Fermentation produced gums
- Beta-Glucan (1,3/1,6-beta-D-glucan) is an insoluble gum from baker's yeast and is used as a dietary supplement.
- Curdlan Gum (beta-1,3-glucan polymer) is produced by fermentation of a carbohydrate solution with Alcaligenes faecalis var. myxogenes. The fermented product can form a gel when heated in a water suspension.
- Gellan Gum is produced by fermentation of various carbohydrates with Sphingomonas elodea (previously known as Pseudomonas elodea). The gums are very effective in gelling various prod-ucts and is used in confectionery, dairy products, jelly desserts, and several other food products. Several variations have been developed. Some of the final products can be spray dried. Gellan gum is also made by fermentation of a glucose or a glucose / lactose mix with Sphingomonas paucimobilis and the gellan gum was recovered by precipitation with ethanol.
- Rhamsan Gum is produced by fermentation of a carbohydrate solution by Alcaligens strain (ATCC 31961). It is very similar to the gellan gum structure but carries a disaccharide sidechain. Solutions of the gum at low concentration has a very high viscosity at low shear rates.
- Welan Gum is produced by a carefully controlled aerobic fermentation of a carbohydrate solution by Alcaligenes strain (ATCC 31555). It is very similar to the gellan structure, but carries sidechains of L-mannose or L-rhamnose. The gum has similar properties to xanthan gum, but has increased viscosity at low shear rate and improved thermal stability.
- Xanthan Gum is produced by fermentation of carbohydrate solutions by Xanthomonas campes-tris and a wide variety of properties are obtained by controlling the functional groups on the side chains of the xanthan gum. The xanthan gums normally creates high viscosities at low concentrations, but are still easy pump able. After the fermentation the xanthan gum is recovered by precipitation with isopropyl alcohol.
Gums from seeds and corn
- Guar Gum (galactomannans) is made from the seeds kernel from the guar plant Cyamopsis tetragonoloba. The gum is extracted from the guar been and is water soluble. For the production is used extraction, separation and concentration. The gum is not self-gelling, but addition of calcium or borax will cause it to gel. Guar gum is very important in the commercial food industry and several other industries. The guar gum can be made as powders by milling of pre-dried flakes or by spray drying solutions and emulsions.
- Konjac Gum (glucomannans) is made from the corm of the Amorphopha llus konjac plant by m ixing the konnyaku flour wi th water and is mainly used in the Chinese and Japanese kitchen. The mix of flour and water is boiled and cooled to solidify. The konjac gum has a high content of glucomannans, which is used as a dietary fibre.
- Locust Bean Gum / Carob gum (galactomannans) is made from seeds from the locust bean tree or the European carob tree. The seeds are milled, sifted and extracted with water. The gum is partially soluble in cold water and a part is not giving a low viscosity, but by heating for at approx. 80°C for 2-5 minutes the solution/suspension is getting a high viscosity.
- Psyllium Seed Gum is made from the coat of the seeds from Plantago ovata. The gum is ex-tracted with boiling water and the extract is cleaned by filtration. It forms a viscous solution at 1 %TS and a clear gelatinous mass at higher concentration.
- Quince Seed Gum is extracted from the seeds in the fruits of the quince trees Cydoni a vulg aris or Cydonia oblongs. The extraction is made with cold or hot water and cleaned by filtration. It is recovered by precipitation with alcohol. Creates high viscous solutions at up to 1.5%TS by heating. It is used in cosmetics and pharmaceutical preparations.
- Tamarind Gum is made from the seed kernels from the tamarind tree Tamarindus indica. The tamarind kernel powder is insoluble in cold water, but by heating it forms thick viscous colloidal dispersions at 2-3%TS. Drying of this dispersion forms elastic films. The gum forms gels over a wide pH-rang and high concentrations of sucrose and is a possible substitute for pectin.
- Tara Gum (galactomannans) is made from the seeds from the Caesalpinia spinosa bush. The gum is cold water soluble and obtains high viscosity be heating.
