CN103773596B - The preparation method of krill oil - Google Patents

Abstract

The invention discloses a preparation method of krill oil, which comprises the following steps: (1) uniformly mixing krill with an extractant, and shearing; the amount of the extractant added is 1L of extractant; (2) solid-liquid separation to obtain shrimp paste; (3) mix shrimp paste and extractant evenly, extract to obtain extract, and remove solvent; the amount of extractant added is 1 kg of krill -2L extractant; the extractant is a C _2-4 alcohol or an aqueous solution of a C _2-4 alcohol. The preparation method does not need to go through the existing conventional dehydration process, the preparation method is simple, the prepared krill has good fluidity, high transparency, less water-soluble impurities, the phospholipid content is more than 40%, and the lecithin content in the phospholipid is more than 60%.

Description

Preparation method of krill oil

technical field

The invention relates to a preparation method of krill oil.

Background technique

Antarctic krill is a species of krill that lives in the waters of Antarctica and is one of the largest and most mature single-species biological resources on Earth. Krill oil extracted from Antarctic krill is rich in phospholipids (mainly lecithin) and other components, and the fatty acids of phospholipids mainly include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) , the sum of the content of the two accounts for more than 40% of the total amount of fatty acids in phospholipids. Antarctic krill oil has various physiological activities such as reducing cardiovascular disease, preventing senile dementia and improving body immunity, and its activity is superior to triglyceride-type EPA/DHA products and terrestrial plant-derived lecithin products currently on the market (EPA and DHA are not included in its fatty acid composition).

The unsaturated fatty acid docosahexaenoic acid (DHA) is mainly combined on the 2-position (Sn2 position) of the glycerol group of the phospholipid. DHA is the basis of the brain cell membrane, and it plays an important role in the division, proliferation, nerve conduction and synapse of brain cells. It plays an extremely important role in the growth and development of the human brain and is an essential substance for the formation of the human brain and the development of IQ. Moreover, DHA has a great impact on vision, brain activity, fat metabolism, fetal growth, immune function and prevention of senile dementia. When DHA is deficient, it can cause a series of symptoms, including growth retardation, abnormal skin scales, infertility, mental retardation, etc.

However, ordinary DHA is arranged in a random manner and is in a state of disorder, so it cannot be guaranteed to be completely absorbed by the human body. Usually, the DHA at the Sn1 and Sn3 positions are digested in the human body and generate heat. Only the DHA at the Sn2 position can be absorbed by the human body. Absorbs completely. DHA in krill oil is bound to the Sn2 position of the glycerol group of phospholipids, so it can be completely absorbed by humans. The biological activity and bioavailability of DHA on the Sn2 position of krill are very high, which is 3-3 times the activity of DHA in ordinary fish oil. 5 times.

At the same time, krill oil can be converted into phosphatidylserine (PS) through the method of biological enzyme catalysis. The function of phosphatidylserine (PS) is mainly to improve the function of nerve cells, regulate the conduction of nerve impulses, and enhance the memory function of the brain. Relevant experts agree that the unsaturated fatty acid docosahexaene (DHA) derived from krill oil is bound to phosphatidylserine (PS). The combined effect of the two can improve the function of brain nerve cells and brain activity, and improve memory It is of great economic and theoretical value to promote brain development and maintain brain health in infants and young children.

Based on the important status of Antarctic krill resources, all countries in the world regard Antarctic krill as an important food resource, and began to hunt for Antarctic krill in the early 1960s. Since its production, the total catch of Antarctic krill has exceeded 6 million tons. But at present, most of the Antarctic krill caught in the world are processed into feed for aquaculture, and its economic value and social value are far from being fully reflected. Under the realistic background of sharply rising energy prices and labor costs, making full use of krill oil resources in Antarctic krill and developing high value-added products is an important way to utilize Antarctic krill.

