title: Electrostatic interactions of cationic lauric arginate with anionic polysaccharides affect antimicrobial activity against spoilage yeasts.
abstract: OBJECTIVE
  To investigate the effect of anionic polysaccharides often used in beverage applications (xanthan and λ-carrageenan) on the antimicrobial efficacy of the cationic surfactant lauric arginate (LAE) against typical spoilage yeasts.
  
  
  RESULTS
  The antimicrobial efficacy of LAE against Saccharomyces cerevisiae, Candida albicans and Zygosaccharomyces bailii in the absence and presence of anionic polysaccharides was assessed by microtitre and macrobroth dilution assays. Combining LAE with either xanthan or λ-carrageenan caused a pronounced decrease in LAE's antimicrobial efficacy, with the minimal inhibitory and lethal concentrations (MIC and MLC) both increasing with increasing polysaccharide concentration. This reduction in antimicrobial efficacy was more pronounced for the addition of λ-carrageenan. To determine the cause of loss of activity, physical properties of solutions were examined. Turbidity and sedimentation measurements indicated that complexes between LAE and anionic polysaccharides had been formed. Electrophoresis measurements showed that complexes had varying electrical charges and dimensions depending on solution composition.
  
  
  CONCLUSIONS
  Results suggest that electrostatic interactions between LAE and anionic polysaccharides play a major role in complex formation and loss of antimicrobial activity.
  
  
  CONCLUSIONS
  Results have important implications for the utilization of LAE as an antimicrobial agent in beverage and food products containing anionic polysaccharides.
authors.affiliation: Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Loeffler
authors.forename: D J
authors.initials: DJ
authors.lastname: McClements
authors.forename: L
authors.initials: L
authors.lastname: McLandsborough
authors.forename: N
authors.initials: N
authors.lastname: Terjung
authors.forename: Y
authors.initials: Y
authors.lastname: Chang
authors.forename: J
authors.initials: J
authors.lastname: Weiss
mesh_terms: D000838:Anions; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001628:Beverages / Q000382:microbiology; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D002351:Carrageenan / Q000737:chemistry / Q000494:pharmacology*; D002412:Cations; D008826:Microbial Sensitivity Tests; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development; D055672:Static Electricity; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*; D020068:Zygosaccharomyces / Q000187:drug effects / Q000254:growth & development
chemical_list: D000838:Anions; D000890:Anti-Infective Agents; D002412:Cations; D011135:Polysaccharides, Bacterial; D013501:Surface-Active Agents; C031371:N(alpha)-lauroylarginine ethyl ester; D002351:Carrageenan; D001120:Arginine; C002563:xanthan gum
keywords: antimicrobials; carrageenan; electrostatic complexation; lauric arginate; spoilage yeasts; xanthan