- Arabinogalactan is made from the larch tree and is a cold- water and hot-water soluble gum, which is stable over a wide pH-range. It has a high content of fibres and still a low viscosity.
- Beta-Glucan (1,3/1.4-beta-D-glucan) is found in the bran of especially oat and barley and are found to have very good properties as soluble fibres.
- Pectins (galaturonic acid and galaturonic acid methyl ester) are mainly made is commercial scale from citrus peel, and apple pomace. The production and purification is based on the solubility in warm water and insolubility in polar organic solvent. During the production procedures are also used separators. Spray drying of a warm solution before alcohol precipitation could be possible, but one purification step would be missing.
- Chircle Gum is made from the Manilkara chicle tree and has mainly been used as a chewing gum. The sap is collected from cuts in the tree trunk and boiled until the right thickness is obtained. It has no big commercial use today. It might be possible to spray dry.
- Dammar Gum is obtained from the Dipterocarpaceae family trees (the genera Shorea, Balan o-carpus, or Hopea). Part or the production is collected from sap from the tree trunk and some in fossilized form from the ground. The sap is boiled until the right thickness is obtained.
- Gum Arabic is made from an exudate from the Arcacia senegal and Acacia seyal trees, it is soluble in cold water and will increase in solubility by heating. Some final products are dried like flakes and milled and some are spray dried.
- Gum Ghatti is made from the Anogeissus latifolia tree. The sap is collected from natural exuda-tions or extra incisions. The gum is grinded to a fine powder. Powder dispersed in water form gels with viscosity intermediate with gum Arabic and gum karaya.
- Gum Tragacanth is made from the sap from i n cisions in the stem of the Astragalus gummifer. The sap is cleaned and boiled to obtain the right thickness is obtained. The gum is almost insoluble in water, but swells in it to form a stiff gel.
- Karaya Gum is made from the dried exudate from the Sterculia tree, it is not soluble in water, but forms a gel, which already at 3-4%TS is a heavy gel. Higher concentrations will solubilise by cooking under steam pressure.
- Mastic Resin is collected from the mastic shrub Pistacia lentiscus by making incisions in the branches and letting the resin drop down to the ground where it is collected. The resin is purified and used for food, confectionary and pharmaceutical preparation.
- Agar-Agar Gum (galactans with little half-eater sulphate) is made from different species of red algae (Gelidium, Gracilar ia,a n d Eucheuma, class Rhodophyceae) by extraction with boiling water. The extract is separated by filt r ation and centrifugation, purified, concentrated and solidified by cooling. Dried products can be obtained by belt drying, drum drying and spray drying. The spray drying is mainly for the low viscous solutions. Several new products have been developed by changing the composition of the natural extracts.
- Alginic Acid and Alginates (mixed polymers of mannuronic acid and guluronic acid) are made from brown sea weeds (Macrocystis pyrifera, Ascophyllum nodosum and various types of Laminaria). Alginic acid is insoluble in water, but soluble in alkaline. In the production process the macerated seaweeds are washed with diluted mineral acid for removal of minerals, fucoidine, mannitol and other soluble ingredients. The washed product is then made alkaline to form the water soluble alginates.
This makes it possible to separate insoluble ingredients like cellulosic and proteinic components by filtration, floating and sedimentation. The alginic acid is then precipated by a mineral acid, collected washed and dried on belt dryer or drum dryer. The alginic acid is then dissolved by alkaline and various products are made, and dried by belt drying, drum drying or spray drying.
- Carrageenans (galactans with half-eater sulphate) are made from red seaweeds. At least five different structures with different properties are identified (the iota-, kappa., lambda-, mu-, and nucarrageenan). The extraction and purification is mainly based on the properties that carrageenans are soluble in hot water and insoluble in polar organic solvents. After washing the seaweeds they are crushed under warm, alkaline conditions and extracted.
The warm extract is filtered and the carrageenans are recovered by alcohol precipitation. This also functions as a purification process. The precipitate is pressed, washed with alcohol and dried under vacuum. The dried product is milled to the final powder product. The extract could also be spray dried instead of precipitated, but then a purification step.