Spice aldehydes improve emulsification stability of β-carotene by Schiff base reaction binding sodium caseinate as emulsion surface stabilizer

Cinnamaldehyde (CA), P-Anisaldehyde (PAA), N-heptanal (NHA) and Citronellal (CNA) were used to modify sodium caseinate (SC) as emulsifiers to stabilize β-carotene emulsion, and the binding mechanism of SC and spice aldehyde (SA) was discussed. The results showed that the binding of SA and SC was mainly driven by non-covalent interaction, especially hydrogen bonding. It was also found that CA may form covalent bond with SC through Schiff base reaction. Moreover, the combination of SA altered the structure of SC, enhanced its surface hydrophobicity, and improved its emulsifying property. The β-carotene has been better embedded by using CA-SC composite as surface stabilizer, and the droplets dispersed uniformly and with a droplet size of 222.65 nm, Emulsifying activity index (EAI) was 58.52 m 2 /g, emulsion stability index (ESI) was 42.22 min when the pH was 8.0. Thus, CA was better to be used to improve the emulsification stability of β-carotene by combining with SC as surface stabilizer.