CN104628734B - A kind of removal methods of microalgae chlorophyll - Google Patents

Abstract

The present invention discloses a kind of removal methods of microalgae chlorophyll.Micro- algae powder or wet algae mud are mixed for 0.5~5.0% according to material concentration (mass volume ratio) with destainer, is reacted 0.5 hour~3.0 hours at 40~70 DEG C, you can removing chlorophyll；The preparation method of described destainer is to mix low-carbon alcohols according to certain volume ratio with the aqueous slkali of concentration 0.5~2.5%.The method of the present invention can be efficient, simple, safe, inexpensive removing microalgae in high content chlorophyll, efficiently solve the chlorophyll pollution problem of microalgae product, and decolouring waste liquid can be used for the preparation of chlorophyll copper sodium, prepared by the extraction that micro- algae powder of dechlorophyllization or wet algae mud can be used for microalgae oil, protein, polysaccharide and carotenoid, Related product can be used for the exploitation of health products, cosmetics, bioenergy, feed, bait etc..

Description

A method for removing chlorophyll from microalgae

Technical field:

The invention belongs to the technical field of chlorophyll removal, and in particular relates to a method for removing chlorophyll from microalgae.

Background technique:

Chlorophyll is an important and indispensable component for microalgae to carry out photosynthesis and maintain normal cell life activities. Usually, the content of chlorophyll in microalgae can account for 0.2-2.0% of the dry weight of cells. Chlorophyll is a magnesium porphyrin compound with a high color value (greater than 500). It can appear green in a small amount. The presence of chlorophyll seriously affects the quality of microalgae end products (such as oil, protein, polysaccharides and carotenoids). The patent provides an efficient, simple, low-cost and safe process for removing chlorophyll from microalgae, which effectively solves the problem of chlorophyll pollution of microalgae products. The shortcoming of prior art and purpose of the present invention are detailed as follows:

1. "Using chlorophyll hydrolase to decompose chlorophyll", it is first necessary to extract microalgae chlorophyll, and then add enzymes to decompose chlorophyll. The cost of this method is relatively high and the decolorization efficiency is low; 2, "use organic solvent to remove chlorophyll in microalgae", usually choose organic solvents such as acetone to repeatedly extract algae powder or wet algae mud, the above-mentioned solvent has certain toxicity, If the follow-up treatment is not thorough, it will have a certain impact on the safety of algae powder or wet algae mud. At the same time, in the process of organic solvent extraction of chlorophyll, most of the high-value chemical components will be lost, such as carotenoids, microalgae oil, etc. The chlorophyll in the liquid is unstable and easy to decompose; 3. Unrefined microalgae oil usually contains high concentrations of chlorophyll, and the existence of these chlorophylls has a very adverse effect on the comprehensive utilization of microalgae oil, such as the use of microalgae oil Preparation of biodiesel, microalgae oil processing health products and food, etc. Studies have shown that: the use of traditional oil decolorization process (such as hydrogen peroxide, activated carbon, diatomaceous earth and other oxidative adsorption) has no obvious decolorization effect on microalgae oil containing chlorophyll; Not easy to obtain; 5. Algae powder or algae mud contains a certain amount of chlorophyll. When making chewable tablets, the mouth of the eater will often be stained with an ugly green color, which will affect the quality of the product to a certain extent.

