WO2010038964A2 - Method for extracting and separating active ingredients from krill, and related products - Google Patents

Abstract

The present invention relates to a method for extracting active ingredients from krill. The present invention provides a method for selecting, fractionating, extracting, and separating special nutritious ingredients through each step of extraction using supercritical carbon dioxide and a single solvent of ethanol or a mixed solvent of ethanol and the like by a supercritical carbon dioxide extraction system. The present invention provides oil products with rich astaxanthin and omega-3 unsaturated fatty acid, high purity phospholipid products having phospholipids of 80% or higher, and other protein products by varying the extraction conditions such as solvent, pressure, temperature, solvent injection speed, and total amount of solvent, etc. The present invention also provides a method for separating the products. The present invention is advantageous as it eliminates the necessity of solvent removing processes and produces high-quality protein products with solvent rarely remaining.

Description

Extraction and separation of useful components from krill and related products

The present invention relates to a method for extracting krill, and more particularly, using a special nutrient contained in krill using an extraction separation method using a pressurized liquid, supercritical carbon dioxide, such as astaxanthin, omega-3 polyunsaturated fatty acid ( ω-3 poly unsaturated fatty acid (ω-3 PUFA) and phospholipids, and recovering protein from the remaining extract.

Krill is a small shrimp-like zooplankton that is distributed in clean areas of the Antarctic waters and is located at the bottom of the food chain, so there is little risk of accumulation of heavy metals. It is also known to contain more polyunsaturated fatty acid-bound phospholipids relative to other aquatic organisms.

Dehydrated krill contains about 20% lipids, of which about 50% are phospholipids, and about 40% of the phospholipids form omega-3 fatty acid-bound forms containing EPA and DHA. In addition, the lipids contained in krill have been found to contain a large amount of the antioxidant astaxanthin.

Omega-3 fatty acids account for 40% of the fatty acids that make up the brain and 60% of the fatty acids that make up the retina, and are known to be found in blue fish and fish oils such as sardines, mackerel, and saury. These omega-3 fatty acids are known to help improve triglycerides and cholesterol in the blood to help blood flow smoothly and to relieve the symptoms of cardiovascular diseases.Inhibiting platelet aggregation and lowering blood pressure can lead to brain cells It is known to suppress or destroy lipids to alleviate or prevent dementia. Since such unsaturated fatty acids are not produced sufficiently in the body, it is known that they should be consumed steadily through food and the like.

However, krill is known to have a higher ratio of phospholipid-bound omega-3 polyunsaturated fatty acids than other marine and aquatic organisms. The form combined with phospholipids improves absorption, body utilization, and physiological effects compared to neutral lipids.

Astaxanthin, on the other hand, is a natural carotenoid with a strong antioxidant power, nicknamed supervitamin E. It is known that the antioxidant power, which is the ability to remove excess oxygen generated in the body, is superior to β-carotene and vitamin E. The ability to remove singlet oxygen, which is particularly toxic among free radicals, is 100 times higher than that of vitamin E, and More than ten times have been found through experiments. In addition, it has been confirmed in recent studies that 800 times higher than CoQ10, which is known to have high antioxidant power. When free radicals bind to fatty acids in tissues, they become fat peroxides, which oxidize tissues to cause lifestyle diseases or damage DNA by damaging DNA. Astaxanthin has a 1,000-fold inhibitory effect on the production of fat peroxide. have.

Various methods have been disclosed for extracting oils from marine and aquatic animals, and in particular, methods of extracting oils from fish using organic solvents such as hexane and ethanol have been widely performed. In addition, a solvent such as acetone may be used to determine fat content in fish muscle tissue.

U.S. Patent No. 4,331,695 discloses the use of a pressurized solvent that is gaseous at room temperature, such as propane, butane or hexane. This extraction method is carried out at a desired temperature of 15 to 80 ° C. for finely chopped vegetables or finely ground animal products. Thereafter, the extracted oil is solidified under high temperature and high pressure conditions of 50 to 200 ° C. Hexane, however, is an undesirable solvent for the extraction of marine animals such as krill. Moreover, the high temperatures used in the condensation step are disadvantageous by modifying the lipids.

