Emulsification properties of sugar beet pectin after modification with horseradish peroxidase

Sugar beet pectin (SBP) was enzymatically modified by crosslinking ferulic acid groups using horseradish peroxidase (HRP). The purpose of the modification was to achieve maximum molecular weight while retaining reasonably good solubility of the SBP. Reaction conditions were optimized in terms of pH (5.0-7.0), H2O2 concentration (0.25-1.0 mM) and HRP dose (0.0017-0.0083 U/mL). A maximum molecular weight of 1.86 x 10(6) Da was obtained at pH = 6.5, H2O2 = 1.0 mM and HRP = 0.005 U/mL while also remaining good solubility. The emulsifying properties of the SBPs before and after modification were evaluated. The emulsion prepared using the modified SBP and medium chain triglyceride (MCT) showed improved stability during acceleration test at 60 degrees C for a period of 10 days, in comparison with the emulsion prepared with control SBP. The volume-weighted mean diameter D-4, (3) after 10-day acceleration was 12.1 and 20.6 mu m for emulsions stabilized with modified and control SBPs, respectively. (C) 2014 Elsevier Ltd. All rights reserved.