

[0021] Optionally, after the alcohol is used to remove impurities and dehydrate, the process further includes filtering, drying, crushing and sieving the carrageenan solution to obtain an Iota carrageenan finished product.

[0022] 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

[0023] Figure 1 This is a comparison chart of the transparency and gel strength of finished products with different salt contents in the examples of the present invention and the comparative examples;

[0024] Figure 2 A comparison chart of transparency and gel strength of finished products with different salt solution ratios in the examples of the present invention and the comparative examples;

[0025] Figure 3 This is a comparison chart of transparency and gel strength of finished products with different alcohol ratios in the examples of the present invention and the comparative examples;

[0026] Figure 4 A comparison chart of transparency and gel strength of finished products with different salt concentrations in the examples of the present invention and the comparative examples;

[0027] Figure 5 Comparison of the transparency of gels of different concentrations in the examples and comparative examples of the present invention. DETAILED DESCRIPTION

[0028] 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.

[0029] 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.

[0030] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0031] Transparency determination: Prepare a 1.5% (w / v) iota-carrageenan solution containing 0.2% calcium chloride, cool it at 25°C for 12 hours, and then measure the transmittance of the gel at a wavelength of 700 nm. Distilled water is used as a blank control group, and the transmittance value represents the transparency.

[0032] 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.

[0033] Example 1

[0034] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0035] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0036] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, treat the rinsed type I Eucheuma with acidification for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0037] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use NaCl solution to salt out the glue solution for 15 minutes, the concentration of NaCl solution is 3% to 7% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0038] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0039] Example 2

[0040] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0041] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0042] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0043] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use KCl solution to salt out the glue solution for 15 minutes, the concentration of KCl solution is 3% to 7% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0044] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0045] Example 3

[0046] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0047] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0048] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, treat the rinsed type I Eucheuma with acidification for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0049] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use NaCl solution to salt out the glue solution for 15 minutes, the concentration of NaCl solution is 5% (W / V), the ratio of glue solution to salt solution is 1:3-7; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0050] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0051] Example 4

[0052] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0053] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0054] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, treat the rinsed type I Eucheuma with acidification for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0055] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use KCl solution to salt out the glue solution for 15 minutes, the concentration of KCl solution is 5% (W / V), the ratio of glue solution to salt solution is 1:3-7; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0056] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0057] Example 5

[0058] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0059] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0060] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, treat the rinsed type I Eucheuma with acidification for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0061] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use NaCl solution to salt out the glue solution for 15 minutes, the concentration of NaCl solution is 5% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:0.7~3.

[0062] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0063] Example 6

[0064] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0065] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0066] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, treat the rinsed type I Eucheuma with acidification for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0067] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use KCl solution to salt out the glue solution for 15 minutes, the concentration of KCl solution is 5% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:0.7~3.

[0068] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0069] Example 7

[0070] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0071] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0072] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0073] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use NaCl solution to salt out the glue solution for 15 minutes, the concentration of NaCl solution is 5% (W / V), use NaCl solution to salt out the glue solution for 15 minutes, the concentration of NaCl solution is 5% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0074] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0075] Sol: Dissolve iota-carrageenan at 1%, 2% and 3% concentration and test its transparency.

[0076] Example 8

[0077] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0078] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0079] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0080] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100°C for 4 hours, filter to obtain glue solution, use KCl solution to salt out the glue solution for 15 minutes, the concentration of KCl solution is 5% (W / V), and the ratio of glue solution to salt solution is 1:5; after filtration, use alcohol to remove impurities and dehydrate for 30 minutes, and the ratio of glue solution to alcohol is 1:1.

[0081] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0082] Sol: Dissolve iota-carrageenan at 1%, 2% and 3% concentration and test its transparency.

[0083] Comparative Example 1

[0084] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0085] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0086] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes at a material-liquid ratio of 1:30, filter out the acid solution, and rinse with clean water until neutral.