Canadian Patent Application No. 1,098,900 discloses a method for extracting oil from krill. This method involves emulsifying fresh or thawed krill in an aqueous medium. The oil fraction extracted from the krill emulsion is recovered by centrifugation. In addition, in the conventional literature (Folch, "A simple method for the isolation and purification of total lipids from animal tissues" 1995) has been presented an extraction method using a mixture of chloroform and methanol as a solvent. However, this method cannot be used in food because of the toxicity of the solvents used.

US Pat. No. 6,800,299 uses low temperature extraction of organic solvents such as acetone and ethanol from krill, but this method requires a large amount of organic solvent.

According to Korean Patent Application No. 10-2001-7004998 and its PCT international patent application PCT / CA1999 / 000987 "lipid extraction method from marine and aquatic animal tissue", the lipid fraction is extracted from marine and aquatic animal material by acetone extraction. The method provides, and the resulting insolubles and granulated fractions disclose the extraction of soluble lipid extracts by applying additional solvent extraction with alcohols, isopropanol, etc., but this also concerns the residual acetone in the krill extract product. However, there is a problem that the extraction process step is complicated, and the energy cost for removing acetone and additional solvent is expensive.

In addition, the lipid extracted by acetone will contain a lot of free fatty acids and saturated fatty acids, which will lead to the deterioration of the quality of the krill extract product unless a separate purification process.

K. Yamaguchi et al., In a paper (J.Agric. Food Chem. 1986 34, 904-907), extracted non-polar lipids (mostly triglycerides) using supercritical carbon dioxide extraction from krill. Phospholipids were not extracted.

Y. Tanaka and T. Ohkubo (J. Oleo. Sci .; 2003), 52, 295-301 and Y. Tanaka et al. (J. Oleo. Sci; 2004; 53, 417-424) extracted phospholipids by adding 10%, 15% and 20% ethanol in a freeze-dried salmon using a mixed solvent of supercritical CO ₂ and cosolvent (ethanol). It has been reported that more than 80% of phospholipids are extracted when phospholipids are above 30% and 20% in%.

In particular, in WO 08060163 Al, krill is heated at 80-90 ° C. for 5 minutes and extracted with triple ethanol to dehydrate water and final extraction of krill foil with co-solvent (ethanol) 10% at 280-300 bar pressure with supercritical CO ₂ . Although dehydration with ethanol after catching krill has the advantage of minimizing the degeneration of nutrients of krill, extraction with ethanol solvent pre-treatment with phospholipids as well as neutral lipids. As it is difficult to obtain a high-purity phospholipid extract, the extracted krill foil also has a disadvantage that requires a separate process for removing the solvent, such as ethanol.

In the above-described prior art, due to the problem of residual organic solvents that are harmful to the human body, it is not preferable to be used for actual foods or pharmaceuticals, but also useful for foods or pharmaceuticals such as astaxanthin, omega-3 unsaturated fatty acids, phospholipids, etc. Extraction of high purity of special nutrients was difficult, and additionally, there was a disadvantage in that the additional costs incurred additionally by additionally adding a separate purification process.

The present invention has been made in view of the above-mentioned disadvantages, and in extracting useful nutrients from krill, without using organic solvents such as hexane or acetone, which are harmful to the human body, among the useful nutrients that krill has, Exploring and separating tarxanthin, omega-3 polyunsaturated fatty acid (ω-3 PUFA), phospholipids, etc., and separating and refining each nutritional ingredient as necessary Alternatively, the present invention has a purpose of establishing a method of allowing protein to be recovered without remaining solvent from krill foil remaining after extraction, while allowing mixing.

The above object of the present invention is suitable for extracting nutrients to be extracted from krill, while extracting only useful nutrients from krill by applying an extraction method using supercritical carbon dioxide as a solvent that is harmless to the human body, the supercritical carbon dioxide Optimized the method of fractionation, extraction and separation using different solubility difference according to temperature and pressure in the process, and the fractionation process continuously without moving the filling sample with the raw material once filled in the extractor By the process to be achieved.

