JP2005179215A - Method for extracting taurine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for extracting taurine contained in oyster at a high purity using a simple device. <P>SOLUTION: To raw oyster, is added with water in an amount 1.5-2 times the oyster, and the mixture is subjected to hot-water extraction by boiling it for one hour at 100°C. To the resulting extract, is added ethanol so that the mixture has an ethanol concentration of 50-80 vol%, thereby obtaining a precipitate and a supernatant. The precipitate is dried in a drum dryer to obtain a powdery oyster extract. The supernatant is concentrated to a Brix concentration of 50 wt% or more, cooled to 30°C, and further to -25°C to precipitate crude crystals of taurine, which are separated by suction filtration. The purity of taurine can be increased by the operation in which the separated taurine is dissolved in hot water and cooled for separation thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for efficiently extracting taurine while obtaining oyster meat extract by hot water extraction of oyster meat.

Taurine is abundant in shellfish such as oysters, mollusks, and fish. To extract taurine, seafood extracts are extracted by ion exchange, electrodialysis, precipitation using an organic solvent, or the like.
JP-A-61-58557 JP-A-8-10503

When taurine is extracted by electrodialysis, two steps of primary dialysis and secondary dialysis and desalting are required, and free amino acids such as glycine and glutamic acid are also included in the taurine fraction. It is difficult to make it 50% by weight or more, and in order to increase the purity, further purification is required.
In the ion exchange method, two columns of a cation exchange resin and an anion exchange resin are used, and a desalting operation is required, and an operation using a large amount of acid and alkali is necessary for regeneration of the ion exchange resin. It is.

The conventional method requires a large-scale apparatus and expensive chemicals, and thus has a drawback of high cost.
The present invention is intended to extract taurine from oyster meat by simple means without requiring large facilities for taurine contained in oyster meat.

  In the method for extracting taurine of the present invention, ethanol is added to an extract obtained by extracting raw oyster meat with hot water to remove the precipitate, and the precipitate is collected to obtain a oyster meat extract, and then the supernatant is concentrated. The concentrated liquid is cooled to less than zero degrees Celsius to precipitate taurine, which utilizes the large difference in solubility depending on the temperature of taurine.

  Moreover, after adding ethanol to the extract obtained by extracting hot oyster meat with hot water and precipitating and separating the extract, the Brix concentration of the concentrate containing the ethanol is concentrated to 40 to 70% by weight. Taurine is precipitated by cooling.

  As shown in the process diagram of FIG. 1, first, 1.5 to 2 times the amount of water is added to raw oyster meat, boiled at 100 ° C. for about 1 hour, extracted with hot water, and the solid content is removed by filtration. Ethanol is added to the extracted solution to a concentration of 50 to 80% by volume to obtain a precipitate and a supernatant. The precipitate is dried with a drum dryer to obtain a powdery oyster meat extract.

The supernatant is concentrated by evaporating and removing the ethanol contained by heating concentration method and vacuum concentration method until the Brix concentration exceeds 50% by weight. In the heat concentration, it is desirable to keep the heating temperature at 80 ° C. or higher.
The degree of concentration varies depending on the taurine content of raw oysters, etc., but is preferably performed until the Brix concentration is 40 to 70% by weight.
If the Brix concentration is less than 40% by weight, taurine may not be efficiently precipitated even if the concentrated solution is cooled in the subsequent step. If the Brix concentration exceeds 70% by weight, the viscosity of the concentrated solution becomes too high. It becomes difficult to separate the precipitated taurine.
This concentrated liquid is cooled with water, cooled to 30 ° C., and further brought to −25 ° C. to precipitate crude taurine crystals.
As shown in FIG. 2 showing the relationship between the Brix concentration of taurine and the freezing temperature, this concentrated solution does not freeze even at −25 ° C. when the Brix concentration is 50% by weight or more, and taurine is efficiently precipitated.

The precipitated taurine crystals are separated by (suction) filtration.
Further, the separated taurine crystals are dissolved in hot water at 80 ° C. with stirring, and cooled to room temperature. The solution is brought to 2 ° C. to precipitate taurine crystals. The concentrated solution in which the taurine crystals are deposited is filtered again (suction) to separate the taurine crystals, and the filtrate is recovered and reused by being reused in the extraction process. When taurine is dissolved, an adsorbent such as activated carbon is mixed to adsorb impurities in the solution, and decolored taurine can be obtained.
Through the above steps, taurine having a purity of 70% is obtained.