After entering the 21st century, the market demand for pharmaceutical-grade krill oil has grown rapidly, and the krill industry has seized this opportunity. Due to its rich phospholipids, krill oil has attracted great attention from the nutraceutical industry. At the same time, the rapid development of the krill health products market has formed an increasingly fierce market competition with other marine life health products. Norway's AkerBiomarine and Canada's Neptune Technologies are currently the world's major producers of pharmaceutical grade krill oil. In particular, AkerBiomarine, a Norwegian seafood fishing and processing company, has been engaged in the R&D, production and sales of high-end krill products for many years. In 2009 alone, the company sold about 100 tons of krill oil health products.

Recently, there are more and more domestic units engaged in research and development and production of krill oil. The previous extraction method of krill oil is extraction by heating and pressing, but this method has low yield and high operating temperature, which has an impact on product quality and has been gradually eliminated. In the prior art, dry krill powder (water content 8%-10%) is generally used as raw material to extract krill oil by solvent method, but this method also has certain defects. First, krill powder has a certain impact on water content. Strict requirements, generally require a water content of 8%-10%, because too high a water content will have a great impact on the extraction rate, and will also cause a large amount of harmful water-soluble impurities to enter the extract, increasing post-treatment purification Difficulty in the process; second, Antarctic krill contains an enzyme that, after being caught, will quickly enzymolyze the protein in krill within a few hours at normal temperature and turn it into a toxic substance, commonly known as krill autolysis, after autolysis The krill in the krill cannot be eaten by humans, so the preparation of krill powder is generally carried out on the fishing boat, but the space of the fishing boat is small and the processing capacity is limited. In addition, the market demand for krill powder is large, so the supply of krill powder is in short supply. Phenomenon, expensive.

On the other hand, on the fishing boat, krill can also be quickly frozen to below -20°C, and stored and transported in the form of frozen shrimp. In the prior art, people also try to directly extract krill oil from frozen shrimp. The extraction method is generally to remove the water first, and then extract the krill oil. The method of removing moisture generally adopts low-temperature freeze-drying method to dehydrate. This method has low operating temperature (below -30 degrees), long dehydration time and high cost. Another dehydration method is heating and dehydration under vacuum. This method consumes a lot of energy, and because phospholipids in krill oil are heat-sensitive substances, they will be decomposed in large quantities when the temperature is high, so that the dehydration temperature cannot be too high, so that the dehydration time becomes very long. It generally takes 7-8 hours and is not suitable for large-scale industrial production.

Moreover, after the krill oil is extracted, processes such as refining are required to remove impurities in the krill oil. In a word, the krill oil extraction method in the prior art has complex extraction process steps and high components. This phenomenon increases the composition of phospholipids, which needs to be solved urgently. Therefore, it is very urgent to develop a method that directly uses frozen Antarctic krill as raw material, has a simple preparation process, and consumes less time and energy to extract krill oil.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the large demand for krill powder and insufficient supply of raw materials in the prior art method of extracting krill oil with krill powder as raw material, and to use frozen krill as raw material to extract krill oil to prepare The time is long and the defects of high energy consumption provide a preparation method of krill oil. The preparation method does not need to go through the existing conventional dehydration process, the preparation method is simple, and the prepared krill oil has good fluidity and transparency. High, less water-soluble impurities (such as polysaccharides, low-molecular-weight polypeptides, etc.), the extraction rate is significantly improved, the content of phospholipids is more than 40%, and the content of lecithin in phospholipids is more than 60%.

Among the extraction methods of krill oil in the prior art, the dehydration method of krill takes a long time and has high cost. On this basis, the inventors removed water by adding a specific concentration of extractant to krill. However, a large number of experiments have shown that the removal of water from krill by extractants is not as easy as imagined. In a large number of experiments, the extraction rate of krill oil is almost 0, that is to say: krill oil cannot be extracted at all with simple extractants. The reason is: ethanol can extract water and phospholipids at the same time, but the present invention needs to separate water and phospholipids to obtain the target extract—phospholipids, and when the water cannot be removed first, phospholipids cannot be extracted. This is also the reason why _C2-4 alcohols have not been used to remove moisture in krill in the prior art.