The present invention provides a novel pretreatment method that improves the problems of the krill ethanol dehydration method.

Method of pretreatment of krill according to the present invention is characterized in that the krill is immediately caught by 80 ~ 100 ℃, pulverized and dried immediately on the ship to prepare a powder.

Another method of pretreatment of krill according to the present invention is to catch the krill as soon as 80 ~ 100 ℃ to quickly freeze without the addition of seawater or fresh water is added to the immediate freezing immediately stored and stored in the frozen state, then After drying or crushing, the surface water is removed by a dehydrator and immediately dried by hot air drying to obtain a water content of less than 5% to prepare a powder. Through this krill pretreatment process, it is possible to obtain a high purity phospholipid extract in the subsequent extraction process.

The present invention also provides a method of extracting krill powder using supercritical carbon dioxide and ethanol as an extraction solvent.

Extraction method of krill according to the present invention, the step of pre-processing the raw material krill to powder; Filling the krill powder into an extractor; Extracting krill powder using supercritical carbon dioxide and ethanol as an extraction solvent; Supplying only the supercritical carbon dioxide to the extractor to remove ethanol from the remaining krill extraction foil to obtain krill protein extraction foil; And concentrating the krill extract under reduced pressure to remove ethanol to obtain krill oil.

Extraction using the supercritical carbon dioxide and ethanol as the extraction solvent is preferably carried out under a temperature of 50-70 ℃ and 250 to 800 atmospheres, the average flow rate of ethanol is preferably 5-50% of the flow rate of carbon dioxide. Do.

Krill oil and krill protein extract foil are finally obtained from krill powder through the same method as described above.

In addition, the method of extracting krill according to the present invention comprises the steps of pretreating the raw material krill to powder; Filling krill powder into an extractor; Performing primary extraction of krill powder using supercritical carbon dioxide as an extraction solvent to obtain krill oil; Performing secondary extraction using supercritical carbon dioxide and ethanol as extraction solvent to obtain krill oil, and supplying supercritical carbon dioxide to the extractor to remove ethanol from krill extraction foil to obtain krill protein extraction foil continuously It provides a method of extracting krill, characterized in that performed.

Extraction using the primary supercritical carbon dioxide and extraction using the secondary supercritical carbon dioxide and ethanol are preferably performed under pressure conditions of 250 to 800 atm, respectively.

Krill oil is obtained as a primary extract through the same method as described above, and krill protein extract foil containing protein as a main component as krill oil and a residue as a secondary extract is obtained.

In addition, the method of extracting krill according to the present invention comprises the steps of pretreating the raw material krill to powder; Filling krill powder into an extractor; Performing primary extraction of krill powder using supercritical carbon dioxide as an extraction solvent to obtain krill-flavored concentrated oil; Performing second extraction using supercritical carbon dioxide as the extraction solvent to obtain a high krill astaxanthin oil; Performing tertiary extraction using supercritical carbon dioxide and ethanol as extraction solvent to obtain krill phospholipid high oil, and supplying supercritical carbon dioxide to the extractor to remove ethanol from krill extract foil to obtain krill protein extract foil It provides a method of extracting krill, characterized in that is carried out continuously.

The extraction using the primary supercritical carbon dioxide is preferably performed at a pressure condition of 80 to 250 atm, and the extraction using the primary supercritical carbon dioxide is preferably performed at a pressure condition of 250 to 800 atm.

Through the above method, krill-flavored concentrated oil is obtained as the first extract, and krill astaxanthin-containing oil is obtained as the second extract, and krill phospholipid-containing oil is obtained as the third extract, and protein as a residue is obtained. Krill protein extract foil which contains as a main component is obtained.

Krill oil obtained by the method according to each of the present invention as described above is rich in EPA, DHA omega-3 fatty acids and phospholipids can be used as a raw material for various food processing.

In addition, krill protein extract gourd can be used as a raw material for various seasonings by fermenting the amino acid as a main component.

The present invention focuses on the fact that the lipids contained in krill have both neutral lipids and phospholipids. First, the free fatty acid, saturated fatty acid, and krill scent components having relatively low molecular weight and high probability of rancidity among the neutral lipids are preferentially. Fractional extraction is followed by fractional extraction of unsaturated fatty acids in triglycerides, and finally fractional extraction of phospholipids.

