Stability of whey protein concentrate/sunflower oil emulsions as affected by sucrose and xanthan gum

CRISTIÁN HUCK IRIART; JAIME A RINCON CARDONA; MARIA LIDIA HERRERA

FOOD AND BIOPROCESS TECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2014 p. 1 - 11

1935-5130

The effect of addition of sucrose and xanthan gum on stability of emulsions formulated with two commercial whey protein concentrate powders was studied following systems changes with a Turbiscan TMA 2000, a light scattering equipment and a confocal laser scanning microscope. Two different processing methods were compared: homogenization by Ultraturrax (UT) and by Ultrasound (US). Addition of sucrose to the aqueous phase of emulsions significantly diminished volume weighted mean diameter (D43) and improved stability. When the aqueous phase contained xanthan gum, the main destabilization mechanism for UT emulsions changed from creaming to flocculation. For US emulsions, although some aggregation was detected by confocal laser scanning microscopy, it was not great enough to modify the BSav in the middle zone of the tube (20-50 mm). At low protein concentrations, the profiles corresponded to destabilization of small aggregates. In those conditions, creaming was markedly enhanced as evident from creaming rate values. Independently of aqueous phase composition, US emulsions stabilized by protein concentrations higher than 5 wt.% were stable indicating that whey proteins were good emulsions stabilizers at pH close to 7. This study shows the relevance of protein type on stability and describes for the first time a different behavior for whey proteins than the one reported for caseins in literature.