Potential of bagasse obtained using hydrothermal liquefaction pre-treatment as a natural emulsifier

Bagasse, a by-product from raw sugar factories, is conventionally burned for energy production. In this study, bagasse extracts from hydrothermal liquefaction (HTL) treatment (160 °C, 1 MPa and 30 min) with a carbohydrate content of 510.3 mg g^?1 and 0.5 mg g^?1 of total phenols were applied as emulsifiers in oil-in-water (O/W) emulsions. Bagasse extracts from HTL (0.5–4 wt%) lowered the interfacial tension between oil–water interphase from 19.8 to 14.0 mN m^?1, owing possibly to the surface-active hydrophilic carbohydrate-hydrophobic lignin complexes in the extracts (lignin content: 7.1% w/w). Emulsions stabilised by bagasse extracts from HTL with average droplet size, d_av of 0.79 μm were comparable with gum arabic (GA), d_av of 2.24 μm after 11 days at 25 °C. Bagasse extracts containing biopolymers have the potential for industrial applications involving emulsion systems; therefore, HTL treatment of bagasse without any solvents can be regarded as an effective tool for producing natural emulsifiers.