Complex coacervation with whey protein isolate and gum arabic for the microencapsulation of omega-3 rich tuna oil
- Authors: Eratte, Divya , Wang, Bo , Dowling, Kim , Barrow, Colin , Adhikari, Benu
- Date: 2014
- Type: Text , Journal article
- Relation: Food and Function Vol. 5, no. 11 (2014), p. 2743-2750
- Full Text: false
- Description: Tuna oil rich in omega-3 fatty acids was microencapsulated in whey protein isolate (WPI)–gum arabic (GA) complex coacervates, and subsequently dried using spray and freeze drying to produce solid microcapsules. The oxidative stability, oil microencapsulation efficiency, surface oil and morphology of these solid microcapsules were determined. The complex coacervation process between WPI and GA was optimised in terms of pH, and WPI-to-GA ratio, using zeta potential, turbidity, and morphology of the microcapsules. The optimum pH and WPI-to-GA ratio for complex coacervation was found to be 3.75 and 3 : 1, respectively. The spray dried solid microcapsules had better stability against oxidation, higher oil microencapsulation efficiency and lower surface oil content compared to the freeze dried microcapsules. The surface of the spray dried microcapsules did not show microscopic pores while the surface of the freeze dried microcapsules was more porous. This study suggests that solid microcapsules of omega-3 rich oils can be produced using WPI–GA complex coacervates followed by spray drying and these microcapsules can be quite stable against oxidation. These microcapsules can have many potential applications in the functional food and nutraceuticals industry.
Survival, oxidative stability, and surface characteristics of spray dried co-microcapsules containing omega-3 fatty acids and probiotic bacteria
- Authors: Eratte, Divya , Gengenbach, Thomas , Dowling, Kim , Barrow, Colin , Adhikari, Benu
- Date: 2016
- Type: Text , Journal article
- Relation: Drying Technology Vol. 34, no. 16 (2016), p. 1926-1935
- Full Text:
- Description: The objective of the study was to determine optimum inlet and outlet air temperatures of spray process for producing co-microcapsules containing omega-3 rich tuna oil and probiotic bacteria L. casei. These co-microcapsules were produced using whey protein isolate and gum Arabic complex coacervates as shell materials. Improved bacterial viability and oxidative stability of omega-3 oil were used as two main criteria of this study. Three sets of inlet (130 degrees C, 150 degrees C, and 170 degrees C) and outlet (55 degrees C, 65 degrees C, and 75 degrees C) air temperatures were used in nine combinations to produce powdered co-microcapsule. The viability of L. casei, oxidative stability of omega-3 oil, surface oil, oil microencapsulation efficiency, moisture content, surface elemental composition and morphology of the powdered samples were measured. There is no statistical difference in oxidative stability at two lower inlet air temperatures (130 degrees C and 150 degrees C). However, there was a significant decrease in oxidative stability when higher inlet temperature (170 degrees C) was used. The viability of L. casei decreased with the increase in the inlet and outlet air temperatures. There was no difference in the surface elemental compositions and surface morphology of powdered co-microcapsules produced under these nine inlet/outlet temperature combinations. Of the range of conditions tested the co-microcapsules produced at inlet-outlet temperature 130-65 degrees C showed the highest bacterial viability and oxidative stability of omega-3 and having the moisture content of 4.93 +/- 0.05% (w/w). This research shows that powdered co-microcapsules of probiotic bacteria and omega-3 fatty acids with high survival of the former and high stability against oxidation can be produced through spray drying.