Chlorophyll (chlorophyll) is a kind of pigment related to photosynthesis, which is widely present in all photoautotrophic growth organisms (such as prokaryotic algae, green plants, eukaryotic algae, etc.), and it is combined with the cell light-harvesting pigment protein complex It exists on the photosynthetic membrane and is responsible for the absorption and transmission of light energy. Chlorophyll is a magnesium porphyrin compound, its molecule contains a "head" of a porphyrin ring and a "tail" of phytol, and the magnesium atom is located in the center of the porphyrin ring (as shown in Figure 1). Chlorophyll can absorb most of the red light and purple light and reflect green light, so it appears green. Chlorophyll is insoluble in water, but soluble in various organic solvents, such as ethanol, acetone, ether, chloroform, etc. Chlorophyll is the ester of chlorophyllin, which can undergo saponification reaction. There are many types of chlorophyll, including chlorophyll a, b, c, d, f and bacteriochlorophyll, among them, chlorophyll a (C ₅₅ H ₇₂ O ₅ N ₄ Mg) and chlorophyll b (C ₅₅ H ₇₀ O ₆ N ₄ Mg ) is the most common, chlorophyll a is green, and chlorophyll b is yellow-green. Chlorophyll is unstable, and light, acid, alkali, oxygen, and oxidants will decompose it. Under acidic conditions, chlorophyll easily loses magnesium atoms and becomes magnesium chlorophyll, which is dark brown. Magnesium ions in chlorophyll a and b molecules are easily replaced by copper, iron, cobalt and other ions to form chlorophyll derivatives. Chlorophyll derivatives can be used to make catalysts, photosensitizers, food pigments, paints, etc., the most important of which is water-soluble copper chlorophyll Sodium salt (Figure 2), which can treat diseases such as infectious hepatitis, stomach, pancreatitis, duodenal ulcer, chronic nephritis and leukemia, copper chlorophyllin sodium salt has been widely used, and is currently the main raw material for preparing copper chlorophyllin sodium salt For silkworm excrement.

Although chlorophyll has important biological activities and can be used alone as food additives, medicines, and health products, when it exists in other microalgae products (microalgae oil, protein, polysaccharides and carotenoids), it will seriously reduce microalgae. The quality of algae products (color, purity, etc.). For example: 1) Microalgae oil containing long-chain polyunsaturated fatty acids is a high-grade health care product and cosmetic raw material. After extracting this type of microalgae oil, it is found that its color is usually dark green, brown or black. After research It is proved that the above-mentioned color is mainly derived from chlorophyll, and the traditional decolorization process (such as hydrogen peroxide, activated carbon, diatomaceous earth and other oxidation adsorption) cannot effectively remove the color; 2), at present, "algae tablet" has been widely accepted as a health product , but when people eat algae tablets (especially chewable tablets), the existence of chlorophyll will seriously affect the taste of users. Chlorophyll exists in the mouth and produces ugly colors. This is also one of the reasons why microalgae chewable tablets are difficult to widely promote; 3) Using microalgae oil to prepare biodiesel, chlorophyll, as a fat-soluble substance, is usually extracted together with microalgae oil. During the process of transesterification of microalgae oil to generate fatty acid methyl ester, chlorophyll also undergoes methylation reaction. It produces methyl chlorophyllate with an ugly color, which is mixed in biodiesel and affects the performance of biodiesel (cetane number, saponification value, iodine value, freezing point and long-chain saturation factor, etc.), resulting in the inability of microalgae biodiesel to achieve standard.

How to effectively remove chlorophyll from microalgae cells, so that microalgae biomass or finely processed products of microalgae are more easily accepted by the public. At present, some related technical inventions have been announced at home and abroad, but these technologies cannot be well promoted and developed. For use, the following examples are given to describe the disclosed representative technical inventions:

