Method of extraction of a galactomannan gum from alfalfa seeds

Patent metadata

Field	Value
Publication number	US-12522673-B2
Application number	US-202118164983-A
Country	US
Kind code	B2
Filing date	Aug 3, 2021
Priority date	Aug 5, 2020
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A method of extracting polysaccharides from alfalfa plants, the method comprising the followings steps: milling of the alfalfa plants; addition of a buffer solution to the milled alfalfa plants and separation of the milled plants, thus producing a polysaccharides-composed supernatant and a protein-composed pellet; and precipitation of the polysaccharides in the polysaccharides-composed supernatant; the alfalfa plants comprising alfalfa seeds; and the method comprising the following steps, prior to the milling step: soaking of the alfalfa plants in water so as to swell the alfalfa seeds; mesh filtration of the alfalfa plants comprising the swollen alfalfa seeds; and drying of the alfalfa plants comprising the swollen alfalfa seeds.

First claim

The invention claimed is:

1 . A method of extracting polysaccharides from alfalfa plants, said method comprising the followings steps:
milling of the alfalfa plants; extracting polysaccharides by addition of a buffer solution to the milled alfalfa plants; separating the milled alfalfa plants of the buffer solution, thus producing a polysaccharides-composed supernatant and a protein-composed pellet; and precipitating the polysaccharides in the polysaccharides-composed supernatant so as to produce a polysaccharide gum pellet; wherein the alfalfa plants comprise alfalfa seeds; and wherein the method further comprises the following steps, prior to the milling step: soaking of the alfalfa plants in water so as to swell the alfalfa seeds; mesh filtrating the alfalfa plants comprising the swollen alfalfa seeds; and drying of the alfalfa plants comprising the swollen alfalfa seeds, so as to concentrate galactomannan in the polysaccharide gum pellet.

2 . The method according to claim 1 , wherein the step of precipitation of the polysaccharides is made with at least one organic solvent.

3 . The method according to claim 1 , wherein, after the step of precipitation of the polysaccharides, several sequential-graded precipitations of the polysaccharides, with at least one organic solvent, are carried out, so as to produce the polysaccharide gum pellet that is refined.

4 . The method according to claim 3 , wherein the several sequential-graded precipitations of the polysaccharides with at least one organic solvent are respectively carried out with sequential concentrations of the at least one organic solvent from 50% to 90% in volume in an aqueous solution.

5 . The method according to claim 1 , wherein the alfalfa seeds correspond to at least 90% in weight of the alfalfa plants.

6 . The method according to claim 1 , wherein the step of extraction further comprises adjusting of the pH of the buffer solution to a pH comprised between 3 and 6.

7 . The method according to claim 1 , wherein the soaking of the alfalfa plants in water is carried out at alfalfa plants/water ratios ranging from 1:5 to 1:40, at a temperature comprised between 20° C. and 90° C. for a duration comprised between 20 minutes and 10 hours.

8 . The method according to claim 1 , wherein the method further comprises the following steps, after the step of precipitation of the polysaccharides-composed supernatant:
centrifugating the precipitated polysaccharides so as to produce the polysaccharide gum pellet; and reconstituting the polysaccharides gum pellet in water, forming a dispersed polysaccharide gum pellet, and adjusting the dispersed polysaccharide gum pellet to a pH above 9.

9 . The method according to claim 8 , wherein the method further comprises the following steps, after adjusting the pH of the dispersed polysaccharides gum pellet:
acidification of the dispersed polysaccharide gum pellet to a pH comprised between 3 and 6, then centrifugating the dispersed polysaccharide gum pellet.

10 . The method according to claim 1 , wherein the method further comprises the following steps, after the step of precipitation of the polysaccharides is carried out:
reconstituting in water of the polysaccharide gum pellet; reconstituting a dispersed polysaccharide gum pellet in an acidified water; neutralizating the dispersed polysaccharide gum pellet with an alkali solute; dialysis, ultrafiltration or reverse osmosis of the dispersed polysaccharide gum pellet; and drying of the dispersed polysaccharide gum pellet.

11 . The method according to claim 1 , wherein the protein-composed pellet, obtained after the step of separation of the milled plants, forms an alfalfa seed meal protein concentrate; the alfalfa seed meal protein concentrate being further processed by the following steps:
suspending the alfalfa seed meal protein concentrate into alkaline water, forming a suspension with a pH above 8; and solid-liquid separating the suspension, producing a sediment and a supernatant solution, the sediment forming an alfalfa seed protein flour.

12 . The method according to claim 11 , wherein the supernatant solution produced by the solid-liquid separation of the suspension is further processed by the following steps:
precipitating the supernatant solution at a pH comprised between 3 and 6; centrifugating the supernatant solution, producing at least a precipitate, submitting the precipitate to a dialysis, an ultrafiltration or a reverse osmosis; and drying of the precipitate, thus forming an alfalfa protein isolate.

13 . The method according to claim 1 , wherein adjusting the pH above 8 or 9 is carried out with an alkali solute.

14 . The method according to claim 12 , wherein adjusting the pH between 3 and 6 is carried out with an acid.

15 . The method according to claim 1 , wherein a concentration in weight of galactose and mannose in the polysaccharides gum pellets is at least 80%.

Assignees

• Luxembourg Inst Science & Tech List

Inventors

• Hellebois Thierry
• Soukoulis Christos

Classifications

• C08B37/0003 Primary

  General processes for their isolation or fractionation, e.g. purification or extraction from biomass · CPC title

• A23J1/007

  from leafy vegetables, e.g. alfalfa, clover, grass · CPC title

• A23L33/21

  Addition of substantially indigestible substances, e.g. dietary fibres · CPC title

• A23L29/206

  of vegetable origin · CPC title

• A23L33/105

  Plant extracts, their artificial duplicates or their derivatives · CPC title