ABSTRACT
Surfactants are used to reduce surface and interfacial tension to form emulsions. Polysaccharides such as Porang Glucomannan (PG) with high viscosity can be used as surfactants. This research aimed to optimize the concentration of sodium carbonate (Na2CO3) and octenyl succinic anhydride (OSA) in modifying PG using a microwave. The optimization process is carried out using response surface methodology (RSM) with a two-factor central composite design (CCD), namely concentration of Na2CO3 (0.17-5.834%) and OSA (2.17-7.83%). The result showed that the concentration of Na2CO3 and OSA strongly influences emulsion capacity and stability. The optimum conditions that resulted in the highest emulsion capacity and stability were obtained at concentrations of Na2CO3 and OSA which were 2.25% and 6.19%, respectively. Degree of Substitution (DS), FTIR analysis, contact angle, and increased viscosity confirmed that OSA substitution occurred in PG. The characteristics of OSA-modified porang glucomannan (PGOS) such as: emulsion capacity and stability, Degree of Substitution (DS), contact angle, and viscosity increased to 34.6% and 32.5%, 1.02%, 92o, 5720 cP, respectively. FT-IR analysis confirmed the presence of OSA substitution at 1734 cm-1. PGOS can be used as a surfactant or gelator in oleogel production.