(1), the method for removing chlorophyll in vegetable oil and its special device (patent application number: CN201410049242.X), it has been proved by research that there is no obvious decolorization effect by using the technology of this invention to process the microalgae oil containing chlorophyll; (2), using A method for removing chlorophyll, color bodies and phospholipids from glyceride oil by acid-treated silica adsorbent (patent application number: CN91109410.5). It has been proved by research that microalgae oil is treated with silica adsorbent in this patent without obvious Decolorization effect; (3), composition and method for enzymatic decolorization of chlorophyll (patent application number: CN201310031421.6), the cost of this technology is relatively high, and it is still in the stage of laboratory exploration, and the raw material processed at the same time is chlorophyll (4), a method for preparing moderately processed ARA microalgae oil (patent application number: CN201310254172.7), which has a higher chlorophyll content (5), a kind of decolorization column and the normal temperature decolorization method (patent application number: CN201010227935.5) that utilizes DHA oil and fat of a kind of decolorization column, but this technology enlarges cost relatively high, it is difficult to carry out large-scale application, and at the same time, this technology cannot handle algae powder or wet algae mud with higher chlorophyll content; (6), a method for continuous extraction of functional components of chlorella (patent application number: CN200910220586.1 ), the invention uses organic solvents to extract chlorophyll, if the follow-up treatment is not thorough, it will have a certain impact on the safety of algal powder, and at the same time, in the process of extracting chlorophyll with organic solvents, a part of valuable chemical components will be lost; (7) 1. One-step preparation of bioenergy by microalgae (patent application number: CN200910148494.7). This technology requires precise control of reaction conditions to avoid transesterification of chlorophyll, so it is difficult for this invention to be scaled up on a large scale.

Through the analysis of existing inventions, it is found that most of the decolorization technologies that have been disclosed have deficiencies. On the one hand, there is a lack of chlorophyll removal technology specifically for microalgae algae powder or wet algae mud. On the other hand, most patents cannot be promoted well. and use.

The methods currently used for chlorophyll removal mainly include: high-temperature phosphoric acid method (using oil as raw material), organic solvent extraction method (using algae powder or algae mud as raw material), enzymatic decolorization method (using chlorophyll extract as raw material), silica Adsorption method (with grease as raw material) etc., the shortcoming of prior art is detailed as follows:

(1), high-temperature phosphoric acid method and silica adsorption method: all are to remove the pigment mixed wherein on the basis of grease, although above-mentioned two kinds of methods all have better decolorization effect to vegetable fat, animal fat, waste oil, but Microalgae cells usually contain more chlorophyll, and it is difficult to achieve an effective decolorization effect by using the above two methods; (2), enzymatic decolorization method: chlorophyll hydrolase can decompose chlorophyll efficiently and gently to achieve degreening of microalgae , there are three problems in the enzymatic degreening method: first, chlorophyll hydrolase cannot enter the cell to play a role, so this technology cannot be used to treat algae powder or wet algal mud; second, this technology first needs to extract chlorophyll, and then add chlorophyll Hydrolase, but when chlorophyll hydrolase is placed in an organic solvent, it will be partially or completely inactivated. If the organic solvent is volatilized and then treated with hydrolase, it will consume a lot of cost. Third, this technology is still in the laboratory stage. Whether the decomposition efficiency of chlorophyll after amplification can meet the degreening requirements; (3), organic solvent extraction method: acetone and other organic solvents repeatedly extract chlorophyll, which is energy-consuming, time-consuming and inefficient, and the follow-up treatment of organic solvents is not thorough Will have a certain impact on the safety of algae powder; (4), chlorophyll is a kind of bioactive substance with high development value, only considers that chlorophyll is removed in all above-mentioned processes, does not consider that chlorophyll is reclaimed, therefore, There is waste of high value bioactive ingredients.

Invention content:

The first object of the present invention is to provide a method for removing chlorophyll from microalgae based on saponification reaction. The method of the present invention can remove high-content chlorophyll in microalgae with high efficiency, simplicity, safety and low cost, effectively solves the problem of chlorophyll pollution of microalgae products, and the decolorization waste liquid can be used for the preparation of sodium copper chlorophyllin, degreening microalgae Algae powder or wet algae mud can be used for the extraction and preparation of microalgae oil, protein, polysaccharides and carotenoids, and can also be used for the development of health care products, cosmetics, bio-energy, feed, bait, etc.

The second object of the present invention is to provide the application of the decolorization waste liquid obtained by the microalgae chlorophyll removal method described in claim 1 in the preparation of sodium copper chlorophyllin.

The third object of the present invention is to provide the application of degreening microalgae powder or wet algae mud obtained by the microalgae chlorophyll removal method described in claim 1 in extracting and preparing microalgae oil, protein, polysaccharide and carotenoid .

