β-Cyclodextrin (β-CD) was modified using octenyl succinic anhydride (OSA) to introduce amphiphilic groups (hydrophilic carboxyl and lipophilic octenyl chains) by esterification under alkaline conditions. The FT-IR results indicated that the OSA-modified β-CD (OCD) showed new absorption peaks of an ester bond and a carboxylate (RCOO-) at 1724 and 1570 cm-1, respectively, confirming the successful preparation of OCD. Then the embedding effects of β-CD and OCD on β-carotene and the emulsifying and antioxidant properties of their inclusion complexes were evaluated. The results of XRD showed that the β-CD (or OCD)/β-carotene inclusion complexes were converted from a cage-type structure to a channel-type structure. AFM and SEM showed that the crystal characteristics and surface morphologies of the inclusion complexes were different from those of the physical mixture. The emulsion stabilized by OCD exhibited smaller droplet sizes and larger zeta-potentials than that stabilized by β-CD. In addition, the inclusion complexes-prepared emulsion exhibited lower POV values and TBARS contents than did the physical mixture. OCD/β-carotene inclusion complexes can improve the physical and oxidative stability of the emulsion, which is of great significance to the food industry.
Keywords: Pickering emulsion; octenyl succinic anhydride; oxidative stability; physical stability; β-carotene; β-cyclodextrin.