However, after further research, the inventors have found that: a specific amount of extractant, combined with specific process steps and conditions, not only can remove the moisture in krill, but will not cause the loss of phospholipids. On this basis, it can also Impurities in krill oil are removed, so that high-purity krill oil can be obtained without the need for a refining process, and the extraction rate of krill oil is also improved, achieving the effect of killing multiple birds with one stone. So far, just obtained technical scheme of the present invention.

The object of the present invention is to: provide a kind of preparation method of krill oil, described preparation method comprises the following steps:

(1) Mix krill and extractant evenly to obtain mixture A, and cut; the extractant is C _2-4 alcohol or an aqueous solution of C _2-4 alcohol, and the amount of the extractant added is Add 1L of extractant per 0.5-1.5kg of krill;

(2) Solid-liquid separation to obtain shrimp paste;

(3) Mix the shrimp paste with the extractant evenly to obtain the mixture B, extract to obtain the extract, and remove the solvent; the extractant is C _2-4 alcohol or C _2-4 Alcohol aqueous solution, the amount of the extractant added is 1-2L of extractant per 1kg of krill.

The following is a further description for the above-mentioned preparation method:

In step (1), before mixing the krill and the extract evenly, it is preferable to perform a certain pretreatment on the krill; the pretreatment method is a conventional method in the field, such as washing Clean, drain, etc. The method of draining is a conventional method in the art, preferably natural draining.

Those skilled in the art all understand that: because krill autolyzes rapidly at room temperature, the quality changes rapidly, generally speaking, frozen storage is required; when the krill is frozen krill, krill preferably needs to be thawed , then drain. The method of thawing is a conventional method in the art, preferably mixing the frozen krill with water evenly at 10-20° C., and then soaking. The time for thawing is conventional in the field, preferably within 30 minutes; the amount of water used is conventional in the field, preferably submerging the frozen krill. Soaking thawing is better than thawing krill naturally in the air or heating it. After the thawing, the krill is preferably washed and then drained. Generally speaking, the process from thawing to draining can remove a large amount of water-soluble impurities on the surface of krill, such as NaCl, thereby reducing the impurity content in the final product.

In the present invention, the alcohol is preferably a C _2-3 alcohol, more preferably one or more of ethanol, n-propanol and isopropanol.

In step (1), the amount of the extractant added is preferably 1 L of extractant per 1 kg of krill.

In step (1), after the mixing is uniform, the alcohol content in the mixture A is preferably 40%-80%, more preferably 50%-70%; the percentage is the Alcohol accounts for the volume percentage of the liquid in the mixture A.

In step (1), when the krill is mixed evenly, the krill is fully contacted with the extractant, a large amount of water in the krill is released, and the concentration of the extractant is further reduced. At this concentration, the krill oil will not be leached, and the impurities in the shrimp (such as polysaccharides, low molecular weight peptides, etc.) can be leached. This step not only removes the water in the krill, but also lays the foundation for the subsequent extraction of krill, and at the same time removes the impurities in the krill, so that the tedious and time-consuming refining process is unnecessary after the krill oil is extracted.

In step (1), the concentration of the alcohol aqueous solution is preferably above 90%, more preferably 95%, and the percentage is the volume percentage of the alcohol in the alcohol aqueous solution.

In step (1), preferably, before the shearing, the krill and the extractant are stirred and preliminarily crushed. The crushing method is preferably to use a gear pump for crushing.

In step (1), preferably, the shearing method and conditions are conventional methods and conditions in the art. The shearing speed is preferably 5000-12000 rpm, more preferably 10000 rpm. The shearing time is preferably 5-15 minutes, more preferably 10 minutes. The shearing is preferably carried out in a high-speed shear.

