Title: Structures of Octenylsuccinylated Starches: Effects on Emulsions Containing ␤-carotene Structures of Octenylsuccinylated Starches: Effects on Emulsions Containing Β-carotene. 2

16 Starches with different amylopectin contents and different molecular sizes prepared 17 using acid hydrolysis were hydrophobically modified using octenylsuccinic anhydride 18 (OSA). The OSA-modified starches were used as surfactants to stabilize emulsions of 19 β-carotene and canola oil dispersed in water. The objective of this study is to 20 investigate the relationship between starch molecular structure and the chemical 21 stability of the emulsified β-carotene, as well as the colloidal stability of emulsion 22 droplets during storage. The oil droplet size in emulsions was smaller when starch had 23 (a) lower hydrodynamic volume (Vh) and (b) higher amylopectin content. The 24 oxidative stability of β-carotene was similar across samples, with higher results at 25 increased amylopectin content but higher Vh. Steric hindrance to coalescence provided 26 by adsorbed OSA-modified starches appears to be improved by more rigid molecules 27 of higher degree of branching. 28