  When obtaining taurine having a purity of 90% or more, dissolve the above-mentioned 70% purity taurine crystals in a large amount of hot water at 70 ° C., add activated carbon, stir, and use a Buchner funnel pre-coated with a filter aid. A taurine crystal having a purity of 80% or more is obtained by suction filtration. Further, when it is necessary to increase the purity, a small amount of water is added to the taurine crystals, dissolved by heating at 80 ° C. or higher, and then recrystallized. By this operation, taurine having a purity of 90% can be obtained.

  The mother liquor from which taurine crystals have been separated is a highly tasteful liquid containing many types of free amino acids at high concentrations, and therefore can be used as a raw material for seasonings or as it is as a seasoning.

2.0 liters of distilled water was added to 1.3 kg of frozen raw oyster meat, and the mixture was heated and extracted at 100 ° C. for 40 minutes to remove the solid content, thereby obtaining an extract of oyster meat. Ethanol was added to the concentrate to a final concentration of 75% (volume) to cause precipitation, and the mixture was allowed to stand at room temperature for 2 to 4 days.
The precipitate was separated, and the precipitate was dried with a drum dryer at 140 ° C. to be powdered to obtain oyster meat extract powder. 60-70% of taurine in raw oyster meat is contained in the precipitate, that is, in the oyster meat extract powder, and the remaining 30-40% is contained in the supernatant.

The supernatant containing ethanol at a high concentration had a Brix concentration of 12% by weight. The supernatant was heated and concentrated 5 to 6 times to a Brix concentration of 60% by weight. Ethanol was removed from the supernatant by evaporation and evaporation by heating. Concentration efficiency is improved by reducing the pressure during the heat concentration.
The concentrated liquid was placed in a freezer at −20 ° C. for 10 hours to cool to precipitate taurine, and suction filtered through a Buchner funnel to separate taurine crystals.

  After adding 10 ml of water to 6.0 g of taurine crystals prepared in Example 1 and heating to 80 ° C. or higher to dissolve taurine, the solution was filtered while maintaining the temperature of the solution at 80 ° C. or higher. The liquid was cooled under the same conditions as in Example 1. The precipitated taurine crystals were separated by suction filtration and dried to obtain 2.8 g of taurine crystals having a purity of 80.1% by weight. Other free amino acids other than taurine were not included.

In the method for extracting taurine of the present invention, after adding ethanol to an extract obtained by extracting oyster meat with hot water to obtain a precipitate, the supernatant is concentrated and the concentrated solution is cooled to precipitate taurine as crystals. Therefore, compared with conventional electrodialysis, ion exchange, and preparative chromatography, taurine can be produced at low cost by a simple method that uses the solubility characteristics of taurine without requiring large-scale and expensive equipment. Can be extracted.
In addition, the supernatant after obtaining ethanol by adding ethanol to an extract obtained by extracting oyster meat with hot water has a limited field of application, but according to the present invention, taurine can be obtained efficiently and at low cost. It was possible to increase the utility value.

The process drawing of the taurine extraction method of this invention. The graph which shows the Brix density | concentration of taurine, and the freezing temperature.

Claims (5)

A method for extracting taurine, in which oyster meat is extracted with hot water, ethanol is added to the extract and the resulting supernatant is concentrated, and the concentrate is cooled to below zero degrees Celsius to precipitate taurine. Oyster meat is extracted with hot water, ethanol is added to the extract, the supernatant is concentrated, and the concentrated solution is cooled to below zero degrees Celsius to precipitate taurine, which is then filtered into hot water. A method for extracting taurine, which is dissolved and then cooled to precipitate taurine. The method for extracting taurine according to claim 2, wherein the taurine is decolorized by adding an adsorbent during hot water dissolution. The method for extracting taurine according to claim 3, wherein the adsorbent is activated carbon. The method for extracting taurine according to any one of claims 1 to 4, wherein the concentrate is concentrated until the Brix concentration of the concentrate is 30 to 90% by weight.

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