Improving the freeze–thaw stability of emulsions via combining phosphatidylcholine and modified starch: A combined experimental and computational study

Abstract

SummaryPhosphatidylcholine (PC)‐coated emulsion was unstable during the freezing process. This study aimed to investigate the influences of octenyl succinic anhydride modified starch (OSAS) to PC weight ratios on the properties of the OSAS–PC complex and freeze–thaw stability of oil‐in‐water (O/W) emulsions. The results of molecular dynamics (MD) simulation indicated that electrostatic interaction was dominant in the complex. When OSAS/PC weight ratios were 5:5, 6:4, and 3:7, the complex showed a relatively low interfacial tension, high interfacial layer thickness, and high apparent viscosity at low shear rate. Z‐average diameter in emulsions increased from 175.8 to 270.0 nm and zeta‐potential increased from –49.2 to –29.7 mV, when OSAS/PC weight ratio varied from 0:10 to 7:3. OSAS–PC complex in weight ratios of 3:7 and 5:5 remarkably improved the freeze–thaw stability of emulsions (no creaming and aggregates), which may be related to a thick and dense interfacial layer. These findings indicated that the freeze–thaw stability of PC‐stabilised emulsions could be improved by OSAS with low levels.