Influence of the type and concentration of hydrocolloids on Ostwald ripening of emulsions stabilized with small molecular and non-ionic surfactants.

The effects of hydrocolloid gum, gum arabic, carrageenan, and xanthan on the Ostwald ripening of emulsions fabricated using Brij or Tween surfactants were examined. Emulsions prepared using pure n-decane exhibited low stability to Ostwald ripening, and modifying the oil composition by mixing corn oil improved the stability to Ostwald ripening. When gums were added to emulsions prepared using pure n-decane, the stability to Ostwald ripening decreased further, except for xanthan in emulsions stabilized using Tween surfactant. This could be because gums may affect interactions between water molecules and the hydrophilic head of the surfactant, increasing the water solubility of n-decane. However, gum addition (or viscosity increment) increased the stability of emulsions prepared using the modified oil composition (90% n-decane and 10% corn oil). In conclusion, emulsions unstable to Ostwald ripening may be negatively affected by gum addition, whereas emulsions relatively stable to Ostwald ripening may be positively affected.

Fabrication of Whey Protein Isolate-Pectin Nanoparticles by Thermal Treatment: Effect of Dynamic High-Pressure Treatment.

This study investigated the impact of dynamic high-pressure (DHP) treatment on the ability of whey protein isolate (WPI) to form associative complexes with pectin and to form aggregate particles after their subsequent heat treatment. Light scattering showed that DHP treatments disrupted preexisting WPI aggregates and assembled pectin chains. Complexes formed from WPI/pectin mixtures at pH 4.5 were an order of magnitude smaller when formed after DHP treatment, regardless of the degree of esterification. WPI/pectin complexes formed after DHP treatment were more stable against subsequent pH neutralization than complexes formed without DHP treatment, and WPI/high-methoxyl pectin (HMP) complexes had greater stability than WPI/low-methoxyl pectin (LMP) complexes. WPI/pectin particles prepared by thermal treatment of complexes at pH 4.5 were also smaller when prepared after DHP treatment. WPI/HMP particles were stable to subsequent pH neutralization, while WPI/LMP particles became larger after neutralization.