Laccase enzyme

Laccase enzyme (13.6 U/mg) from Trametes versicolor was obtained from Sigma Aldrich. All chemicals were analytical grade and were purchased from Sigma. Shewanella oneidensis MR1 strain 14063 was purchased from NCIMB (UK). The Fe-N/C catalyst was obtained from Dr. J. Masa from Ruhr-University Bochum in Germany.

The main materials used to prepare the polysaccharide-protein conjugate emulsifiers, and appropriate reference samples, were sugar beet pectin (Herbstreith & Fox KG, Neuenbürg, Germany) sodium caseinate, citric acid monohydrate and sodium citrate dihydrate for the preparation of citrate buffers (pH 4 and pH 5), hydrochloric acid and sodium hydroxide to adjust the pH with 1 M solutions, sodium azide as antimicrobial (purchased from Fisher Scientific, Loughborough, UK), ferulic acid, potassium bromide, syringe filters (0.45 µm, ø 15mm, Whatman GE Healthcare) and laccase enzyme (purchased from Sigma-Aldrich, Gillingham, UK). The laccase activity was reported by the supplier as 0.87 units per mg (AU) of the enzyme. Deionized water (electrical conductivity < 2 µS cm⁻¹) produced on-site was used throughout.