Accordingly, in the present invention, supercritical carbon dioxide having high penetration, diffusion rate, and dissolving ability are used as the solvents of the first and second extractions, and the third extraction solvent easily dissolves phospholipids in addition to the supercritical carbon dioxide. Harmless ethanol was used alone or in a mixed solvent thereof.

As described above, the primary and secondary extraction steps are for fractional extraction of neutral lipids, using the difference in solubility of the supercritical carbon dioxide according to the pressure, temperature and flow rate of the composition ratio according to the antioxidant and fatty acid type. Firstly, the fragrance components, free fatty acids and neutral lipids of relatively small molecular weight are screened and extracted under pressure of less than 250 atm. Secondly, unsaturated fatty acids and astaxanthin having high molecular weight are selected and extracted from neutral lipids under pressure of more than 250 atm. It was.

Supercritical carbon dioxide has a high solubility in neutral lipids but little solubility in phospholipids, making it a suitable solvent for extracting only neutral lipids. Therefore, when supercritical carbon dioxide is brought into contact with dry krill powder, only neutralized lipids such as triglycerides are extracted by dissolving and extracting only phospholipids and proteins as a main component in relation to its affinity.

As such, neutral lipids are extracted from krill powder through primary and secondary extractions using supercritical carbon dioxide, and insoluble components such as proteins are left through tertiary extracts using a mixed solvent of supercritical carbon dioxide and ethanol or a single ethanol solvent. It is possible to extract high purity phospholipids with low content of neutral lipids. Subsequently, after extracting lipids, krill powder (mainly protein) is contacted with pure supercritical carbon dioxide to remove residual liquid solvent (ethanol, etc.), thereby recovering krill powder containing protein as a main component.

In other words, the present invention is the contact solvent and pressure, temperature, solvent dosing rate, the total amount of the solvent and the like to extract the fractional fractionation step by step while contacting a mixed solvent of supercritical carbon dioxide and supercritical carbon dioxide and ethanol or a single ethanol in the same extractor It has the characteristics to manufacture various related products of high purity desired by different extraction conditions.

Hereinafter, with reference to the accompanying drawings will be described in detail the extraction separation and recovery method of the krill-related products using carbon dioxide and co-solvent according to the embodiments of the present invention. However, the scope of the present invention is not limited to the following embodiments, numerical changes, simple change of components within the scope without departing from the technical matters of the present invention by those skilled in the art to which the present invention belongs. It may be implemented in a variety of other forms, such as technical changes are included within the scope of the invention.

Machines and apparatuses used in the present invention is a fluid supply unit consisting of a precooler and a piston pump, an extractor unit consisting of a preheater and an extractor, the fluid in the state containing the omega-3 polyunsaturated fatty acid-bound phospholipids, etc. separated into extracts and gaseous state It consists of a separating section for the separation, a condenser for cooling the evaporated carbon dioxide and a recovery section for storing the carbon dioxide cooled and liquefied. The separation section and the recovery section used in the ethanol extraction process are configured separately. The condenser consists of a vacuum distillation unit for removing ethanol, an ethanol condenser and an ethanol reservoir.

A schematic structure diagram for the practice of the present invention is shown in FIG. Solvents such as carbon dioxide are supplied to the extractor in a liquid or supercritical state having a constant temperature and pressure while passing through the precooler and the piston pump, and have a predetermined temperature while passing through the preheater. A solvent such as carbon dioxide maintains a constant temperature and pressure in the extractor and extracts the neutral lipids and phospholipids contained in the krill powder packed therein.In the separator, the extract and the supercritical fluid are separated into gases and the separated gases It is recycled as it is converted to a liquid via a condenser.

Hereinafter, the process steps of the present invention will be described in more detail with reference to FIG. 1.

(A) Raw material filling process

Krill powder is added to the extractor (EX).

