How Is Food Grade Xanthan Gum Produced?
2026-04-13 10:16:18
Food-grade xanthan gum is manufactured via a controlled aerobic fermentation process using the non-pathogenic bacterium Xanthomonas campestris,followed by purification,recovery,drying,and milling to meet strict food safety standards(FDA 21 CFR 172.695,EU E415,GB 1886.41).
1.Strain Selection&Inoculum Development
Strain:Pure,food-grade Xanthomonas campestris(ATCC 13951 or equivalent industrial strain).
Seed culture:Cultivated through shake flasks and seed fermenters under controlled conditions(28–30°C,pH 6.5–7.0,sterile aeration)to produce a high-viability inoculum.
2.Fermentation Medium Preparation
Sterile,food-safe formulation:
Carbon source:Glucose,corn syrup,sucrose,or molasses(2–5%).
Nitrogen:Yeast extract,corn steep liquor,or soy protein.
Minerals:KH₂PO₄,MgSO₄,calcium salts,and trace elements.
pH control:Maintained at 5.5–7.0 with NaOH or HCl.
3.Main Fermentation(Core Process)
Conducted in large stainless-steel fermenters.
Parameters:28–30°C,60–72 hours,continuous sterile aeration and agitation.
The bacteria secrete extracellular polysaccharide(xanthan gum),drastically increasing broth viscosity.
Fermentation ends when residual sugar<0.2%.
4.Broth Treatment&Cell Removal
Pasteurization:Heating to 80–90°C to inactivate bacteria.
Dilution:Reduced viscosity for efficient processing.
Clarification:Centrifugation or filtration to remove bacterial cells.
5.Precipitation&Recovery
Alcohol precipitation:Food-grade ethanol or isopropyl alcohol(2:1 ratio)is added to precipitate xanthan gum as fibrous solids.
Separation:Centrifugation or filtration to collect wet gum cake.
6.Purification&Washing
Washing with alcohol–water solutions to remove residual sugars,proteins,salts,and pigments.
Dewatering:Mechanical pressing to reduce solvent and moisture.
Clear grade:Additional activated carbon decolorization and ultrafiltration for high transparency.
7.Drying&Milling
Gentle drying(flash/rotary/spray dryer)at<60°C to avoid polymer degradation.
Final moisture:8–12%.
Milled to fine powder(80–200 mesh)and blended for consistent viscosity.
8.Quality Control&Packaging
Testing:Viscosity(1%solution),ash(<10%),protein(<7%),moisture(<13%),heavy metals,and microbiological limits(Salmonella/E.coli negative).
Packed in food-grade polyethylene-lined bags/drums,stored dry and cool.
References
GB/T 7714
García-Ochoa F,Gómez E,Santos V E,et al.Xanthan gum:production,recovery,and properties[J].Biotechnology Advances,2000,18(6):495-513.
MLA
García-Ochoa,Félix,et al."Xanthan Gum:Production,Recovery,and Properties."Biotechnology Advances,vol.18,no.6,2000,pp.495–513.
APA
García-Ochoa,F.,Gómez,E.,Santos,V.E.,&Casas,J.A.(2000).Xanthan gum:Production,recovery,and properties.Biotechnology Advances,18(6),495–513.
