mohammadi S, jafari S M, azari kia F, mirzaei H. Evaluation of rheological and structural characteristics of whey protein concentrate- gum tragacanth complex coacervation. FSCT 2019; 16 (87) :225-237
URL:
http://fsct.modares.ac.ir/article-7-23801-en.html
1- student
2- Professor
3- assistant professor
4- Associate professor , mirzaeihabib1@gmail.com
Abstract: (5452 Views)
Complex coacervation is generated through electrostatic interaction between oppositely charged biopolymers (proteins and polysaccharides). Complexation via electrostatic interactions can lead to formation of soluble or insoluble complexes. In the current research, the production and characteristics of the complexes formed from whey protein concentrate (WPC) and gum tragacanth (GT) were evaluated. In order to find the optimum pH for complexation, absorbance of protein-polysaccharide mixtures were measured at a wide range of pH (2–8), Furthermore, particle size, zeta potential, microstructure and rheological properties of the complexes were investigated. Based on the results, the best condition to form complex between WPC and GT was found to be at pH=4.5. With Increasing the amount of GT up to 0.75% w/w in a constant protein concentration (0.5% w/w), the lowest and highest particle size for WPC- GT complex was found at protein: polysaccharide ratio of 1: 1 (3018 nm) and 10:1 (4070 nm), respectively. Zeta potential changed from +3.11 mV (0% gum tragacanth) to -6.82 mV due to addition of GT (0.75% w/w). Microscopic images showed the presence of separate spherical particles, except at the concentration of 0.05% w/w. The appropriate rheological model to predict flow behavior of complexes was depended on protein-polysaccharide ratio and the dominate flow behavior index was found to be shear thinning. Increasing of TG concentration lead to lower flow behavior index as well as higher apparent viscosity, consistency coefficient and the yield stress
Article Type:
Original Research |
Subject:
food industry engineering Received: 2018/08/5 | Accepted: 2019/03/2 | Published: 2019/05/15