In step (2), the method and conditions for solid-liquid separation are conventional methods and conditions in the art. The method of solid-liquid separation is preferably centrifugal separation; the separation factor (ratio of centrifugal force and gravity) of the centrifuge is preferably greater than 2500G, more preferably 2500-3000G. The residence time of the centrifugal separation is preferably 10-20min, more preferably 15min. The centrifugation is preferably centrifuged using a tabletop centrifuge or a decanter centrifuge.

In step (2), preferably, the alcohol-containing liquid substance obtained by the solid-liquid separation can be recovered according to the conventional alcohol recovery method in the art; the recovery method is preferably distillation; the Said distillation is preferably carried out using tower equipment under normal pressure.

In step (3), the amount of the extractant added is preferably 1 L of extractant per 1 kg of krill.

In step (3), after the mixing is uniform, the alcohol content in the mixture B is preferably 90%-95%, and the percentage is that the alcohol accounts for the liquid in the mixture B volume percentage.

In step (3), the extraction is preferably stirring extraction. The extraction time is preferably 20-40 minutes, more preferably 30 minutes.

In step (3), preferably, the number of extractions is conventional in the art, and the number of extractions is preferably 2-3 times. When the number of extractions is more than one, the extracts are combined according to the routine in this field.

In step (3), the method and conditions for removing the solvent are conventional methods and conditions in the art; the method for removing the solvent is preferably vacuum removal of the solvent at a temperature below 60°C. The temperature for removing the solvent is preferably 40-55°C. The time for removing the solvent is preferably 10-30 min. The solvent removal is preferably carried out sequentially in a water ring vacuum pump and a plate mechanical vacuum pump, or in a rotary plate evaporator.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The reagents and raw materials used in the present invention are all commercially available.

The positive and progressive effects of the present invention are: the krill oil extraction method of the present invention has a simple preparation method, and the prepared krill oil has good fluidity, high transparency, less water-soluble impurities (such as polysaccharides, low-molecular polypeptides, etc.), and is easy to extract. The rate is obviously improved, the phospholipid content is more than 40%, and the lecithin content in the phospholipid is more than 60%.

detailed description

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples. For the experimental methods that do not specify specific conditions in the following examples, select according to conventional methods and conditions, or according to the product instructions.

Example 1

(1) Still water thawing: take 190g frozen Antarctic krill, add it to a water-containing container, soak in still water at a water temperature of 18°C for 15 minutes, the frozen shrimp will melt, and the water temperature will drop to about 12°C at this time; drain the water with a funnel , if necessary, rinse with a small amount of pure water at 4-6°C to remove the entrained NaCl;

(2) Mix 200mL of 95% ethanol with the drained shrimp body to obtain a mixed solution A, the content of ethanol in the mixed solution A is 60% (the volume percentage of ethanol in the liquid in the mixture A), crush it, and add it to the high The shearing machine cuts at 10000rpm for 10min;

(3) Use a desktop centrifuge to centrifuge at 3000G for 15 minutes to obtain shrimp paste;

(4) Add 200mL of 95% ethanol to the shrimp paste and mix evenly to obtain a mixture B. The content of ethanol in the mixture B is 90% (the volume percentage of ethanol in the liquid in the mixture B), stir for 30min, and separate into layers. Filter off the ethanol phase; add 200mL of absolute ethanol, repeat the extraction, and combine the secondary extracts; at 60°C, in a glass rotary evaporator, vacuumize with a water ring vacuum pump to remove ethanol, and then use a plate-encapsulating machine to evacuate the ethanol phase. Vacuum pump, under high vacuum conditions, continue to remove residual ethanol and trace moisture (10 minutes).

The obtained product is dark reddish brown and is flowable. The product can be filled with capsules, and the content of the capsules is not cloudy, indicating that the prepared product is transparent and in good condition.

The content of phospholipids in krill oil products measured by molybdenum blue colorimetry is 41%, and the content of lecithin in phospholipids is 70%.

