Effect of octenyl succinic anhydride (OSA) substitution degree on the thermal stability and oral delivery efficiency of β-carotene in emulsions stabilized by high-amylose starch nanocrystals

Abstract

In this study, high-amylose starch nanocrystals (HASNC) were esterified with octenyl succinic anhydride (OSA) at concentrations of 3 %, 6 %, and 9 % (w/w). The study investigates how the degree of OSA substitution (DS) affects the structure of HASNC and how these structural changes influence the thermal stability and oral delivery of β-carotene in HASNC-stabilized emulsions. The results show that as the DS of HASNC increased from 0 to 3.95 %, its emulsifying capacity improved, but its thermal stability decreased. The thermal stability of OSA-HASNC-stabilized emulsions exceeded that of HASNC-stabilized emulsions only when the DS reached 3.03 %. The digestibility resistance of HASNC improved with increasing DS, leading to enhanced stability of HASNC emulsions during the digestion process, and the bioaccessibility of β-carotene increased from 20.3 % to 52.3 %. This study provides valuable insights into the design of emulsions with enhanced thermal stability and effective oral delivery of lipophilic bioactive compounds.