Konjac glucomannan octenyl succinate (KGOS) as an emulsifier for lipophilic bioactive nutrient encapsulation

Konjac glucomannan octenyl succinate (KGOS) has excellent emulsification properties and can potentially be used in the food industry as an emulsifier, stabilizer and microcapsule wall material. In the present study, the in vitro digestion properties and emulsification capability and stability of KGOS were studied to evaluate the transport and encapsulation characteristics of KGOS with insoluble bioactive nutrients.

Confocal scanning laser microscopy (CSLM) suggested that oil droplets could be encapsulated by KGOS into regular spheres. In vitro digestion properties showed that KGOS is effective for colon-targeted transport. β-Carotene was selected as a representative lipophilic bioactive compound to evaluate the emulsification characteristics of KGOS. The loading capacity of the 0.4 mg mL^-1 KGOS solution for β-carotene was 3.26%, and transmission electron microscopy suggested that the self-aggregate particles of KGOS/β-carotene (KGOSC) were more uniform than KGOS. With a composition of 0.03% β-carotene, 0.3% KGOS and 10% medium-chain triglycerides, the emulsification yield of the KGOSC nanoemulsion was more than 95%. After 30 days of storage, the particle size and polydispersity index of the KGOSC nanoemulsion were less than 5 nm and 0.5, respectively, and the sensitivity of KGOSC nanoemulsions to storage conditions decreased in the order temperature, oxygen and light.

The results of this study suggested that KGOS is a good potential emulsifier and stabilizer for lipophilic bioactive nutrient encapsulation. © 2018 Society of Chemical Industry.