Formulation and characterization of O/W emulsions stabilized using octenyl succinic anhydride modified kudzu starch

Abstract

Kudzu starch esterified with octenyl succinic anhydride (OSA) was used as a food-grade emulsifier to formulate O/W emulsions. In addition, the difference between the physicochemical properties and emulsifying ability of native kudzu starch and those of OSA-modified kudzu starch was investigated. Granules of the OSA-modified kudzu starches increased in size after gelatinization. The interfacial tension between soybean oil and gelatinized OSA-modified kudzu starch was lower than that of kudzu starch. The droplet size of O/W emulsions decreased to 186 nm at 100 MPa after three passes. The emulsions stabilized using gelatinized OSA-modified kudzu starch were less stable when exposed to different ionic strengths (100 mM to 500 mM NaCl), than when exposed to different pH levels (2–8). The results of oil droplet size and confocal laser scanning microscopy analysis indicated that emulsions containing 2–5% OSA-modified kudzu starch remained stable at room temperature for 30 days.

Keywords Emulsions, Octenyl succinic anhydride (OSA), Kudzu