The removal method of microalgae chlorophyll of the present invention is characterized in that, comprises the following steps:

Mix the microalgae powder or wet algae mud with the decolorization solution according to the material concentration (mass volume ratio) of 0.5-5.0%, and react at 40-70°C for 0.5-3.0 hours to remove chlorophyll; the decolorization The preparation method of the liquid is that the low-carbon alcohol and the alkali solution with a concentration of 0.5-2.5% are mixed according to a certain volume ratio.

The low-carbon alcohol is preferably methanol or ethanol with a concentration of 100%. Usually, safe ethanol is used as the component of the decolorization solution. Ethanol has been widely used in food, medicine and other fields, and has relatively high safety, while methanol is toxic. If it is not treated thoroughly, it will affect the quality of the dechlorination algae powder. If the degreening microalgae powder or wet algal mud in the present invention is used in non-edible fields (such as the preparation of biodiesel oil), methanol can be used as the decolorizing solution component, otherwise ethanol can be used as the decolorizing solution component.

The alkaline solution is preferably sodium hydroxide (NaOH) or potassium hydroxide (KOH) solution. The two can achieve the same decolorization effect, but combined with the subsequent preparation process of "sodium copper chlorophyllin", sodium hydroxide is more suitable, because the introduction of potassium ions will increase the cost of subsequent potassium ion removal. Excessively high alkali concentration will increase the decolorization efficiency, but will significantly reduce the retention rate of oil, protein, and polysaccharides. Excessively high alcohol concentration can leach other components in microalgae (such as microalgae oil, protein or carbohydrates), reducing algae. powder value.

Preferably, the volume ratio of the low-carbon alcohol to the alkali solution is 1:4-10. Chlorophyll can undergo saponification reaction in the presence of alkali (as shown in Figure 2), and generate water-soluble chlorophyll salt and phytol. When a small amount of low-carbon alcohol is added to the reaction system, the ability of hydroxide to enter the cell can be improved , to increase the efficiency of the saponification reaction.

The microalgae are preferably green algae, diatoms, euphratica, and cyanobacteria.

The reaction temperature is one of the main factors affecting the decolorization efficiency. Increasing the temperature can shorten the decolorization time and improve the decolorization effect, but increasing the temperature will reduce the retention rate of microalgae oil, protein and carbohydrates and increase energy consumption. Therefore, in the present invention The reaction temperature is 40～70℃.

The material concentration is affected by the chlorophyll content in the material. When the chlorophyll concentration in the microalgae powder or wet algae mud is high, a lower material concentration is usually selected, and when the chlorophyll concentration is low, the material concentration can be increased appropriately. The material concentration will increase the cost of decolorization, and too high material concentration will reduce the decolorization efficiency. The material concentration provided by the invention is in the range of 0.5-5.0%.

Prolonging the reaction time will improve the decolorization efficiency, but it will reduce the retention rate of microalgae oil, protein and polysaccharide in microalgae powder or wet algae mud, and increase the energy consumption of the reaction. Based on the difference in chlorophyll concentration in the material, the reaction provided by the invention The time is between 0.5 hours and 3 hours.

The microalgae chlorophyll removal process provided by the present invention is based on the principle of saponification, and uses the alcohol-alkali mixed solution to directly process the algae powder or wet algae mud containing chlorophyll, so as to realize the synchronization of chlorophyll extraction and saponification, improve the decolorization efficiency, simplify the process, and reduce the cost At the same time, the decolorization solution containing sodium magnesium chlorophyllin can be used for the preparation of sodium copper chlorophyllin, so as to realize the recycling of waste liquid. The present invention uses highly safe alcohol-alkali mixed solution to treat algae powder or wet algae mud containing chlorophyll. The destructive effect of the active ingredient is less and the decolorizing solution has high safety. In addition, after chlorophyll is transformed into magnesium chlorophyllin sodium salt through saponification, its stability increases, which is beneficial to the subsequent preparation of commercial copper chlorophyllin sodium copper chlorophyllin. The present invention avoids the removal of chlorophyll on the basis of oil, but by performing chlorophyll removal treatment on oil-containing algae powder or wet algae mud, the oil in oil-containing algae powder or wet algae mud is retained, and the chlorophyll-free oil-containing algae powder is then processed into oil Extraction, thereby indirectly solving the decolorization problem of microalgae oil. The present invention can utilize the decolorization liquid containing magnesium sodium chlorophyllin of microalgae to prepare sodium copper chlorophyllin, so as to realize the recovery and utilization of waste liquid. The invention can effectively remove the chlorophyll in the algae powder or the algae mud, and when the chlorophyll-free algae powder is used to make algae tablets or health-care capsules, the grade of the product will be greatly improved.

