Abstract
A new water-soluble anionic, low-molecular weight polysaccharide (gum) with surface, interfacial and emulsification properties was extracted from leaves of the legume Portulaca oleracea (termed by us POG). Vegetable oil-in-water emulsions with small droplets (2-5 μm), stable to flocculation and coalescence (for a few months) can be formed in the presence of 0.1-0.8 wt% POG. The gum adsorbs onto the oil-water interface. The nature of this adsorption was tested by evaluating the competitive adsorption of Tweens (ethoxylated sorbitan esters) and the POG in oil-in-water emulsions. It was demonstrated that Tweens form weak associates with the POG at the interface at certain emulsifier/gum binary mixtures, but any excess concentrations of the Tween will cause a gradual displacement of the gum from the interface. The POG and/or the gum-Tween associates (complex) have weak anchoring capabilities at the interface.
Original language | English |
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Pages (from-to) | 139-144 |
Number of pages | 6 |
Journal | Food Hydrocolloids |
Volume | 13 |
Issue number | 2 |
DOIs | |
State | Published - Mar 1999 |
Keywords
- Polysaccharide gum
- Portulaca oleracea
- Tween