RU2148588C1 - Method of preparing inulin from jerusalem artichoke tuber - Google Patents

Abstract

FIELD: agriculture, plant technology. SUBSTANCE: invention relates to methods of preparing inulin from inulin-containing raw. Invention describes method of preparing inulin from Jerusalem artichoke (Helianthus tuberosus) tubers involving its crystallization and drying. Jerusalem artichoke tubers are milled and juice is obtained by physical-mechanical separation of water-soluble substances from water-insoluble fibrous components of tubers. Juice is heated to 80-85 C for 1-3 min and protein and colored substances are removed by filtration. Then juice is purified by ultrafiltration, diafiltration and nanofiltration, cleared by treatment with activated carbon, concentrated and inulin is crystallized from obtained solution. Separation of water-soluble substance from water-insoluble fibrous components of tubers is carried out in 5-10 min after the latter milling, not later. EFFECT: increased output and economy of method. 2 ex

Description

 The invention relates to methods for producing inulin from inulin-containing raw materials.

 Inulin is a carbohydrate from the group of polysaccharides that occurs as a reserve product in tubers and roots of plants of the family Asteraceae. Inulin - the polymer of D-fructose is insoluble in cold water, but soluble in hot water, the molecular weight / mol.m./ is 5000-6000 Da with an average mol.m. approximately 5400 Yes.

 High-fructose syrup, crystalline fructose, ethanol and other food products can be obtained from inulin, and it can also be used as a dietary supplement for regulating metabolism in diseases of diabetes mellitus and obesity.

According to a known method for producing inulin, Jerusalem artichoke tubers are crushed, acidified water / pH 5.0 / is added at a ratio of 1: 2 v / v. and treated at 70 ^o C for 30 minutes The mixture is filtered, CaCo ₃ is added to the filtrate with stirring to pH 8-10, then the precipitate is separated by centrifugation. The supernatant containing 10-12% inulin is decolorized with activated carbon and evaporated at 40 ^° C. under vacuum to 50% solids. Inulin is isolated from this solution with ethyl alcohol / 1: 2 vol. /ob./ and dried at 50-60 ^o C in vacuum / 1 /.

However, in this method, the process becomes more expensive due to the use of water, acid and chalk for extraction of inulin. In addition, the coolant is consumed for heating the reaction mass to 70 ^° C. and holding it at this temperature for 30 minutes, as well as for evaporating the water used for the extraction of inulin in the subsequent stages of the process. When using water as an extractant, the inulin concentration in the solution decreases to 10-12%, and the treatment of the inulin-containing solution with chalk to a pH of 8-10 causes an increase in the coloring of the solution.

A known method of producing inulin from Jerusalem artichoke tubers / prototype /, in which inulin is extracted from crushed tubers with an extractant - 25% aqueous solution of 96 ^o ethanol at a ratio of 1: 1 and a temperature of 1-4 ^o C for 10 days. After separation of the precipitate, the supernatant is diluted with distilled water 1: 1 and purified by ultrafiltration and on ion exchangers / 2 /.

 In this method, the process of extracting inulin from crushed Jerusalem artichoke tubers is long and complicated. To ensure the parameters of the extraction process, additional costs for the use of refrigerant are necessary, and a long extraction process for 10 days increases the cost of technology and reduces the specific volume of production from a unit geometric volume of equipment. The use of an aqueous solution of ethanol as an extractant requires additional costs for the organization of fire and explosion-proof production. The use of water at the extraction stage entails an increase in the cost of evaporation of the solution during product cleaning.

 The claimed invention solves the problem of simplifying the technology for producing inulin and improves the productivity and efficiency of the method of producing inulin from Jerusalem artichoke.

This is achieved by the fact that in the method of producing inulin from Jerusalem artichoke tubers, including its crystallization and drying, from crushed Jerusalem artichoke tubers by means of physicomechanical separation of water-soluble substances from water-insoluble fibrous substances of tubers, juice is obtained from which, by heating to a temperature of 80- 85 ^o C for 1-3 minutes and filtering remove protein and colored substances, after which the juice is purified using ultrafiltration, diafiltration and nanofiltration, clarified with activated carbon, they concentrate and inulin crystallize from the resulting solution, and the separation of water-soluble substances from the water-insoluble fibrous substances of the tubers is carried out no later than 5-10 minutes after grinding the latter.