[0087] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100℃ for 4 hours, filter to obtain the glue solution, use alcohol to remove impurities and dehydrate the glue solution for 15 minutes, the ratio of glue solution to alcohol is 1:3.

[0088] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0089] Comparative Example 2

[0090] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0091] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0092] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio is 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0093] Impurity removal treatment: heat the gel, boil the gel in a water bath at 100°C for 4 hours, filter to obtain gel solution, and use KCl solution to salt out the gel solution for 15 minutes. The concentration of KCl solution is 5% (W / V), and the ratio of gel solution to salt solution is 1:5.

[0094] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0095] Comparative Example 3

[0096] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0097] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0098] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0099] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100℃ for 4h, filter to obtain glue solution, add 0.10%-0.40% (W / V) NaCl to the glue solution, stir evenly, use alcohol to remove impurities and dehydrate the glue solution for 30min, the ratio of glue solution to alcohol is 1:3.

[0100] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0101] Comparative Example 4

[0102] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0103] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0104] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (solid-liquid ratio 1:30), filter out the acid solution, and rinse with clean water until neutral.

[0105] Impurity removal treatment: heat the glue, boil the glue in a water bath at 100℃ for 4h, filter to obtain glue solution, add 0.10%-0.40% (W / V) KCl to the glue solution, stir evenly, use alcohol to remove impurities and dehydrate the glue solution for 30min, the ratio of glue solution to alcohol is 1:3.

[0106] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0107] Comparative Example 5

[0108] Raw material cleaning: Take 30 g of dry type I Eucheuma, add 900 mL of water to clean and remove impurities.

[0109] Alkali treatment: prepare 900 mL of a mixed treatment solution of 10% (W / V) NaOH and 12% (W / V) KCl, and alkalize the washed type I Eucheuma (solid-liquid ratio is 1 g / 30 mL), place it in a constant temperature water bath at 43°C for 2.5 h, filter out the alkali solution, and rinse with clean water until neutral.

[0110] Acidification treatment: prepare 0.40% (V / V) hydrochloric acid solution, acidify the rinsed type I Eucheuma for 45 minutes (1:30), filter out the acid solution, and rinse with clean water until neutral.

[0111] Impurity removal treatment: heat the glue (cook the glue in a water bath at 100°C for 4 hours), filter to obtain the glue solution, and use alcohol to remove impurities and dehydrate the glue solution (30 minutes), with the ratio of glue solution to alcohol being 1:3.

[0112] Finished product: After removing impurities, it is dried, crushed, and passed through an 80-mesh sieve to obtain the Iota type carrageenan finished product.

[0113] Sol: Dissolve iota-carrageenan at 1%, 2% and 3% concentration and test its transparency.

[0114] Test example

[0115] Performance tests were performed on the products obtained from Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, Example 8, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4.

[0116] Table 1 (different salt content)

[0117]

[0118] Table 2 (ratios of different salt solutions)

[0119]

[0120] Table 3 (different alcohol ratios)

[0121]

[0122] Table 4 (Comparison of gel transparency at different concentrations (1%, 2%, 3%))

[0123]

[0124]

[0125] The results are shown in Table 1, Table 2, and Table 3. Figure 1 , Figure 2 , Figure 3 The Iota carrageenan obtained by the method of the present application has a significantly improved transparency compared with the finished product that has not been subjected to salting-out treatment (Comparative Example 1) and the finished product that has not been subjected to alcohol precipitation and salting-out treatment (Comparative Example 2), on the premise that its gel strength does not change significantly; the amount of alcohol used by the method of the present application is significantly reduced compared with the finished product that has not been subjected to salting-out treatment (Comparative Example 1), on the premise that its gel strength does not change significantly and its transparency is significantly improved.