(B) Extraction solvent supply process

In order to use carbon dioxide as an extraction solvent, the temperature of the preheater H1 is set to 70 ° C and the precooler H2 to -5 ° C. Carbon dioxide from the vessel passes through the precooler and enters the pump in a complete liquid state at -5 ° C. In the pump, carbon dioxide is supplied to the extractor at a flow rate of 30 g / min, and is primarily heated while passing through the preheater (H1). With the allowable pressure of the decompression device (V1: BPR) set to 400 atm, the carbon dioxide inside the extractor is heated and pressurized until it reaches a supercritical state of 400 atm and 70 ° C. When the pressure inside the extractor reaches 400 atm, The device discharges more than a certain pressure to the outside and the pressure inside the extractor is maintained at 400 atm.

(C) neutral lipid extraction process

As the carbon dioxide is continuously supplied and discharged during the extraction process, supercritical carbon dioxide at 400 atm and 70 ° C. extracts neutral lipids and astaxanthin from krill and insoluble components such as phospholipids and proteins remain.

(D) Neutral lipid recovery process

Supercritical carbon dioxide containing neutral lipids is sent to the separator (S1) through a decompression device. At this time, at room temperature and atmospheric pressure, the carbon dioxide loses its dissolving power in the supercritical state and recovers the neutral lipid and astaxanthin dissolved in the supercritical carbon dioxide. The gaseous carbon dioxide is converted into a liquid phase through the condenser (C1) and stored in the recovery tank (R1) and used again for extraction.

(E) Phospholipid Extraction Process

After sufficiently extracting the neutral lipid contained in the krill through a continuous extraction process of 2 hours, using an ethanol as a co-solvent to operate the ethanol pump (P2) and simultaneously supply to the extractor at a flow rate of 5-50% of the carbon dioxide flow rate. The secondary extraction process using a mixed solvent of ethanol and carbon dioxide elutes the phospholipids remaining in the krill with high purity and leaves other components constituting the residual components, that is, various proteins, as insoluble components.

(F) phospholipid recovery process

As in step (d), the phospholipid is decomposed into the liquid and gaseous carbon dioxide of the ethanol containing the dissolved component in the separator (S2) while decompressing the mixed solvent of supercritical carbon dioxide and ethanol through a depressurization device. And liquefied to the recovery tank (R2) to be used for extraction. The liquid ethanol and elution components are sent to the ethanol evaporator (E1) for concentration and recovery. The evaporated ethanol is liquefied in the ethanol condenser (C3), collected in an ethanol recovery tank (R3) and sent to the ethanol storage (T1) for extraction. do.

Krill extract foil ethanol removal process

In the extractor, nutrients such as proteins that do not dissolve in both supercritical carbon dioxide and mixed solvents (supercritical carbon dioxide-ethanol) remain as residual ingredients, and the residual ethanol is removed by extracting using only supercritical carbon dioxide to increase its utilization. .

While preferred embodiments of the present invention have been described above with reference to the drawings, those skilled in the art may vary the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be understood that modifications and changes can be made.

As described above, the present invention has the effect of easily producing a high quality product having an omega-3 unsaturated fatty acid content of 40% or more and a phospholipid concentrate product having a phospholipid content of 80% or more, and by optimizing the extraction conditions, etc. There is a feature that can adjust the content ratio of the useful ingredient to the extract or the extract of each step of the extract mixture.

In addition, the present invention can be fractionally extracted by a continuous operation process in the same extractor, it is possible to compactly design the whole extraction equipment.

According to the present invention, even if a trace amount of residual solvent is included in the final extract by performing extraction using carbon dioxide and ethanol, which are harmless to the human body, there is no problem in safety.

In particular, carbon dioxide is easy to remove because it is a gas at room temperature and atmospheric pressure, and in the case of ethanol, it is easy to remove by vacuum distillation.

In general, in an extraction method using an organic solvent, the organic solvent is often left in a significant proportion in the residue of the extraction tank. However, the present invention uses supercritical carbon dioxide in the final extraction step, so that almost no solvent, such as ethanol, remains in the final krill foil after the extraction process, so it can be used without a separate solvent removal process has excellent economic efficiency.

1 is a structural diagram of an extraction apparatus using a pressurized liquid and supercritical carbon dioxide used in the present invention.