Example 2

(1) Still water thawing: Take 400g frozen Antarctic krill, add it to a water-containing container, soak in still water for 15 minutes at a water temperature of 20°C, and the frozen shrimp will melt; drain the water with a funnel, and use a small amount of 4-6°C if necessary rinse with pure water;

(2) Add 500mL of isopropanol to the above-mentioned thawed and drained shrimp body, and mix thoroughly to obtain a mixture A, the content of isopropanol in the mixture A is 70% (isopropanol accounts for the liquid in the mixture A % by volume), pulverized, and added to a high shear machine to shear at 10000rpm for 10min;

(3) Use a desktop centrifuge to centrifuge at 3000G for 15 minutes to obtain shrimp paste;

(4) Add 500mL of isopropanol to the shrimp paste and mix evenly to obtain mixture B. The content of isopropanol in mixture B is 90% (the volume percentage of isopropanol in the liquid in mixture B), stir for 30min, Static layering, filter the isopropanol phase; add 500mL of isopropanol, repeat the extraction, combine the secondary extracts, and remove the isopropanol in a glass rotary evaporator at 60°C with a water ring vacuum pump , and then use the mechanical vacuum pump to evacuate, and continue to remove residual isopropanol and trace moisture (15min) under high vacuum conditions.

The obtained product is dark reddish brown and is flowable. The product can be filled with capsules, and the content of the capsules is not cloudy, indicating that the prepared product is transparent and in good condition.

The content of phospholipids in krill oil products measured by molybdenum blue colorimetry is 43%, and the content of lecithin in phospholipids is 65%.

Example 3

(1) Static water thawing: Take 500 kg of frozen Antarctic krill, add it to a 1500-liter stainless steel extraction tank, fill up with water, and thaw it at a water temperature of 15°C for 20 minutes to melt the frozen shrimp; release the soaking water from the bottom of the tank, and then Rinse with 100 liters of pure water at 4-6°C and drain;

(2) Add 500 liters of 95% ethanol to the above-mentioned stainless steel extraction tank, mix evenly to obtain a mixed solution A, the content of ethanol in the mixed solution A is 70% (the volume percentage of ethanol in the liquid in the mixture A), and use a gear The pump circulates, so that the two phases are fully stirred, mixed and crushed, and then inserted into the high shear machine from the top, and run at 10000rpm for 15min;

(3) Start the decanter centrifuge, add the material in the gear pump to the inlet of the decanter centrifuge, and the two ends of the centrifuge flow out the ethanol liquid and the shrimp mud with a very low moisture content;

(4) Add shrimp paste and 500 liters of absolute ethanol into the stainless steel extraction tank, mix well to obtain mixture B, the content of ethanol in mixture B is 90% (the volume percentage of ethanol in the liquid in mixture B) and stir for 30 minutes Carry out leaching, static layering, and filter off the alcohol phase; add 500 liters of absolute ethanol, repeat the extraction, combine the extracts, and use a rotary bracket evaporator to remove ethanol under vacuum. During the process, heat with a low-pressure steam jacket to collect the oily liquid krill flowing out from the bottom outlet of the rotary bracket evaporator; that is, after taking out the filter residue in the stainless steel tank, use 80°C hot air to remove ethanol, and the removal is completed. The final dry matter can be used as feed.

The obtained product is dark reddish brown and is flowable. The product can be filled with capsules, and the content of the capsules is not cloudy, indicating that the prepared product is transparent and in good condition.

The phospholipid content measured by the molybdenum blue colorimetric method is 40.5%, and the lecithin content in the phospholipid is more than 70%.

