CN113373190B - Method for preparing galactomannan from semen Trigonellae - Google Patents

Abstract

The invention discloses a method for preparing galactomannan from fenugreek. The method comprises the steps of firstly peeling fenugreek and lima beans, then adding water for tempering, mixing and crushing; then sanding the mixture in a sanding machine; adding water, mixing well to obtain water solution, adding mannase and galactosidase, and hydrolyzing to obtain enzymatic hydrolysate; finally, inactivating the enzymolysis liquid, cooling to room temperature, filtering, decolorizing, concentrating to obtain syrup, and vacuum drying to obtain galactomannan. The invention adopts fenugreek and lima beans as extraction raw materials to prepare the galactomannan, compared with the galactomannan obtained by singly adopting the fenugreek, the galactomannan has better solubility and higher viscosity, and part of the galactomannan is decomposed into mannan-oligosaccharide by adopting the micro-fermentation of mannase and galactosidase, so that the prepared galactomannan is easier to be absorbed and utilized by human bodies.

Description

A method for preparing galactomannan from fenugreek

technical field

The invention belongs to the technical field of natural food additives, in particular to a method for preparing galactomannan from fenugreek.

Background technique

Galactomannan is a polysaccharide consisting of a mannose backbone and galactose side groups, which are linked to α- A polysaccharide of D-galactose, that is, 1-6-linked α-D-galactopyranose. Galactomannan is derived from fenugreek gum, guar gum, carob gum and tara gum, and galactomannan from different plant sources has different degrees of branching.

Fenugreek (Latin scientific name: Trigonella foenum-graecum L.) is the common name of fenugreek, a plant of the genus Fenugreek in the family Fabaceae. Annual herbaceous plant, 30-80 cm high, with well-developed root system, erect stem, pinnate three compound leaves, flat petiole, flowering period from April to July, and fruiting period from July to September. Fenugreek can be used as a raw material for the preparation of galactomannan, and patent 02138257.3 discloses a production method for rapid dispersion and instant galactomannan gum. It is made from high-quality industrial-grade galactomannan film (fenugreek film) through hydration, drying, milling, grading, soaking in edible alcohol, centrifugal precipitation, and vacuum drying. The total dissolution time of the prepared galactomannan gum is 25min, and the viscosity of 1% glue reaches 350mPa.s (170s ^-1 ), although the solubility is somewhat higher than that of galactomannan gum derived from other plant species. Improve, but still can not meet people's requirements for fast dissolution and increased viscosity.

Contents of the invention

The object of the present invention is to provide a method for preparing galactomannan from fenugreek.

A method for preparing galactomannan from fenugreek, carried out according to the following steps:

(1) Peel the fenugreek and gourd beans, then add 2-4% water for conditioning for 6-12 minutes;

(2) Mix and crush the fenugreek after peeling and conditioning, and pass through a 20-30 mesh sieve; then enter a sand mill for sand milling, and pass through a 50-80 mesh sieve;

(3) adding water 3-10 times the mass of the material in step (2), mixing evenly to make an aqueous solution, adding mannanase and galactosidase, hydrolyzing to make an enzymatic solution;

(4) Inactivate the enzymolysis solution prepared in step (3) in a boiling water bath and cool to room temperature, filter, decolorize, and concentrate to obtain syrup;

(5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan.

The dosage-mass ratio of the fenugreek and the gourd beans is (2-5):1.

The added amount of the mannanase is 100-200U per gram of the mixed material in step (2).

The added amount of the galactosidase is 50-100 U per gram of the mixed material in step (2).

The hydrolysis temperature in step (3) is 30-50°C, and the hydrolysis time is 1-5h.

The decolorization adopts active carbon decolorization.

The vacuum drying temperature is 55-75° C., and the vacuum degree is 0.05-0.1 MPa.

Beneficial effects of the present invention: the present invention adopts fenugreek and gourd bean as extraction raw materials to prepare galactomannan, which has better solubility and higher viscosity than galactomannan obtained by using fenugreek alone. Enzyme and galactosidase micro-fermentation, part of the galactomannan decomposed into mannan oligosaccharides, making the prepared galactomannan easier to be absorbed and utilized by the human body.

Description of drawings

Figure 1 shows the time for the sample to dissolve in water to reach the maximum viscosity after co-extraction of fenugreek and other plant seeds.