2 is a flowchart illustrating an extraction process of krill powder according to Example 2 of the present invention.

3 is a flowchart illustrating an extraction process of krill powder according to Example 3 of the present invention.

4 is a flowchart illustrating an extraction process of krill powder according to Example 3 of the present invention.

<Short description of the symbols in the drawings>

P1: CO2 Feed Pump

P2: Ethanol Feed Pump

P3: vacuum pressure pump

H1: Where the supercritical phase is created by supplying heat to the compressed carbon dioxide

H2: Where to cool CO2 before supplying it to the pump

EX: Where to fill and extract krill powder

V1: Pressure regulating valve with Back Pressure Regulator

S1: Where to vaporize carbon dioxide and separate it from the extract

S2: Where to separate the extract mixed with ethanol by vaporizing carbon dioxide

C1: where the vaporized carbon dioxide is cooled to condense into a liquid

C2: where the vaporized carbon dioxide and a small amount of ethanol are cooled to condense into a liquid

C3: where condensed vaporized ethanol into a liquid

R1: A place to recover liquefied carbon dioxide and send it to a circulation pump

R2: A place to recover liquefied carbon dioxide and a small amount of ethanol and send it to a circulation pump

R3: Where to recover liquefied ethanol

E1: Where to extract and concentrate ethanol solution separated from carbon dioxide

T1: where the recovered ethanol is stored and sent to the ethanol pump

Example 1 Ethanol% Crystallization Experiment

130 g of krill powder was placed in the extractor under conditions of a temperature of 70 ° C. and a pressure of 400 atm, with an average flow rate of 30 g / min of carbon dioxide and an average flow rate of 10%, 20%, 30%, 40% and 50%, respectively. Extraction was carried out for a time (390 minutes, 195 minutes, 130 minutes, 97.5 minutes and 78 minutes) is injected into the ethanol 6 times compared to the sample filled with ethanol as the extraction solvent. After supplying pure carbon dioxide with an average flow rate of 30 g / min for 30 minutes to remove ethanol from the remaining krill extraction foil, and adjusting the pressure of the extractor to atmospheric pressure to recover the krill extraction foil, the mixed liquid remaining in the separator Distillation under reduced pressure to remove ethanol to prepare a krill extract.

The contents of EPA, DHA omega-3 fatty acids and phospholipids in the extracts were measured using gas chromatography and acetone insolubility, and the results are shown in Table 1 below. As shown in Table 1, the best results were obtained when the average flow rate of ethanol was 50% of the flow rate of carbon dioxide. Therefore, in the following examples, the average flow rate used 50% of ethanol relative to the flow rate of carbon dioxide.

TABLE 1

Example 2 Single Extraction of Krill Powder Using Carbon Dioxide and Ethanol Mixture

130 g of krill powder was placed in the extractor and extracted for 3 hours using 70 g of ethanol at an average flow rate of 30 g / min and 50% of the ethanol flow rate at an average flow rate of carbon dioxide under a temperature of 70 ° C. and a pressure of 400 atm. After that, pure carbon dioxide having an average flow rate of 30 g / min was fed for 30 minutes to remove ethanol from the remaining krill extraction foil. Subsequently, the pressure of the extractor was adjusted to atmospheric pressure to recover the krill extract foil, and the mixed liquid remaining in the separator was distilled under reduced pressure to prepare a krill extract from which ethanol was removed.

The contents of EPA, DHA omega-3 fatty acids and phospholipids of the krill extract obtained by using gas chromatography (Gas Chromatography) and acetone insolubility were measured, and the results are shown in Table 1 below.

TABLE 2

Example 3 Multiple Extraction of Krill Powder Using Primary and Secondary Carbon Dioxide and Ethanol Mixtures

130 g of krill powder was placed in an extractor, and primary extraction was performed for 2 hours using supercritical carbon dioxide having an average flow rate of 30 g / min as an extraction solvent under a temperature of 70 ° C. and a pressure of 400 atm. Subsequently, the supercritical carbon dioxide was transferred to a separator under reduced pressure to separate and recover the primary extract A from the carbon dioxide.

