Fagonia source water-soluble green and yellow pigment and preparation method thereof

Abstract

The application provides a water-soluble green-yellow pigment from sophora japonica and a preparation method thereof. According to Lab color model analysis, the water-soluble green-yellow pigment has an L value of 78-80, an a value of -6.5 to -9.0, and a b value of 43.0-44.5. The preparation method comprises the following steps: after maturation, the sophora japonica is subjected to fermentation, then is subjected to cracking treatment to make the petal of the sophora japonica crack, the cracked sophora japonica is mixed with an extraction solvent to perform extraction, and after crystallization of the obtained extraction liquid, solid-liquid separation is performed to obtain rutin and a mother liquor, wherein the mother liquor is the water-soluble green-yellow pigment. The water-soluble green-yellow pigment from sophora japonica has the advantages of good pigment stability, good dyeing performance, simple operation, easy availability of raw materials, low cost, no pollution, low requirement on equipment, and suitability for industrial large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of natural pigments, and particularly relates to a water-soluble green-yellow pigment from sophora flower bud and a preparation method thereof. BACKGROUND

[0002] In recent years, pigments are applied more and more widely, and there is an increasing demand for natural and safe pigments, which puts forward higher requirements for the pigment processing industry. At present, pigments can be mainly divided into two categories according to sources: natural pigments and synthetic dyes. Natural pigments are applied earlier, and are safer and more environmentally friendly, but have limitations such as limited content in nature, complex extraction process and high production cost. Synthetic pigments have the advantages of bright color and low production cost compared with natural pigments, but have the disadvantage that synthetic dyes have complex structures and are difficult to degrade in nature, which greatly damages the ecological environment. The above-mentioned shortcomings of natural pigments and synthetic pigments to some extent restrict the further development and application of the pigment industry.

[0003] Sophora flower bud, the dried flower bud of Sophora japonica L. of the Leguminosae family, has a long history of medicinal use. Sophora flower bud contains rutin, sophoraflavescens A, B, C and quercetin. Sophora flower bud is a commonly used traditional Chinese medicine with bitter taste and cold nature, and has the effects of cooling blood and stopping bleeding. In recent years, sophora flower bud is used for treating nosebleed and hypertension, is a commonly used medicinal material for extracting rutin in the pharmaceutical industry, and is also an important source of plant dyes.

[0004] The existing method for extracting natural pigments from sophora flower bud is mainly alkali extraction and acid precipitation, such as CN105647230A. Water extraction is also used, such as the research on extraction of sophora flower bud natural pigment and its dyeing process on silk by QI Qing et al. However, the pigments extracted by the existing methods are all yellow, and their dyeing performance on cotton fibers is poor, and the fastness needs to be improved. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a water-soluble green-yellow pigment from sophora flower bud and a preparation method thereof.

[0006] In a first aspect, the present application provides a water-soluble green-yellow pigment from sophora flower bud, which has an L value of 78-80, an a value of-6.5 to-9.0, and a b value of 43.0-44.5 according to Lab color model analysis.

[0007] In the process of developing refined rutin, this invention unexpectedly discovered that a novel water-soluble green-yellow pigment can be obtained simultaneously with the refined rutin obtained by the method of this invention. This pigment is different from the pigments extracted in the past that are mainly composed of rutin. According to Lab color model analysis, this pigment has an L value of 78-80, an a value of -6.5--9.0, and a b value of 43.0-44.5, which broadens the range of pigments. Moreover, it has good stability and excellent staining performance.

[0008] Furthermore, the E of the water-soluble green-yellow pigment 580 1％ 1cm ≥50, insoluble solids ≤0.1%.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned water-soluble green-yellow pigment.

[0010] The preparation method provided by this invention includes:

[0011] After the Sophora japonica flowers are cooked and then allowed to ferment, they are then subjected to a cracking process to cause the petals to split. The cracked Sophora japonica flowers are mixed with an extraction solvent for extraction. The extract is then crystallized, and after solid-liquid separation, rutin and mother liquor are obtained. The mother liquor is a water-soluble green-yellow pigment.

[0012] This invention does not impose any special restrictions on the raw materials of Sophora japonica flowers; freshly harvested, untreated Sophora japonica flowers or properly stored Sophora japonica flowers can be used.

