Preparation and characterization of water/oil/water emulsions stabilized by polyglycerol polyricinoleate and whey protein isolate

J Food Sci. 2010 Mar;75(2):E116-25. doi: 10.1111/j.1750-3841.2009.01487.x.

Abstract

In this study we tried to prepare stable water-in-oil-in-water (W/O/W) emulsions using polyglycerol polyricinoleate (PGPR) as a hydrophobic emulsifier and whey protein isolate (WPI) as a hydrophilic emulsifier. At first, water-in-oil (W/O) emulsions was prepared, and then 40 wt% of this W/O emulsion was homogenized with 60 wt% aqueous solution of different WPI contents (2, 4, and 6 wt% WPI) using a high-pressure homogenizer (14 and 22 MPa) to produce W/O/W emulsions. The mean size of final W/O/W droplets ranged from 3.3 to 9.9 microm in diameter depending on the concentrations of PGPR and WPI. It was shown that most of the W/O/W droplets were small (<5 microm) in size but a small population of large oil droplets (d > 20 microm) was also occasionally observed. W/O/W emulsions prepared at the homogenization pressure of 22 MPa had a larger mean droplet size than that prepared at 14 MPa, and showed a microstructure consisting of mainly approximately 6 to 7-microm droplets. When a water-soluble dye PTSA as a model ingredient was loaded in the inner water phase, all W/O/W emulsions showed a high encapsulation efficiency of the dye (>90%) in the inner water phase. Even after 2 wk of storage, >90% of the encapsulated dye still remained in the inner water phase; however, severe droplet aggregation was observed at relatively high PGPR and WPI concentrations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Castor Oil / chemistry*
  • Chemical Phenomena
  • Chemistry, Physical
  • Emulsions / chemistry*
  • Glycerol / analogs & derivatives*
  • Glycerol / chemistry
  • Milk Proteins / chemistry*
  • Ricinoleic Acids / chemistry*
  • Water / chemistry*
  • Whey Proteins

Substances

  • Emulsions
  • Milk Proteins
  • Ricinoleic Acids
  • Whey Proteins
  • glyceran polyricinoleic acid ester
  • Water
  • Castor Oil
  • Glycerol