Description of drawings:

Figure 1 is the structure of chlorophyll, wherein, A: chlorophyll a; B: chlorophyll b;

Fig. 2 is the saponification reaction of chlorophyll;

Figure 3 is a flow chart of the chlorophyll removal process.

detailed description:

The following examples are to further illustrate the present invention, rather than limit the present invention.

The methods used in the examples of the present invention are conventional methods unless otherwise specified.

Example 1:

A kind of green algae was selected to study the chlorophyll removal process. Through measurement, it is found that the chlorophyll content of the algae powder is 0.48g/100g-1.20g/100g, the algae powder before decolorization is yellow-green or green, and the algae oil is dark brown or black. Optimal decolorization conditions were obtained through process parameter optimization: the decolorization solution was obtained by mixing 100% ethanol with 1% to 2% sodium hydroxide solution according to the volume ratio of 1:4, and then the green algae powder According to the material concentration of 1% to 2%, it is mixed with the decolorizing solution and reacted at 70° C. for 1.0 to 2.0 hours to remove the chlorophyll from the algae powder.

By the method of this embodiment, the removal rate of chlorophyll is more than 90%, the algae powder after decolorization becomes orange-red or gray-yellow, the extracted microalgae oil is transparent orange-red or slightly yellow, and the neutrality of microalgae oil is The proportion of lipids increased, the proportion of membrane lipids (glycolipids and phospholipids) decreased, and the composition of fatty acids remained unchanged.

The decolorized waste liquid in this example can be used for the preparation of sodium copper chlorophyllin, the chlorophyllized green algae powder can be used for the extraction and preparation of microalgae oil, protein, polysaccharide and carotenoid, and the chlorophyllized green algae powder can be used for health care Development of products, cosmetics, bio-energy, feed, bait, etc.

Example 2:

A diatom was chosen to study the chlorophyll removal process. It is found by measuring that the chlorophyll content of the algae powder is 0.32g/100g, and the algae powder before decolorization is dark brown. Mix ethanol with a concentration of 100% and a sodium hydroxide solution with a concentration of 0.5% according to a volume ratio of 1:10 or 1:5 to obtain a decolorizing solution, and then diatom algae powder is mixed with the decolorizing solution according to a material concentration of 0.5%. React at 40°C for 3.0 hours to remove chlorophyll from the algae powder.

Through the method of this embodiment, the removal rate of chlorophyll can reach more than 90%.

The decolorized waste liquid in this example can be used for the preparation of sodium copper chlorophyllin, the diatom powder of chlorophyll can be used for the extraction and preparation of microalgae oil, protein, polysaccharide and carotenoid, and the diatom powder of chlorophyll can be used for Development of health products, cosmetics, bio-energy, feed, bait, etc.

Example 3:

A species of Eurythmia euphratus was chosen to study the chlorophyll removal process. The algae powder before decolorization is green or yellow-green, and the algae oil is dark brown. Mix ethanol with a concentration of 100% and potassium hydroxide solution with a concentration of 2% according to the volume ratio of 1:4 to obtain a decolorizing solution, and then mix the algae powder with the decolorizing solution according to the material concentration of 1% to 5%. , react at 70°C for 1 to 2 hours to remove chlorophyll from the algae powder.