[0126] The results are as follows Figure 4 The Iota carrageenan obtained by the method of the present application has a significantly improved transparency compared with the finished product obtained by directly adding salt to the glue solution and stirring it and then treating it with alcohol precipitation (Comparative Example 3), while its gel strength does not change significantly. In Comparative Example 3, 0.1% NaCl cannot form a gel at a concentration of 1.5%. Although the method of directly adding salt to the glue solution can also improve the transparency of the finished product to a certain extent, the degree of impurity removal is not as good as that of the method of the present application, and the high transparency of the finished product of the method of the present application cannot be achieved, and it will affect the formation of the gel, and the gel strength is lower.

[0127] The results are shown in Table 4. Figure 5 The transparency of the finished product without salting-out treatment (Comparative Example 1) and the Iota carrageenan finished product obtained by the method of the present application was compared at different concentrations. The transparency decreased with the increase of concentration. At each concentration, the transparency of the finished product of the method of the present application was significantly improved.

[0128] Salting out uses metal ions in inorganic salts to cross-link the ordered conformational regions in the crude gel solution to form a gel, which is then condensed and precipitated in a salt solution. After filtering out excess water from the precipitated gel blocks, ethanol is added to the gel blocks, making use of the fact that carrageenan is insoluble in ethanol, so that the carrageenan is precipitated. After a two-step separation and purification process, most of the impurities in the crude gel solution are removed and dehydrated, making the final product purer than traditional Iota carrageenan.

[0129] In the salting-out step, excessive metal ions, such as when the concentration of the salting-out solution in Examples 1 and 2 is as high as 7% (W / V), will cause gel aging and destroy the gel morphology. Not only will part of the carrageenan be lost with the water during dehydration, but the transparency of the final product will also be reduced. Therefore, the optimal concentration of the salting-out solution is 5% (W / V).

[0130] According to an embodiment of the present invention, a salting-out method combined with alcohol impurity removal and dehydration is used to remove impurities from the crude Iota carrageenan solution. The process is simple, the conditions are mild, the amount of organic solvent used is significantly reduced, and the transparency is improved. It is green and environmentally friendly, and the pollution to the environment is reduced, thereby reducing costs and complying with the development trend of the green industry.

[0131] 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.

[0132] 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 removing impurities from Iota type carrageenan solution, characterized in that: The following steps are involved: The glue solution obtained by heating the glue is subjected to salting-out treatment for 15 minutes; the ratio of the glue solution to the salt solution is 1:3-7; the concentration of the salt solution is 5% W / V; The glue solution after salting out is dehydrated by removing impurities with alcohol, and the ratio of glue solution to alcohol is 1:0.7-3.

2. The impurity removal method according to claim 1, characterized in that: The salt solution is a NaCl solution or a KCl solution.

3. The impurity removal method according to claim 1, characterized in that: Before salting out treatment, it also includes: Raw material cleaning: Take dry type I Eucheuma, add 25-50 times water to clean and remove impurities; Alkali treatment: prepare a mixed treatment solution of NaOH and KCl, perform alkalization treatment on the washed type I Eucheuma, and rinse until neutral; Acidification treatment: prepare hydrochloric acid solution, acidify the rinsed type I Eucheuma, and rinse until neutral.

4. The impurity removal method according to claim 3, characterized in that: In the alkali treatment step, the material-liquid ratio is 1:30, the treatment temperature is 40-45° C., and the treatment time is 2-3 hours.

5. The impurity removal method according to claim 3, characterized in that: In the alkali treatment step, the concentration of the NaOH solution is 7% W / V to 10% W / V, and the concentration of the KCl solution is 10% W / V to 12% W / V.

6. The impurity removal method according to claim 3, characterized in that: In the acidification step, the concentration of hydrochloric acid is 0.30% V / V to 0.50% V / V, and the treatment time is 45 minutes.

7. The impurity removal method according to claim 1, characterized in that: After alcohol removal and dehydration, the gum solution is filtered, dried, crushed and sieved to obtain the Iota carrageenan finished product.

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