Octenyl succinate starch as a hydrogelator and emulsifier for the fabrication of innovative bigels

The present study investigated the use of octenyl succinic anhydride (OSA)-modified corn starch as a novel hydrogelator in bigel formulations, containing oleogel (beeswax and canola oil) and hydrogel. OSA starch showed better swelling power than native starch, resulting in enhanced textural properties and improved water retention in the formulated bigels. FTIR confirmed the formation of ester bonds and DSC analysis revealed reduced melting enthalpy (from 20.0 to 16.8 J/g), indicating improved thermal properties. Pasting properties of OSA starch showed higher peak viscosity (PV = 4636 ± 190 cP), lower peak temperature (PT = 64.8 ± 1.9 °C), and higher degree of breakdown (BV = 2775 ± 40 cP) and final viscosity (FV = 4445 ± 132 cP) compared to native starch (PV = 3852 ± 62 cP, PT = 70.1 ± 2.1 °C, BV = 2310 ± 128 cP, and FV = 4332 ± 69 cP). The rheological properties of hydrogels from both native and OSA starch also demonstrated viscoelastic solid behavior similar to weak gels. In bigel formulations, fluorescence microscopy demonstrated that OSA starch improved phase distribution, reduced droplet size, and enhanced structural stability. Bigel containing 75 % OSA starch hydrogel showed superior stability, rheological performance, and resistance to oil loss compared to others, suggesting an extended shelf life and improved consumer acceptance as fat replacer bigels. DSC results indicated that bigels with a 50:50 ratio of native and OSA starch hydrogels exhibited the highest onset and peak temperatures (94.9 °C and 91.8 °C, respectively) and enthalpy values (386 and 671 J/g, respectively). The rheological analysis confirmed solid-like elasticity (G' > G″) for all bigels. The thermal and rheological improvements enhance the stability and texture of bigels, and make them promising candidates for various applications, including fat replacement in the food industry and as carriers for active ingredient delivery and controlled drug release in biomedical fields.