Subsequently, the extractor was subjected to secondary extraction for 2 hours using a solvent mixture of 50% of the average flow rate of 30 g / min carbon dioxide and 50% of the flow rate of the average flow rate carbon dioxide under a temperature of 70 ° C. and a pressure of 400 atm. Pure carbon dioxide was supplied to the extractor at an average flow rate of 30 g / min for 30 minutes to remove ethanol from the remaining krill extraction foil, and then the pressure of the extractor was adjusted to atmospheric pressure to recover the krill extraction foil. The remaining mixed liquid in the separator was distilled under reduced pressure to prepare a secondary extract B from which ethanol was removed.

The contents of EPA, DHA omega-3 fatty acids and phospholipids in the primary extract A, the secondary extract B, and the mixture of the two extracts were measured by using gas chromatography and acetone insolubility. The results are shown in Table 2 below.

TABLE 3

Example 4 Multiple Extraction of Krill Powder Using Primary and Secondary Carbon Dioxide and Tertiary Carbon Dioxide and Ethanol Mixtures

130 g of krill powder was placed in an extractor and subjected to a primary extraction for 2 hours using supercritical carbon dioxide having an average flow rate of 30 g / min as an extraction solvent under a temperature of 70 ° C. and a pressure of 200 atm. The primary extract A was separated and recovered from carbon dioxide by transporting under reduced pressure to a separator. Subsequently, the pressure was increased to 400 atm at a temperature of 70 ° C., and secondary extraction was performed for 2 hours using supercritical carbon dioxide having an average flow rate of 30 g / min as an extraction solvent, and then the supercritical carbon dioxide was transferred to a separator under reduced pressure. Tea extract B was separated and recovered from carbon dioxide.

Subsequently, after performing tertiary extraction for 2 hours using a mixed extraction solvent at a temperature of 70 ° C. and a pressure of 400 atm, carbon dioxide having an average flow rate of 30 g / min and ethanol having a flow rate of 50% of the average flow rate of carbon dioxide were mixed for 2 hours. Pure carbon dioxide with an average flow rate of 30 g / min was supplied for 30 minutes to remove ethanol from the remaining krill extraction foil, and the pressure of the extractor was adjusted to atmospheric pressure to recover the krill extraction foil. The mixed liquid remaining in the separator was distilled under reduced pressure to remove ethanol to prepare a tertiary extract C.

Contents of EPA and DHA omega-3 fatty acids and phospholipids in primary extract A, secondary extract B, tertiary extract C, and D mixed with B and C by using gas chromatography and acetone insolubility Were respectively measured and the results are shown in Table 3.

TABLE 4

Example 5 krill extract foil analysis

The protein content and amino acid composition of the protein for krill extraction foil prepared in Example 2 were analyzed, and the results are shown in Table 5 below.

TABLE 5

Comparative Examples 1 to 8

About 20 g of krill powder was mixed with 300 mL of various solvents and mixtures thereof for comparison with the present invention, and after performing Soxhlet extraction for 5 hours, the components of the obtained extract were analyzed and the results are shown in Table 6 below. .

TABLE 6

Comparing the results of the comparative example with the results of Examples 3 and 4, which are the method according to the present invention, the content of DHA omega-3 fatty acid and the content of DHA omega-3 fatty acid were not significantly different. The content of phospholipid was found to be significantly higher in extracts obtained by the method according to the invention, in particular the secondary extract of Example 3 and the tertiary extract of Example 4.

From this, the method of extracting krill using supercritical carbon dioxide according to the present invention can provide a product richer in DHA omega-3 fatty acids and containing a high concentration of phospholipids than in the conventional extraction method using an organic solvent.

As can be seen from the above, the present invention can be fractionated, extracted and recovered step by step, such as krill oil and krill protein products, further concentrated krill fragrance oil, high astaxanthin oil, high phospholipid oil, etc. It is a very useful invention for the special food processing industry because it has an excellent effect.

