Pickering emulsion gel stabilized by octenylsuccinate quinoa starch granule as lutein carrier: Role of the gel network.

Octenylsuccinate quinoa starch (OSQS) granule that stabilized Pickering emulsion gel with different gel networks by modulating the oil volume fraction (Φ) was developed as a carrier for lutein. Pickering emulsion gels stabilized by OSQS were achieved at Φ values ranging from 30% to 60%. Increasing Φ progressively increased the droplet size, storage modulus, and apparent viscosity, resulting in the formation of gel-like structure. Confocal laser scanning microscopy showed that OSQS formed a densely packed layer at the oil/water interface, the degree of aggregation between droplets increased, and the gel network enhanced through droplet flocculation with increasing Φ. After 31 days of storage, the retention index of lutein in the emulsion gel could reach 55.38%, and the corresponding half-life times increased from 12 to 41 days. This study will be useful for designing starch-based Pickering emulsion gel with tunable gel network and desirable characteristics as delivery carrier of sensitive bioactive compounds.