Interfacial properties and antioxidant capacity of pickering emulsions stabilized by high methoxyl pectin-surfactant-pea protein isolate-curcumin complexes: Impact of different types of surfactants

Abstract

In the present study, high methoxyl pectin-surfactant-pea protein isolate-curcumin (HMP-surfactant-PPI-Cur) complexes were used as stabilizers for Pickering emulsions. The impact of different types of surfactants in the complexes, including rhamnolipid (Rha), tea saponin (TS) and ethyl lauroyl arginate hydrochloride (LAE), on the interfacial properties and antioxidant capacity of Pickering emulsions was investigated. The pH for the fabrication of complexes with desirable wettability of both aqueous and oil was determined by turbidimetric titration and contact angle measurement. The results showed that the pH of 3.2 was an optimal value to fabricate the complexes. Among these complexes, the HMP-Rha-PPI-Cur complex exhibited the optimal emulsifying property, since it exhibited a relatively low initial interfacial tension of 38.99 mN/m. Moreover, the result of the interfacial tension measurement indicated that the HMP-Rha-PPI-Cur complex could be rapidly adsorbed on droplets, and the adsorbed protein fraction was 99%. Furthermore, after 30 days of storage, the emulsion stabilized by the HMP-Rha-PPI-Cur complex exhibited the lowest serum index of 9.86% and peroxide value of 47.52 mmol/L. In summary, the interfacial properties, stability and antioxidant capacity of emulsions could be more effectively enhanced in the presence of Rha in the complex.