[0013] Furthermore, the ripening temperature is 90-140℃ and the time is 20-60 minutes.

[0014] Controlling the ripening temperature and time within the above-mentioned range helps to reduce the loss of active ingredients such as rutin during the processing, and also better ensures the integrity of the Sophora japonica buds after the cracking treatment.

[0015] Furthermore, the final temperature of the proofing process is 50-70°C. The final moisture content of the proofing process is 10-15%.

[0016] The aforementioned final temperature for proofing refers to the temperature at the end of proofing, and the final moisture content refers to the moisture content of the Sophora japonica flowers at the end of proofing.

[0017] After high-temperature cooking, the buds are directly subjected to a proofing process until the aforementioned endpoint temperature and moisture content are reached. The proofing process involves placing the cooked buds under specific temperature and humidity conditions until the endpoint temperature and moisture content are reached.

[0018] The present invention does not impose any special restrictions on the equipment used for proofing. Those skilled in the art can choose to perform proofing under cooling water and / or nitrogen flow conditions as needed, as long as the above-mentioned proofing endpoint temperature and endpoint moisture content are achieved.

[0019] The present application finds that, if high-temperature curing is not followed by leavening and cracking treatment is directly performed, the viscosity of sophora flower bud will be large, making it difficult to perform cracking treatment. Further, controlling the end temperature and moisture of leavening within the above range can ensure cracking effect (causing the petal to split) while significantly improving the integrity of the sophora flower bud after cracking treatment, significantly reducing the leaching of macromolecular components such as polysaccharides, and being conducive to the control of the components of the mother liquor after rutin extraction.

[0020] Further, the cracking is performed by extrusion.

[0021] Extrusion cracking refers to a method of opening the to-be-treated object by extrusion. The present application does not have special restrictions on the equipment used for extrusion cracking, and conventional extrusion cracking equipment can be used.

[0022] In some embodiments of the present application, a roller mill is used for cracking treatment.

[0023] Further, the extraction solvent is 85%-95% methanol aqueous solution and / or 70%-80% ethanol aqueous solution.

[0024] Further, the extraction temperature is 55-70℃. Preferably, the extraction time is 1-10h. Preferably, the extraction method is continuous countercurrent.

[0025] The above extraction can be performed using conventional extraction equipment, and the number of extractions is not specially limited. According to the needs of industrialization, the number of extractions can be increased or a cyclic extraction method can be used.

[0026] In industrial applications, tanks, baskets, and flat turning can be used for extraction, and the extracted liquid can be concentrated and crystallized.

[0027] Further, the extraction liquid is concentrated to 1 / 4.5-1 / 7.5 of the original volume before crystallization.

[0028] Preferably, the crystallization is cooling and stirring crystallization, the crystallization time is 5-10h, and the end temperature of crystallization is 10-50℃.

[0029] Preferably, after crystallization, the wet crystals are obtained by solid-liquid separation, and the wet crystals are washed with the extraction solvent.

[0030] In a third aspect, the present application provides a green-yellow dye comprising a mordant and the above water-soluble green-yellow pigment.

[0031] The mordant and the pigment combine to form pigment precipitate to achieve the dyeing effect. The use of mordant can mix the mordant in the pigment liquid to dye, or use the mordant to dye the pre-treatment, then use the pigment liquid to dye, or use the pigment liquid to dye first, then use the mordant. The three methods are called same mordant, pre-mordant and post-mordant.

[0032] Preferably, the mordant is one or more of dichromate, aluminum salt, copper salt, cobalt salt, and the added amount is 2-5% (m / m) of the water-soluble green-yellow pigment.

[0033] In the preferred embodiment of the present application, the mordant is mixed in the pigment liquid to dye.

[0034] That is, the present application provides a preparation method of the above-mentioned green-yellow dye, comprising: mixing the water-soluble green-yellow pigment with a mordant, concentrating, and then adjusting the pH value to 5-6.

[0035] Preferably, the pH value is adjusted to 5-6 after being concentrated to a total solid content of 65%-70%.

[0036] In the fourth aspect, the present application provides the use of the above-mentioned water-soluble green-yellow pigment or green-yellow dye in paper dyeing or cloth dyeing.

