RU2109461C1 - Method of preparing jelly-forming agent from a mixture of marine red algae - Google Patents

Abstract

FIELD: food industry. SUBSTANCE: a mixture of red algae (Chondrua armatuc and Ahnfeltia tobuchiensis) is used for preparing carrageenan and agar which is subjected for preliminary demineralizing. Then carrageenan is extracted with water, carrageenan extract is purified and dried; or potassium ions are added to the purified extract followed by carrageenan potassium preparing. Carrageenan potassium is isolated by dehydration, pressing or by alcohol treatment followed by additional drying at 70 C, not above. After carrageenan isolation alga mixture residue is washed with sodium hydroxide at simultaneous addition of dry sodium chloride to solution. After alga residue washing to neutral reaction (pH 7) agar is extracted from residue, washed with fresh water to remove pigments followed by dehydration by pressing and drying at 60 C, not above. EFFECT: improved method of preparing.

Description

 The invention relates to the food industry, in particular to the processing of algae to obtain thickeners and gelling agents.

A known method of producing an agar-like product from a mixture of Baltic Baltic red algae phyllophora (Phyllophora brodiaei) and Furcellaria fastigiata (Furcellaria fastigiata) in a ratio (by weight) of 60-40 (Aut. St. USSR N 923503, MKI ⁴ A 23 L 1/04) , by treating them with alkali, washing, extracting and drying.

 The closest technical solution for the raw materials used is a method for producing a gel former from a mixture of red algae (Aut. St. USSR N 603367, class A 23 L 1/04, publ. 1976), where the red algae gracillaria Gracilaria verrucosa and phyllophora Phyllophora nervosa. The algae mixture is treated with alkali, the solution is drained, then the algae is treated with hot steam for 40-60 minutes, washed and extracted in an acid solution, followed by filtration and drying.

 On the Anfeltsian fields of the South Kuril ridge and Southern Primorye, a peculiar community of red algae, anfelium and chondrus, has formed, the proportion of chondrus in which ranges from 20 to 40%. Sorting algae from such a mixture is a labor-intensive technological operation, and for this reason the anfelia coming to the agar enterprises goes directly to the production of agar mixed with chondrus. The agar obtained from such raw materials does not meet the requirements of GOST. For this reason, Honda in a mixture with anfelium is considered as a mechanical impurity, impairing the yield and quality of agar. Chondrus, on the other hand, is an independent source of a valuable gelling agent such as carrageenan, which has damping and gelling properties. The technology developed at TINRO for the production of carrageenan from pure chondrus served as the basis for using this technology in the proposed method for extracting polysaccharides from a mixture of algae in the first stage of extraction — extraction of a polysaccharide of chondrus and carrageenan from a mixture of algae. Here, an exception is made to such a process as sorting chondrus from a mixture before extraction of carrageenan, which, as a rule, is associated with heavy manual labor.

 The problem to be solved by the invention is to obtain two carneginine and agar jelly-forming agents from a mixture of algae Chondrus armatus (spiny chondrus) and Ahnfeltia tobuchiensis (Far Eastern anfelia) by sequential extraction, the ratio of algae in the mixture is 20-80, 30-70, 40-60.

The essence of the invention lies in the fact that gelling agents are extracted in stages, while carrageenan is first extracted by treatment with water at a temperature of 60-70 ^o C for 2.5-3 hours, and agar is extracted from the remains of the algal mixture.

 It has been experimentally established that it is with the recommended pre-treatment regimen of the algal mixture that the thalli completely swell, algae tissue softens, which facilitates the removal of soluble inorganic salts, carbohydrate and free nitrogen-containing substances and some pigments.

After draining the water, the algal mixture is washed twice with cold water from the pigment, then it is poured with water, the mixture is heated to 60-70 ^o C and the carrageenan is extracted at this temperature for 150-180 minutes, the water module is 1: 10. Lowering the extraction temperature does not give a positive effect the completeness of extraction of carrageenan from the mixture, resulting in a low yield of the product. The increase in temperature is associated with an undesirable phenomenon - the release of low molecular weight agar fractions into the carrageenan solution, which negatively affects the quality of carrageenan. Extraction with a duration of 4 h and a water module of 1:10 contributed to the maximum yield of carrageenan. From the shorter duration and the hydromodule during the extraction process, the amount of carrageenan released from the mixture did not change in the direction of decreasing or increasing.

 The extract after separation from the boiled mixture of algae is purified by centrifugation or filtration through a layer of filter aid on press filters.

The purified extract is used to produce carrageenate. To do this, potassium hydroxide in an amount of 2-3% to the solids content of the extract at a temperature of 20-70 ^o C or potassium chloride at a temperature of the extract of 60-70 ^o C in an amount of 0.6-1.0% to the content is introduced into the purified extract solids in the extract, incubated for 120 minutes to complete the structuring of the gel.

