Method of extraction of a galactomannan gum from alfalfa seeds

A clean label galactomannan gum fraction from alfalfa plants, comprising:

• at least 98% or 99% of the total amount of carbohydrates as galactose and mannose monomers;
• and
• less than 1% of proteins;
• wherein the galactomannan gum fraction is obtainable from a galactomannan gum pellet by a process 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 the polysaccharide gum pellet;
• wherein the alfalfa plants comprise alfalfa seeds;
• and
• wherein the method 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 of 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;
• wherein the galactomannan gum fraction is characterized by a zero-shear viscosity (η0) of at least 1000 mPa·s−1 and an intrinsic viscosity ([η]) of at least 7 dL·g at 1% w/w in deionized water, at pH=7.