Influence of polysaccharides on the rate of coalescence in oil-in-water emulsions formed with highly hydrolyzed whey proteins.
The objective of this study was to examine the effects of added xanthan gum, guar gum, or kappa-carrageenan on the formation and properties of emulsions (4 wt % corn oil) formed with an extensively hydrolyzed commercial whey protein (WPH) product under a range of conditions. The rate of coalescence was calculated on the basis of the changes in the droplet size of emulsions during storage of the emulsions at 20 degrees C. Compared with the emulsion made without the addition of polysaccharides, the rate of creaming and coalescence in emulsions containing xanthan gum, guar gum, or kappa-carrageenan was markedly enhanced with increasing concentration of polysaccharides during storage for up to 7 days. At a given concentration, the rate of coalescence was highest in the emulsions containing guar gum, whereas it was lowest in the emulsions containing kappa-carrageenan. All emulsions containing xanthan gum, guar gum, or kappa-carrageenan showed flocculation of oil droplets by a depletion mechanism. This flocculation was considered to enhance the coalescence of oil droplets. The different rates of coalescence could be explained on the basis of the strength of the depletion potential, which was dependent on the molecular weight and the radius of gyration of the polysaccharides.
Riddet Centre and Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
Aiqian
A
Ye
Yacine
Y
Hemar
Harjinder
H
Singh
D002351:Carrageenan / Q000494:pharmacology; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003314:Corn Oil / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry*; D005685:Galactans / Q000494:pharmacology; D006868:Hydrolysis; D008351:Mannans / Q000494:pharmacology; D018613:Microscopy, Confocal; D008894:Milk Proteins / Q000737:chemistry*; D053149:Plant Gums; D011134:Polysaccharides / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D014867:Water / Q000737:chemistry; D000067816:Whey Proteins
D004655:Emulsions; D005685:Galactans; D008351:Mannans; D008894:Milk Proteins; D053149:Plant Gums; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D000067816:Whey Proteins; D014867:Water; D003314:Corn Oil; D002351:Carrageenan; C007894:guar gum; C002563:xanthan gum