Claims (17)

1. a preparation method for krill oil, is characterized in that: described preparation method comprises following stepRapid:

(1) krill is cleaned, drained, mix with extractant, obtain mixture A, shear; InstituteThe extractant of stating is C_2-4Alcohol or C_2-4The aqueous solution of alcohol, the addition of described extractant is everyIn the krill of 0.5-1.5kg, add the extractant of 1L; In the time that described krill is freezing krill, to krillThaw, then clean, drain; The described method of thawing is: under 10-20 DEG C of condition, by instituteThe freezing krill of stating mixes with water, soaks; After described mixing, described mixingThe content of the alcohol in thing A is 40%-80%; Described percentage is that described alcohol accounts for described mixture AIn the percent by volume of liquid; The speed of described shearing is 5000-12000rpm;

(2) Separation of Solid and Liquid, obtains shrimp mud; The method of described Separation of Solid and Liquid is centrifugation; DescribedThe separation factor of centrifugation is for being greater than 2500;

(3) described shrimp mud is mixed with extractant, obtains mixture B, extract, obtain extract,Desolvation; Described extractant is C_2-4Alcohol or C_2-4The aqueous solution of alcohol, describedThe addition of extractant is the extractant that adds 1-2L in the krill of every 1kg; After described mixing,The content of the alcohol in described mixture B is 90%-95%, and described percentage is described in described alcohol accounts forMixture B in the percent by volume of liquid.

2. preparation method as claimed in claim 1, is characterized in that: described alcohol is C_2-3Alcohol.

3. preparation method as claimed in claim 2, is characterized in that: described alcohol is ethanol, justOne or more in propyl alcohol and isopropyl alcohol.

4. preparation method as claimed in claim 1, is characterized in that: in step (1), describedThe addition of extractant is the extractant that adds 1L in the krill of every 1kg;

In step (1), after described mixing, the content of the alcohol in described mixture A is50%-70%; Described percentage is the percent by volume that described alcohol accounts for the liquid in described mixture A;

In step (3), the shrimp mud that the addition of described extractant is every 1kg adds the extractant of 1L.

5. preparation method as claimed in claim 1, is characterized in that: in step (1), describedThe speed of shearing is 10000rpm; The time of described shearing is 5-15min.

6. preparation method as claimed in claim 5, is characterized in that: the time of described shearing is10min; Described shearing is carried out in high-speed shearing machine.

7. preparation method as claimed in claim 1, is characterized in that: in step (2), describedThe separation factor of centrifugation is 2500-3000; The time of described centrifugation is 10-20min.

8. preparation method as claimed in claim 7, is characterized in that: described centrifugation timeBetween be 15min; Described centrifugation is for being used desk centrifuge or horizontal screw centrifuge centrifugal.

9. preparation method as claimed in claim 1, is characterized in that: in step (3), describedThe method of desolvation is vacuum removal solvent under the temperature conditions below 60 DEG C.

10. preparation method as claimed in claim 9, is characterized in that: the described temperature of deviating from solventDegree is 40-55 DEG C; The time of described desolvation is 10-30min.

11. preparation methods as described in claim 1-10 any one, is characterized in that:

In step (1), the concentration of the aqueous solution of described alcohol is more than 90%, and described percentage is instituteThe alcohol of stating accounts for the percent by volume of the aqueous solution of alcohol.

12. preparation methods as claimed in claim 11, is characterized in that: the aqueous solution of described alcoholConcentration be 95%.

13. preparation methods as described in claim 1-10 any one, is characterized in that:

In step (1), described drains as naturally draining;

The described time of thawing is in 30min; The consumption of described water is not have described freezing phosphorusShrimp.

14. preparation methods as described in claim 1-10 any one, is characterized in that: step (1)In, before described shearing, described krill and described extractant are stirred, and pulverize.

15. preparation methods as claimed in claim 14, is characterized in that: the method for described pulverizingPulverize for using gear pump.

16. preparation methods as described in claim 1-10 any one, is characterized in that:

In step (3), described being extracted as stirred and extracted; The time of described extraction is 20-40min;

In step (3), the number of times of described extraction is 2-3 time; When described extraction time is greater than 1When inferior, merge extract.

17. preparation methods as claimed in claim 16, is characterized in that: the time of described extractionFor 30min.