[0037] The present application provides a water-soluble green-yellow pigment from sophora japonica and a preparation method thereof. The green-yellow pigment is a new type of natural green-yellow pigment, which has bright and harmonious color tone and can be applied to paper and cloth dyeing. In cloth dyeing, the dyeing performance and fastness are obviously better than other natural pigments. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0039] In the following examples, the experimental methods used are conventional methods unless otherwise specified. In the following examples, the materials, reagents, etc. used are commercially available or prepared according to conventional methods in the art unless otherwise specified.

[0040] The maturation device used in the preparation method of the present application can be selected from a disc dryer, a steaming and stripping machine, an oven, a distillation kettle, a frying pan or other devices that can uniformly heat. The leavening device can be selected from a disc dryer, a steaming and stripping machine, an oven, a distillation kettle, a frying pan or other devices that can uniformly control temperature. The leavening device can be configured according to the situation of the workshop equipment. If the equipment allows, the maturation equipment can be used for in-situ leavening. In order to exclude the influence of different equipment, all the examples and comparative examples below are carried out using uniform maturation and leavening equipment.

[0041] The sophora flower bud raw material used in the following examples is fresh sophora flower bud.

[0042] Example 1

[0043] The present example provides a sophora flower bud-derived water-soluble green-yellow pigment, and the preparation method thereof is as follows:

[0044] The sophora flower bud is sent to a first steaming and stripping machine for maturation at a temperature of 140°C for 20 min. Then, the sophora flower bud is transferred to a second steaming and stripping machine for leavening in a closed state by a feeding scraper. The leavening end temperature is 59-61°C, and the leavening end moisture is 13.0-13.5%. After leavening, the sophora flower bud is cracked by a roller machine to make the petals of the sophora flower bud crack. The cracked sophora flower bud is extracted with 70% ethanol at an extraction temperature of 60°C. The extraction is carried out 5 times under the same conditions. The extract is combined and concentrated to 1 / 4.5 of the original volume. Then, the extract is cooled and stirred to crystallize. The crystallization time is 5 h, and the crystallization end temperature is 50°C. Rutin and a mother liquor are obtained by solid-liquid separation. The obtained mother liquor is the target sophora flower bud-derived water-soluble green-yellow pigment.

[0045] Example 2

[0046] The present example provides a sophora flower bud-derived water-soluble green-yellow pigment, and the preparation method thereof is as follows:

[0047] The sophora flower bud is sent to a first steaming and stripping machine for maturation at a temperature of 120°C for 40 min. Then, the sophora flower bud is transferred to a second steaming and stripping machine for leavening in a closed state by a feeding scraper. The leavening end temperature is 59-61°C, and the leavening end moisture is 13.0-13.5%. After leavening, the sophora flower bud is cracked by a roller machine to make the petals of the sophora flower bud crack. The cracked sophora flower bud is extracted with 90% methanol at an extraction temperature of 65°C. The extraction is carried out 5 times under the same conditions. The extract is combined and concentrated to 1 / 7.5 of the original volume. Then, the extract is cooled and stirred to crystallize. The crystallization time is 10 h, and the crystallization end temperature is 10°C. Rutin and a mother liquor are obtained by solid-liquid separation. The obtained mother liquor is the target sophora flower bud-derived water-soluble green-yellow pigment.

[0048] Example 3

[0049] The present example provides a sophora flower bud-derived water-soluble green-yellow pigment, and the preparation method thereof is as follows:

[0050] The sophora fruit is sent to a first steaming and stripping machine for maturation, the maturation temperature is 90℃, the maturation time is 60 min, then the sophora fruit is transferred to a second steaming and stripping machine for fermentation in a closed state by a feeding scraper, the fermentation end point temperature is 59-61℃, the fermentation end point moisture is 13.0-13.5%, after fermentation, the sophora fruit is cracked by a roller machine to make the petal of the sophora fruit crack, the cracked sophora fruit is extracted by 80% ethanol, the extraction temperature is 60℃, the extraction is carried out 5 times under the same condition, the extract is combined and concentrated to 1 / 6 of the original volume, then the temperature is reduced for stirring and crystallization, the crystallization time is 8 h, the end point temperature of crystallization is 20℃, rutin and mother liquor are obtained by solid-liquid separation, and the obtained mother liquor is the target water-soluble green-yellow pigment.