Example No. 1. Jerusalem artichoke tubers after thorough washing and inspection in an amount of 10 kg are crushed by crushing to a particle size of 0.3 - 1 mm. Immediately, within 5 minutes, the separation of juice from the solid fibrous substances of ground Jerusalem artichoke by gravity begins from the obtained gruel. After isolation of the juice / I / pulp is squeezed in the press. The resulting juice / II / is connected to gravity juice / I /. Protein substances and colored impurities are removed from the juice by heating to a temperature of 80-85 ^o C for 1-2 minutes. The volume of juice / I + II / is 7300 cm ³ , the solids content / CB / - 21.5%; optical density / OD / - 0.41 with a cell length of 10 mm and a wavelength of light 440 nm. Protein substances and colored compounds are coagulated, part of the coagulant is formed on the surface in the form of a “cap”. Separation of coagulated solid particles from liquid is carried out by filtration. The volume of the filtrate is 5740 cm ³ , the content of CB is 19.5%, OD is 0.11, and the purity is 76.15%. The obtained light yellow filtrate is purified from high molecular weight substances of inulin nature with a mol.m of more than 6500 Da and colloidal dispersed substances by ultrafiltration on hollow fibers. The concentrate after ultrafiltration of the solution is diluted with water in a ratio of 1: 2 vol./about. and diafiltered. Permeates after ultrafiltration and diafiltration are combined. The volume is 5580 cm ³ , the content of CB is 18.8%, and the purity is 87.4%. The permeate is further purified from inorganic impurities and inulin with a mol.m of less than 4,500 Da by nanofiltration, passing it through a semipermeable membrane with a retention threshold of 4,500 Da. Low molecular weight and inorganic impurities pass into the ultrafiltrate, and inulin accumulates in a concentrate that contains 26.8% CB, benignness is 94.3%, and pH is 6.7. Purification of the inulin-containing solution from dyes is carried out with OU-A brand coal, which is added to the solution in an amount of 0.05-0.3% and contacted at a temperature of 50-60 ^o C for 30-40 minutes. Coal is separated by centrifugation. This process can be conducted in dynamic mode. The filtrate is discolored by 70-80%. The bleached solution was evaporated to a 60-65% CB at a temperature of 55-60 ^o C and a vacuum of 150-180 mm RT. Art. Inulin is crystallized at 4 ^° C. from a concentrated solution with a volume of 1,500 cm ³ containing 59.2% CB. The output is 740 g, taking into account the return of the mother liquor. After recrystallization from a water-alcohol solution and drying, 710 g of inulin is obtained.

In the obtained product, analytically determined 96.4% of the main substance / inulin /, rotation angle [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ equal to 37.2 ^o , the moisture content of 5.8%, the content of sulfate ash 0.3%. The permeate is chromatographically homogeneous; one brown spot at the start was detected on the chromatogram. No hydrocarbon impurities in the form of monosugars were found; pH 6.7; lead content 0.06 mg / kg; cadmium 0.02 mg / kg; Cs-137 less than 4.5 bq / kg; Sr-90 21.3 bq / kg; arsenic, mercury and copper are not contained.

Example No. 2. Jerusalem artichoke tubers are thoroughly washed, inspected, and ground in an amount of 10 kg at a grater by abrasion until a “gruel” is obtained, which is centrifuged no later than 10 minutes with a separation factor of at least 6600. The resulting juice is sent for cleaning from protein and colloidal particles, and pulp - for disposal. As a result of centrifugation, 7100 cm ^{3 of} juice was obtained with a CB content of 21.2%, with an optical density of 0.39 at a cell length of 10 mm and a wavelength of 440 nm. The juice is heated to 85 ^o C and maintained at this temperature for up to 3 minutes Coagulated protein substances and colloidal particles are separated from the liquid by centrifugation with a separation factor of at least 6600. The volume of the centrate is 5700 cm ³ , the SW content is 19.3%, the OD is 0.09%, and the benignness is 76.3%. Purification of the obtained centrate is carried out according to the scheme described in Example No. 1. From in a concentrated solution of 1750 cm ³ with a content of 56.5% CB, inulin is crystallized at a temperature of 8 ^o C for 12 to 18 hours, and then the inulin is separated from the mother liquor by centrifugation at a factor separation equal to 6600. Get 710 g of wet inulin, taking into account the returns of the mother liquor. The output of inulin after drying is 450 g. The resulting product has the following physicochemical parameters: inulin content of 97.2%, rotation angle of 38.5 ^o , moisture content of 5.9%, sulfate ash content of 0.3%. The preparation is chromatographically homogeneous; no carbohydrate impurities were detected.

Sources of information:
1. Abelyan V.A. Obtaining and using immobilized enzymes and microorganism cells. Publishing House of the Academy of Sciences of the ArmSSR, Yerevan, 1989 - 319 p. / p. 348/.

 2. RF patent N 2001621, A 61 K 35/78, 1993, BI N 39-40.

Claims (1)

A method of producing inulin from Jerusalem artichoke tubers, including its crystallization and drying, characterized in that from the crushed Jerusalem artichoke tubers using physicomechanical separation of water-soluble substances from water-insoluble fibrous substances of tubers, juice is obtained from which, by heating to 80 - 85 ^o С during 1 to 3 minutes and filtering remove protein and colored substances, after which the juice is purified using ultrafiltration, diafiltration and nanofiltration, clarified with activated carbon, concentrated and inulin crystallizes from the resulting solution, and the separation of water-soluble substances from water-insoluble fibrous substances of tubers is carried out no later than 5 to 10 minutes after grinding the latter.