Formation of Concentrated Particles Composed of Oppositely Charged Biopolymers for Food Applications – Impact of Processing Conditions

Publication date: Available online 21 October 2016 Source:Food Structure Author(s): Benjamin Zeeb, Catrin Stenger, Jörg Hinrichs, Jochen Weiss Associative complexation approaches are promising tools to generate mixed biopolymer particles with tailor-made physicochemical properties. However, association of oppositely charged biopolymers typically occurs under acidic conditions and low biopolymer concentrations. The present study aims to investigate intrinsic and extrinsic parameters to generate concentrated biopolymer dispersions which could be utilized as structuring agents in food matrices. We therefore utilized a multistep procedure. Firstly, solutions of whey protein isolate (WPI) and pectins with different degrees of esterification (DE) were mixed under neutral conditions at various ratios (WPI:Pectin 1:2, 1:1, 2:1, 5:1, 8:1). Secondly, the pH was adjusted to 3 to promote complex coacervation. Thirdly, complex dispersions were subsequently heat-treated to tailor their overall water content, whereas temperatures below (ϑ=50–55°C) and above (ϑ=90–95°C) the proteińs denaturation were applied. Phase separation behavior, microstructural, rheological and electrical properties of the complexes were investigated by surface charge, turbidity, particle size, rheometry and light microscopy measurements. Results revealed that complexes composed of WPI and pectin with a low DE formed rather small and dense particles, whereas large aggregates were observed when the pect...
Source: Food Structure - Category: Food Science Source Type: research