Comparison of physicochemical properties and digestion behaviors of O/W emulsion stabilized by OSA/DDSA-modified high resistant starch

Emulsions stabilized by normal starch-based emulsifier could be easily digested for fat absorption. In this study, a novel design of resistant starch-based emulsifier (RSE) is expected to be a promising strategy in reducing fat digestibility. Waxy corn starch (WCS) was used to prepare RS by pullulanase debranching, and then RS was esterified with different hydrophobic agents of octenyl succinic anhydride (OSA) and dodecenyl succinate anhydride (DDSA) to prepare OSA/DDAS modified RSE (OSA-R and DDSA-R). The structure and emulsification properties of OSA-R and DDSA-R were comprehensively investigated. The results showed that RS content of WCS was increased from 0.17% to 35.52% by pullulanase debranching and then RS contents of OSA-R (37.53%) and DDSA-R (42.18%) could be further increased by OSA/DDSA modifications. Moreover, both OSA-R and DDSA-R stabilized emulsions were stable under neutral and alkaline conditions and were of good quality within 10 days of storage at 4 °C. Compared with OSA-R stabilized emulsion, DDSA-R stabilized emulsion had higher acid stability, CaCl₂ stability and storage stability. Furthermore, in vitro digestion study demonstrated that both OSA-R and DDSA-R stabilized emulsions exhibited strong resistance against digestion. In conclusion, two high resistant starch-based emulsifiers obtained by OSA/DDAS modifications could be used for stabilizing oil-in-water emulsions, which provide important references for the selection of RSE esterification agents and the application of RS in food industry.