Complex coacervation between flaxseed protein isolate and flaxseed gum

- Kaushik, Pratibha, Dowling, Kim, Barrow, Colin, Adhikari, Benu

  • Authors: Kaushik, Pratibha , Dowling, Kim , Barrow, Colin , Adhikari, Benu
  • Date: 2015
  • Type: Text , Journal article
  • Relation: Food Research International Vol. 72, no. (2015), p. 91-97
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  • Description: Flaxseed protein isolate (FPI) and flaxseed gum (FG) were extracted, and the electrostatic complexation between these two biopolymers was studied as a function of pH and FPI-to-FG ratio using turbidimetric and electrophoretic mobility (zeta potential) tests. The zeta potential values of FPI, FG, and their mixtures at the FPI-to-FG ratios of 1:1, 3:1, 5:1, 10:1, 15:1 were measured over a pH range 8.0-1.5. The alteration of the secondary structure of FPI as a function of pH was studied using circular dichroism. The proportion of a-helical structure decreased, whereas both β-sheet structure and random coil structure increased with the lowering of pH from 8.0 to 3.0. The acidic pH affected the secondary structure of FPI and the unfolding of helix conformation facilitated the complexation of FPI with FG. The optimum FPI-to-FG ratio for complex coacervation was found to be 3:1. The critical pH values associated with the formation of soluble (pHc) and insoluble (pHΦ1) complexes at the optimum FPI-to-FG ratio were found to be 6.0 and 4.5, respectively. The optimum pH (pHopt) for the optimum complex coacervation was 3.1. The instability and dissolution of FPI-FG complex coacervates started (pHΦ2) at pH2.1. These findings contribute to the development of FPI-FG complex coacervates as delivery vehicles for unstable albeit valuable nutrients such as omega-3 fatty acids. © 2015.

Microencapsulation of omega-3 fatty acids : A review of microencapsulation and characterization methods

- Kaushik, Pratibha, Dowling, Kim, Barrow, Colin, Adhikari, Benu

  • Authors: Kaushik, Pratibha , Dowling, Kim , Barrow, Colin , Adhikari, Benu
  • Date: 2015
  • Type: Text , Journal article , Review
  • Relation: Journal of Functional Foods Vol. 19, no. Part B (2015), p. 868-881
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  • Description: To improve consumption of omega-3 fatty acids, foods can be enriched with omega-3 rich oils. Microencapsulation of omega-3 oils minimizes oxidative deterioration and allows their use in stable and easy-to-handle form. Microencapsulation of omega-3 fatty acids can be achieved by using a variety of methods, with the two most commonly used commercial processes being complex coacervation and spray dried emulsions. A variety of other methods are in development including spray chilling, extrusion coating and liposome entrapment. The key parameter in any of these processes is the selection of wall material. For spray dried emulsions and complex coacervates protein or polysaccharides are primarily used as shell material, although complex coacervation is currently commercially limited to gelatin. Here we review the need for microencapsulation of omega-3 oils, methods of microencapsulation and analysis, and the selection of shell material components. In particular, we discuss the method of complex coacervation, including its benefits and limitations. This review highlights the need for research on the fundamentals of interfacial and complexation behaviour of various proteins, gums and polyphenols to encapsulate and deliver omega-3 fatty acids, particularly with regard to broadening the range of shell materials that can be used in complex coacervation of omega-3 rich oils. © 2014 Published by Elsevier Ltd. All rights reserved.
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