Claims (16)

In a method of extracting krill oil from krill powder by pre-treating the raw material krill and powdering, using supercritical carbon dioxide and ethanol as an extraction solvent, Extracting krill oil from krill powder using supercritical carbon dioxide and ethanol as an extraction solvent, supplying only supercritical carbon dioxide to the remaining krill extract foil to remove ethanol to obtain krill protein extract foil and the krill powder The extract was concentrated under reduced pressure to remove ethanol to obtain krill oil continuously. Extraction of krill powder using the supercritical carbon dioxide and ethanol as the extraction solvent is carried out under the conditions of the temperature of 65 ℃ to 70 ℃ and 400 to 450 atm, the average flow rate of ethanol is 40-50% of the flow rate of carbon dioxide Method for extracting krill, characterized in that. Pretreatment of the raw material krill to powdering; Filling krill powder into an extractor; Performing primary extraction of krill powder using supercritical carbon dioxide as an extraction solvent to obtain krill oil;  Performing a second extraction using supercritical carbon dioxide and ethanol as an extraction solvent to obtain krill oil, and supplying supercritical carbon dioxide to the extractor to remove ethanol from the krill extract foil to obtain krill protein extract foil; And Mixing the primary extract krill oil and secondary extract krill oil, and concentrated under reduced pressure to remove ethanol to obtain krill oil, characterized in that the step of extracting krill is carried out continuously. The method of extracting krill according to claim 2, wherein the pretreatment of the raw material krill is performed by pulverizing and drying the raw material krill to about 80 to 100 ° C. to prepare the powder. According to claim 2, wherein the pre-treatment step of the raw material krill is ripened to about 80 ~ 100 ℃ after rapid freezing without addition of seawater or fresh water immediately stored in the freezing immediately after moving to the land, the fine cutting in the frozen state Method of extracting krill, characterized in that by drying, or after crushing to remove the surface water with a dehydrator and immediately dried to less than 5% water content through drying. The method of claim 2, wherein the extraction using the primary supercritical carbon dioxide and the extraction using the secondary supercritical carbon dioxide and ethanol are each carried out at a pressure of 400 atm, the average flow rate of ethanol 5-50% of the flow rate of carbon dioxide Method for extracting krill, characterized in that. Krill oil extracted from krill powder by the method according to claim 2. Krill protein extract foil obtained from krill powder through the method according to claim 2. Pretreatment of the raw material krill to powdering; Filling the krill powder into an extractor; Performing primary extraction of krill powder using supercritical carbon dioxide as an extraction solvent to obtain krill-flavored concentrated oil; Performing second extraction using supercritical carbon dioxide as the extraction solvent to obtain a high krill astaxanthin oil; Performing tertiary extraction using supercritical carbon dioxide and ethanol as extraction solvent to obtain krill phospholipid high oil, and supplying supercritical carbon dioxide to the extractor to remove ethanol from krill extract foil to obtain krill protein extract foil Method for extracting krill, characterized in that is carried out continuously The method of extracting krill according to claim 8, wherein the pretreatment of the raw material krill is performed by pulverizing and drying the raw material krill at about 80 to 100 ° C. to prepare a powder. The method of claim 8, wherein the pretreatment of the raw material krill is about 80-100 ° C., and the raw material krill is rapidly frozen without addition of seawater or immediately frozen by adding fresh water, and then stored in a frozen state. Method of extracting krill, characterized in that to dry, or after crushing to remove the surface water with a dehydrator and immediately dried to less than 5% moisture content through drying to produce a powder. The method of claim 8, wherein the extraction using the primary supercritical carbon dioxide is performed at a pressure condition of 80 to 250 atm, and the extraction using the secondary supercritical carbon dioxide is performed at a pressure condition of 250 to 800 atm. How to extract krill. Krill-flavored oil prepared as a primary extract through the method according to claim 8. A high krill astaxanthin oil prepared as a secondary extract by the method according to claim 8. A krill phospholipid high content oil prepared as a tertiary extract through the method according to claim 8. Astaxanthin and phospholipid-rich krill oil having reduced krill fragrance and saturated fatty acid prepared by mixing the secondary extract and the tertiary extract through the method according to claim 8. Krill protein extract foil obtained as a residue by the method according to claim 8.

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