[0051] Comparative Example 1

[0052] The present comparative example provides a pigment preparation method, which is specifically as follows:

[0053] The sophora fruit is directly cracked by a roller machine to make the petal of the sophora fruit crack, the cracked sophora fruit is extracted by 70% ethanol, the extraction temperature is 60℃, the extraction is carried out 5 times under the same condition, the extract is combined and concentrated to 1 / 4.5 of the original volume, then the temperature is reduced for stirring and crystallization, the crystallization time is 5 h, the end point temperature of crystallization is 50℃, rutin and mother liquor are obtained by solid-liquid separation, and the obtained mother liquor is the pigment product.

[0054] Comparative Example 2

[0055] The present comparative example provides a pigment preparation method, which is specifically as follows:

[0056] The sophora fruit is sent to a first steaming and stripping machine for maturation, the maturation temperature is 140℃, the maturation time is 20 min, then the sophora fruit is transferred to a second steaming and stripping machine for fermentation in a closed state by a feeding scraper, the fermentation end point temperature is 59-61℃, the fermentation end point moisture is 13.0-13.5%, after fermentation, the sophora fruit is broken to 30-40 meshes, then the sophora fruit is extracted by 70% ethanol, the extraction temperature is 60℃, the extraction is carried out 5 times under the same condition, the extract is combined and concentrated to 1 / 4.5 of the original volume, then the temperature is reduced for stirring and crystallization, the crystallization time is 5 h, the end point temperature of crystallization is 50℃, rutin and mother liquor are obtained by solid-liquid separation, and the obtained mother liquor is the pigment product.

[0057] Comparative Example 3

[0058] The present comparative example provides a green-yellow pigment, which is prepared by blending sodium copper chlorophyllin, lutein and curcumin according to a mass ratio of 4:2:1.

[0059] Comparative Example 4

[0060] The present comparative example provides a green-yellow pigment, which is prepared by blending sodium copper chlorophyllin and lutein according to a mass ratio of 4:2.

[0061] Comparative Example 5

[0062] The present comparative example provides a green-yellow pigment, which is prepared by blending sodium copper chlorophyllin and curcumin according to a mass ratio of 4:3.

[0063] Pigment index detection of each example and comparative example, and the results are shown in Table 1.

[0064] Pigment index detection of each example and comparative example, and the results are shown in Table 1.

[0065] Table 1

[0066]

[0067] Dyeing performance test of experimental example 2

[0068] 1. Preparation of green-yellow dye

[0069] Dye 1: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Example 1, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0070] Dye 2: 3% copper sulfate is added to the mother liquor obtained in Example 2, and concentrated to a solid content of 67%, and the pH value is adjusted to 5.6.

[0071] Dye 3: 5% potassium dichromate is added to the mother liquor obtained in Example 3, and concentrated to a solid content of 68%, and the pH value is adjusted to 5.8.

[0072] Dye 4: 5% potassium dichromate is added to the mother liquor obtained in Example 3, and concentrated to a solid content of 68%, and the pH value is adjusted to 4.5.

[0073] Dye 5: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Comparative Example 1, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0074] Dye 6: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Comparative Example 2, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0075] Dye 7: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Comparative Example 3, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0076] Dye 8: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Comparative Example 4, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0077] Dye 9: 2% aluminum potassium sulfate dodecahydrate is added to the mother liquor obtained in Comparative Example 5, and concentrated to a solid content of 65%, and the pH value is adjusted to 5.5.

[0078] Dye 10: After the sophora japonica L. is crushed, 10 times water is added and boiled for 30 min to obtain sophora japonica L. pigment, 2% aluminum potassium sulfate dodecahydrate is added, and the solid content is concentrated to 65% and the pH value is adjusted to 5.5.

[0079] Dye 11: After the sophora japonica L. is crushed, 10 times water is added, and the pH value is adjusted to 11.3, and then boiled for 30 min, and then the pH value is adjusted to 6.1 to obtain sophora japonica L. pigment, 2% aluminum potassium sulfate dodecahydrate is added, and the solid content is concentrated to 65% and the pH value is adjusted to 5.5.

[0080] 2. Dyeing method

[0081] The bath ratio is 1:50, the sample to be dyed is put in, and after the temperature reaches 60 DEG C, dyeing is carried out for 60 min, and then taken out, and the water is washed to remove the floating color, and then dried.