By the method of this embodiment, the removal rate of chlorophyll can exceed 95%, the algae flour after degreening becomes pale yellow or orange, the microalgae oil becomes yellow or transparent orange, and the neutral lipid ratio of microalgae oil increases , the ratio of glycolipids and phospholipids is reduced.

The decolorization waste liquid in this example can be used for the preparation of sodium copper chlorophyllin, and the chlorophyllous Euophthalma algae powder can be used for the extraction and preparation of microalgae oil, protein, polysaccharide and carotenoids, and the chlorophyllous Euophthalma algae Powder can be used in the development of health products, cosmetics, bio-energy, feed, bait, etc.

Example 4:

A cyanobacteria was selected to study the chlorophyll removal process. It is found through measurement that the chlorophyll content of the algae powder is 0.54g/100g-0.80g/100g. Mix ethanol with a concentration of 100% and a sodium hydroxide solution with a concentration of 2% according to the volume ratio of 1:4 to obtain a decolorizing solution, and then mix the cyanobacteria powder with the decolorizing solution according to a material concentration of 2%, and react at 70°C After 1.5 hours, the algae powder can be removed from chlorophyll.

Through the method of this embodiment, the removal rate of chlorophyll of blue-green algae can reach more than 95%.

The decolorized waste liquid in this example can be used for the preparation of sodium copper chlorophyllin, the cyanobacteria powder of chlorophyll can be used for the extraction and preparation of microalgae oil, protein, polysaccharide and carotenoid, and the cyanobacteria powder of chlorophyll can be used for health products, Development of cosmetics, bio-energy, feed, bait, etc.

Example 5:

A green algae wet algae mud was selected to study the chlorophyll removal process. The wet algae mud before decolorization is green. Mix methanol with a concentration of 100% and a sodium hydroxide solution with a concentration of 2.5% according to a volume ratio of 1:4 to obtain a decolorizing solution, and then mix the green algae wet algae mud with the decolorizing solution according to a material concentration of 2%, and heat it at 70°C After 0.5-1.5 hours of reaction, the wet algae mud can be removed from chlorophyll.

Through the method of this embodiment, the chlorophyll removal rate of the green algae wet algae mud reaches more than 90%, and the dechlorination algae powder turns grayish yellow. The extracted microalgae oil is slightly yellow, the proportion of neutral lipids in the microalgae oil is increased, and the composition of fatty acids remains unchanged.

Since methanol is used as a component of the decolorizing solution, the green algae wet algae mud in this example is used for the preparation of biodiesel oil. The decolorized waste liquid in this example can be used for the preparation of sodium copper chlorophyllin.

In summary, through the analysis of the biochemical composition of the chlorophyll-removed algae powder and wet algae mud with a removal rate of more than 90%, it is found that compared with the original algae powder and wet algae mud without chlorophyll, the algae powder and wet algae with chlorophyll The total fat content of the mud is reduced by 8.2-12.2%, the carbohydrate content is reduced by 9.1-11.3%, and the protein content is reduced by 12.3-25.2%.

Claims (3)

1. a method for removing microalgae chlorophyll, is characterized in that, comprises the following steps: Mix the microalgae powder or wet algae mud with the decolorization solution according to the material concentration of 0.5-5.0%, and react at 40-70°C for 0.5-3.0 hours to remove chlorophyll; the preparation method of the decolorization solution is as follows: It is prepared by mixing low-carbon alcohol with a concentration of 100% and an alkali solution with a concentration of 0.5-2.5% at a volume ratio of 1:4-10, and the low-carbon alcohol is methanol or ethanol. 2. The method for removing chlorophyll from microalgae according to claim 1, wherein the alkaline solution is sodium hydroxide or potassium hydroxide solution. 3. the removal method of microalgae chlorophyll according to claim 1, is characterized in that, described microalgae is green algae, diatom, eutectic algae and blue-green algae.