Figure 2 shows the viscosity of samples after co-extraction of fenugreek and other plant seeds.

Figure 3 shows the time for the samples to dissolve in water and reach the maximum viscosity after co-extraction of different mass ratios of fenugreek and gourd beans.

Figure 4 shows the viscosity of samples after co-extraction of fenugreek and gourd beans in different mass ratios.

Detailed ways

In order to facilitate the understanding of the present invention, the following will describe the present invention more fully. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Example 1

A method for preparing galactomannan from fenugreek, carried out according to the following steps:

(1) Peel the fenugreek, then add 3% water for conditioning for 10 minutes;

(2) Broken fenugreek after peeling and tempering, and crossed a 25-mesh sieve; then entered a sand mill for sand milling, and crossed a 60-mesh sieve;

(3) Add water with 5 times the mass of the material in step (2), mix uniformly to make an aqueous solution, add mannanase and galactosidase, and hydrolyze to make an enzymatic solution; the amount of mannanase added It is 150U of the mixed material per gram of step (2); the addition of the galactosidase is 80U of the mixed material of per gram of step (2); the temperature of the hydrolysis is 45°C, and the hydrolysis time is 3h;

(4) After inactivating the enzymolysis solution prepared in step (3) in a boiling water bath, cool to room temperature, filter, decolorize with activated carbon, and concentrate to obtain syrup;

(5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan; the vacuum drying temperature is 60° C., and the vacuum degree is 0.08 MPa.

Configure a sample solution with a concentration of 1%; measure the time for the sample to dissolve in water to reach the maximum viscosity. The standard for reaching the maximum viscosity is that the solution is a uniform solution visually, without bubbles and agglomerates. The glass rod has a sense of resistance when stirred, and it adheres after stirring. It does not fall within 5s; the time to dissolve and reach the maximum viscosity is measured to be 38min; the viscosity is measured to be 352mPa.s (170s ^-1 ) by a capillary viscometer.

Example 2

In order to improve the viscosity of galactomannan and reduce the time to dissolve in water to reach the maximum viscosity, the inventor tried to use other plant seeds containing galactomannan and fenugreek to extract together, the mass ratio was 1:1, the experimental method Same as Example 1, the selected plants include sea red bean, cassia seed, gemu, gourd bean, pepper hemp, pig's dung bean, winged viburnum, and tianjing; a sample solution with a concentration of 1% is prepared, and the sample is dissolved in water to reach the maximum viscosity. The time and viscosity, measurement results are shown in Fig. 1 and Fig. 2.

It can be seen from Fig. 1 and Fig. 2 that the sample after co-extraction of fenugreek and gourd bean dissolves in water and reaches the maximum viscosity in the shortest time, and the viscosity is the largest.

Example 3 Extraction Proportion Optimization

Fenugreek and gourd bean were selected as raw materials for co-extraction, the optimal dosage ratio of fenugreek and gourd bean was explored, and the dosage-mass ratio of fenugreek and gourd bean was set as 1:3, 1:2, 1:1, 2:1, 3: 1, 4:1, 5:1, 6:1, the experimental method is the same as in Example 1; after the extraction operation is completed, a sample solution with a concentration of 1% is prepared, and the time and viscosity of the sample dissolved in water to reach the maximum viscosity are measured, and the results are shown in Figures 3 and 4.

It can be seen from Figure 3 and Figure 4 that when the mass ratio of fenugreek to gourd bean is 3:1, the time for the sample to dissolve in water to reach the maximum viscosity is the shortest, and the viscosity is the largest.

Example 4

A method for preparing galactomannan from fenugreek, carried out according to the following steps:

(1) Peel the fenugreek and gourd beans, then add 3% water for conditioning for 10 minutes;

(2) Break the peeled and tempered fenugreek and gourd beans respectively, mix according to the mass ratio of 3:1, and pass through a 25-mesh sieve; then enter the sand mill for sand grinding, and pass through a 60-mesh sieve;

(3) Add water with 5 times the mass of the material in step (2), mix uniformly to make an aqueous solution, add mannanase and galactosidase, and hydrolyze to make an enzymatic solution; the amount of mannanase added It is 150U of the mixed material per gram of step (2); the addition of the galactosidase is 80U of the mixed material of per gram of step (2); the temperature of the hydrolysis is 45°C, and the hydrolysis time is 3h;

(4) After inactivating the enzymolysis solution prepared in step (3) in a boiling water bath, cool to room temperature, filter, decolorize with activated carbon, and concentrate to obtain syrup;

(5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan; the vacuum drying temperature is 60° C., and the vacuum degree is 0.08 MPa.