[0082] 3. Dyeing performance test

[0083] The pure cotton fabric, cotton / mohair fabric and acrylic fabric are dyed by using the dyes respectively. After the dyeing is completed, the K / S value, the soaping fastness, the rubbing fastness and the light fastness (K / S value is detected by using SF600 colorimeter, and the color fastness detection method refers to the following standards: GB / T 3921-2008 Textile Color Fastness Test Soaping Fastness, GB / T 3920-2008 Textile Color Fastness Test Rubbing Fastness, GB / T 8426-1998 Textile Color Fastness Test Light Fastness: Sunlight) are detected, and the results are shown in the following tables 2-4.

[0084] Table 2 Dyeing performance and fastness of different dyes on pure cotton fabric

[0085]

[0086] Table 3 Dyeing performance and fastness of different dyes on cotton / mohair fabric

[0087]

[0088] Table 4 Dyeing performance and fastness of different dyes on acrylic fabric

[0089]

[0090]

[0091] The above results show that, compared with natural pigments, the green-yellow pigment provided by the application has better dyeing performance and stability, and especially when the pure cotton fabric is dyed, the dyeing performance and fastness are significantly improved.

[0092] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A water-soluble greenish-yellow pigment derived from sophora fruit, characterized in that, It is prepared by the method comprising the following steps: after maturation, the sophora fruit is allowed to rise, then cracking treatment is performed to make the sophora fruit inter-petal cracking, the cracked sophora fruit is mixed with an extraction solvent for extraction, the extract is crystallized, and after solid-liquid separation, rutin and mother liquor are obtained, the mother liquor is water-soluble green-yellow pigment; the water-soluble green-yellow pigment has L value of 78-80, a value of -6.5 to -9.0, and b value of 43.0-44.

5.

2. The water-soluble green-yellow colorant according to claim 1, characterized in that, E of the water-soluble green-yellow pigment 580 1％ 1 cm ≥ 50, insoluble solids ≤ 0.1 %.

3. The method of producing water-soluble green-yellow pigment according to claim 1 or 2, characterized in that, It comprises: After maturation, the sophora fruit is allowed to rise, then cracking treatment is performed to make the sophora fruit inter-petal cracking, the cracked sophora fruit is mixed with an extraction solvent for extraction, the extract is crystallized, and after solid-liquid separation, rutin and mother liquor are obtained, the mother liquor is water-soluble green-yellow pigment.

4. The method for preparing the water-soluble green-yellow pigment according to claim 3, characterized in that, The temperature of the maturation is 90-140℃, and the time is 20-60min; the end point temperature of the rising is 50-70℃.

5. The method for preparing the water-soluble green-yellow pigment according to claim 3, characterized in that, The cracking adopts extrusion type cracking.

6. The method for preparing the water-soluble green-yellow pigment according to claim 3, characterized in that, The extraction solvent is selected from 85%-95% methanol aqueous solution, 70%-80% ethanol aqueous solution, and combinations thereof.

7. The method for preparing the water-soluble green-yellow pigment according to claim 6, characterized in that, The temperature of the extraction is 55-70℃.

8. The method for preparing the water-soluble green-yellow pigment according to claim 3, characterized in that, The extract is concentrated to 1 / 4.5-1 / 7.5 of the original volume before crystallization; The crystallization is cooling and stirring crystallization, the crystallization time is 5-10h, and the end point temperature of the crystallization is 10-50℃.

9. A greenish yellow dye, characterized in that, It comprises a mordant and the water-soluble green-yellow pigment of claim 1 or 2.

10. The greenish yellow dye according to claim 9, characterized in that The mordant is one or more of dichromate, aluminum salt, copper salt, and cobalt salt, and the addition amount is 2-5% of the mass of the water-soluble green-yellow pigment.

11. Process for the preparation of the greenish yellow dye according to claim 9 or 10, characterized in that It comprises: The water-soluble green-yellow pigment is mixed with a mordant, and after concentration, the pH value is adjusted to 5-6.

12. The method of producing a greenish yellow dye according to claim 11, wherein After concentration to total solid content of 65%-70%, the pH value is adjusted to 5-6.

13. Application of the water-soluble green-yellow pigment of claim 1 or 2 or the green-yellow dye of claim 9 or 10 in paper dyeing or cloth dyeing.

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