Calcium and chitosan-mediated clustering of whey protein particles for tuning their colloidal stability and flow behaviour. (October 2017)

• Record Type: Journal Article
• Authors: Vahedifar, Amir; Madadlou, Ashkan; Salami, Maryam
• Is Part Of: International dairy journal. Volume 73(2017)
• Page Start: 136
• Page End: 143
• Publication Date: 2017-10
• Subjects: Dairying -- Periodicals; Industrie laitière -- Périodiques; Electronic journals; 338.1762142
• DOI: 10.1016/j.idairyj.2017.06.003
• Languages: English
• ISSNs: 0958-6946

Abstract

Abstract: Whey protein microgel (WPM) particles were prepared by heating whey protein dispersions (40 mg mL −1 ) at pH 5.8 and 80 °C for 15 min. Supplementation with 5 mm CaCl2 at pH 6.0 increased the hydrodynamic diameter of WPMs, but did not influence the ζ-potential of the particles. The latter was attributed to clustering of WPMs by Ca 2+ bridges. Supplementing WPM suspension with chitosan (0.5 mg mL −1 ) at pH 5.0 caused formation of micron-sized clusters and a progressive increase in suspension viscosity over the subsequent 48 h. The latter was ascribed to development of a complexed lattice that inhibited sedimentation of WPMs. Immediately after chitosan supplementation, the WPM suspension changed from Newtonian to shear-thinning fluid. Fourier transform infra-red spectroscopy results suggested that microgelation proceeded by formation of inter-molecular β-sheets and loss of α-helix structure. It also indicated that chitosan may interact with WPMs at pH 6.0 through its acetyl groups.