Example 5

A method for preparing galactomannan from fenugreek, carried out according to the following steps:

(1) Peel the fenugreek and gourd beans, then add 3% water for conditioning for 10 minutes;

(2) Break the peeled and tempered fenugreek and gourd beans respectively, mix them evenly according to the mass ratio of 4:1, and pass through a 25-mesh sieve; then enter the sand mill for sand grinding, and pass through a 60-mesh sieve;

(3) Add water with 6 times the mass of the material in step (2), mix uniformly to make an aqueous solution, add mannanase and galactosidase, and hydrolyze to make an enzymatic solution; the amount of mannanase added It is 200U of the mixed material per gram of step (2); the addition of the galactosidase is 100U of the mixed material of per gram of step (2); the temperature of the hydrolysis is 40°C, and the hydrolysis time is 3h;

(4) After inactivating the enzymolysis solution prepared in step (3) in a boiling water bath, cool to room temperature, filter, decolorize with activated carbon, and concentrate to obtain syrup;

(5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan; the vacuum drying temperature is 60° C., and the vacuum degree is 0.06 MPa.

Example 6

A method for preparing galactomannan from fenugreek, carried out according to the following steps:

(1) Peel the fenugreek and gourd beans, then add 3% water for conditioning for 10 minutes;

(2) Break the peeled and tempered fenugreek and gourd beans respectively, mix them evenly according to the mass ratio of 2:1, and pass through a 25-mesh sieve; then enter the sand mill for sand grinding, and pass through a 60-mesh sieve;

(3) Add water with 4 times the mass of the material in step (2), mix uniformly to make an aqueous solution, add mannanase and galactosidase, and hydrolyze to make an enzymatic solution; the amount of mannanase added It is 100 U of the mixed material per gram of step (2); the addition amount of the galactosidase is 60 U of the mixed material of per gram of step (2); the temperature of the hydrolysis is 50°C, and the hydrolysis time is 2h;

(4) After inactivating the enzymolysis solution prepared in step (3) in a boiling water bath, cool to room temperature, filter, decolorize with activated carbon, and concentrate to obtain syrup;

(5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan; the vacuum drying temperature is 60° C., and the vacuum degree is 0.05 MPa.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (6)

1. a method for preparing galactomannan from Fenugreek, characterized in that, proceed according to the following steps: (1) Peel the fenugreek and gourd beans, then add 2-4% water for conditioning for 6-12 minutes; (2) Mix and crush the fenugreek after peeling and conditioning, and pass through a 20-30 mesh sieve; then enter a sand mill for sand milling, and pass through a 50-80 mesh sieve; (3) adding water 3-10 times the mass of the material in step (2), mixing evenly to make an aqueous solution, adding mannanase and galactosidase, hydrolyzing to make an enzymatic solution; (4) Inactivate the enzymolysis solution prepared in step (3) in a boiling water bath and cool to room temperature, filter, decolorize, and concentrate to obtain syrup; (5) Vacuum drying the syrup prepared in step (4) to obtain galactomannan; The dosage-mass ratio of the fenugreek and the gourd beans is (2-5):1. 2. The method for preparing galactomannan from Fenugreek according to claim 1, characterized in that the amount of mannanase added is 100-200 U per gram of the mixed material in step (2). 3. The method for preparing galactomannan from Fenugreek according to claim 1, characterized in that the amount of galactosidase added is 50-100 U per gram of the mixed material in step (2). 4 . The method for preparing galactomannan from Fenugreek according to claim 1 , wherein the hydrolysis temperature in step (3) is 30-50° C., and the hydrolysis time is 1-5 h. 5. The method for preparing galactomannan from Fenugreek according to claim 1, wherein said decolorization adopts active carbon decolorization. 6 . The method for preparing galactomannan from Fenugreek according to claim 1 , wherein the vacuum drying temperature is 55-75° C., and the vacuum degree is 0.05-0.1 MPa.

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