 If potassium hydroxide is used, after the gel has been kept, the extract is neutralized by adding acid to pH 7 and left until gelation is complete.

The resulting gel is dried by pressing to a solids content of 13-14% and dried in a fluidized bed at a temperature not exceeding 70 ^o C.

 The resulting potassium carrageenan salt has the properties of a gelling agent.

 After isolation of carrageenan, the remainder of the algal mixture was washed in fresh water at room temperature from the solution of carrageenan remaining on the anfelium thalli. The technological principle of extracting agar from the residue of an algal mixture is to treat the remainder of the mixture with a 5% sodium hydroxide solution while simultaneously adding dry sodium chloride to a concentration of 3%, followed by washing with wash water to pH 7, extracting, filtering, gelling, pressing and drying .

 Processing the remainder of the algal mixture after extraction from the carrageenan mixture with an alkaline-salt mixture of NaOH + NaCl helps soften the cell wall of anfelia while blocking the agar in it. Recommended temperature, duration of treatment of the remainder of the mixture and the water module are most acceptable, because maximize polysaccharide recovery.

 Washing the algal residue with fresh water after pretreatment to a neutral reaction (pH 7) is achieved within 4-5 hours.

The extraction of agar from the prepared residue of the mixture is achieved by extraction at a temperature of 98-100 ^o C for 6 hours and a water module of 1:10. The recommended mode is most acceptable, because Anfelium boils well, resulting in maximum agar extraction.

 The yield of the finished product is maximum, up to 7% by weight of anfelium in the mixture.

Example 1. 50 g of an air-dry mixture of chondrus algae: anfelia in a ratio (by weight) of 20:80 is soaked in water at a temperature of 40 ^o C. Locking time 2 hours, water module 1:20. After soaking, the algal mixture is washed with water at a temperature of 18-20 ^° C. to pH 7 and the carrageenan is extracted from the algal mixture. The extraction of carrageenan is carried out at a temperature of 65 ^o C and a duration of 2.5 hours with a water module of 1:10. Then the carrageenan solution is centrifuged, precipitated with potassium chloride or treated with potassium hydroxide, dehydrated and dried. The yield of carrageenan was 21.5% of the air-dried algae chondrus, which is more than 60% of its content in algae. The strength of the gels of 2% solutions of carrageenan is 300 g according to Valence during precipitation with potassium chloride and 500 g according to Valence when treated with potassium hydroxide.

After the separation of carrageenan, the remainder of the algal mixture was washed in fresh water, after which the remainder of the mixture was treated with a 5% sodium hydroxide solution while dry sodium chloride was added to a concentration of 3% at a temperature of 70 ^o C. The processing time was 2.5 hours at a water ratio of 1: 20 After treatment, the alkaline-salt solution is drained, the water-salt residue is washed with tap water for 4-5 hours to pH 7. From the prepared mixture, the agar is extracted at a temperature of 98-100 ^o C. The duration of the extraction is 6 hours with a water module 1:10. The yield of agar is up to 7% by weight of anfelium in the mixture, which is 85% of its content in anfelium. The strength of 0.85% agar gel solutions is 350 g according to Valent. The melting point and gelation 82 and 33 ^o C, respectively.

Example 2. Extract carrageenan from an algal mixture under the conditions of example 1, but at a temperature of 60 ^o C and a duration of 3 hours. The strength of the gels of 2% solutions of carrageenan 350 g Valence during the deposition of potassium chloride and 600 g Valence when treated with potassium hydroxide.

 Then, agar was prepared from the algal mixture under the conditions of Example 1.

Example 3. Extract carrageenan under the conditions of example 1, but at a temperature of 70 ^o C and a duration of 2 hours. The strength of the gels of 2% solutions of carrageenan is 360 g by Valence when precipitated with potassium chloride and 700 g by Valence when treated with potassium hydroxide.

The agar is then extracted from the algal mixture under the conditions of example
The proposed method allows to exclude such a time-consuming process of sorting the algal mixture when producing agar or carrageenan, to obtain carrageenan and agar for completely independent jelly-forming agents by sequential extraction of a mixture of chondrus and anfelia algae, not inferior in organoleptic and physico-chemical indicators to the norms of the standard for food and agar food carrageenan .

Claims (1)

A method of producing gelatinizing agents from a mixture of seaweed red algae, including demineralization of algae, removing pigments, washing in water, extraction of gelatinizing agents, dehydration and drying, characterized in that the gelatinizing agents are extracted in stages, while the carrageenan is first extracted by treating the mixture with water at 60-70 ^{° C.} for 2.0 to 3.0 hours, and agar was extracted from the algal residue.