Influence mechanism of chayote (Sechium edule) pectin on the stability of sodium caseinate emulsion

Chayote (Sechium edule), a vegetable with high economic value worldwide, is rich in pectin. At present, there are few reports on the application of chayote pectin (CP) in food emulsion. In this study, the effect of CP concentrations and system conditions (e.g, pH and NaCl concentrations) on the properties of sodium caseinate (CAS) emulsion were investigated, with apple pectin as the control. The addition of pectin increased the negative charge on the emulsion. For CAS-CP emulsion (mixing ratio was 2:1), the zeta-potential changed from positive (8.41 +/- 1.15 mV) to negative (-6.06 +/- 0.39 mV) at pH 4. In the neutral environment, when the CAS: CP mixing ratio was 2:1 and 1:1, the emulsion creaming indexes were (84.39 +/- 1.52) % and (66.04 +/- 1.53) %, respectively. In an acidic environment, due to the electrostatic repulsion, viscosity, and steric hindrance, the emulsion was stable when the mixing ratio of CAS: CP was 1:1. In addition, NaCl caused the phenomenon of creaming. The effects of apple pectin on the properties of CAS emulsion were similar to those of CP. Overall, this study can provide a novel idea for applying CP in emulsion.