Concentrated whey as protein source for thermally stabilized whey protein-pectin complexes

摘要

The suitability of ultrafiltered skim milk microfiltration permeate, concentrated 'ideal whey', (W-con) as protein source in comparison to whey protein isolate (WPI) for thermomechanical whey protein-pectin complex (WPPC) formation with a scraped-surface heat exchanger on laboratory scale was investigated. Protein concentrations were between c(low) = 0.7% and c(high) = 5.20% (protein:pectin = 5:1) and representative shear rates (gamma)over dot(rep) ranged from 150 to 675 s(-1). WPPCs were analyzed by intrinsic fluorescence spectroscopy, static light scattering, light microscopy, and apparent particle binding energies sigma* were calculated.With increasing (gamma)over dot(rep) WPPC size decreased. An influence of protein source on complex assembly was found as sigma* was about four times higher whilst using instead of WPI (at equal c). Finally, W-con (at (gamma)over dot(rep) > 500 s(-1)) is suitable to obtain WPPCs with desired properties (primary complexes with d(90,3) < 10 mu m) for applications as fatreplacers in dairy matrices.