Mangosteen Oil-In-Water Emulsions: Rheology, Creaming, and Microstructural Characteristics during Storage.

The rheological properties and physical stability
of mangosteen (Garcinia mangostana L.) extract in oil-inwater
(MIO/W) emulsions were investigated. Rheological
study on the emulsions exhibited Newtonian flow
behavior. The 20 wt.% emulsion showed higher apparent
viscosity than 10 wt.% MIO/W sample. The effects of
salt (NaCl) concentration (0, 50, 100, and 200 mM) and
heat treatment (70 °C) on the stability of the emulsions
were also examined. Heat (70 °C)- and NaCl (100 and
200 mM)-treated emulsions showed creaming and droplet
aggregation on storage for a period of 60 days. The
10 wt.% MIO/W emulsions stored at 4 °C showed a
homogeneous distribution of oil droplets with good
stability to creaming and viscosity independent of shear
stress (i.e., a Newtonian liquid).