Microencapsulation of omega-3 fatty acids from flaxseed oil in flaxseed protein and flaxseed gum based matrix
- Authors: Kaushik, Pratibha
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The overarching goal of this research was to develop microencapsulated flaxseed oil as a plant based source of omega-3 fatty acids. To accomplish this, flaxseed oil was microencapsulated in a novel matrix composed of flaxseed protein isolate (FPI) and flaxseed gum (FG) and converted into a powder by freeze drying and spray drying. The primary objectives were: a) To evaluate the physicochemical and functional properties of FPI and FG; b) to optimise the process of complex coacervation between FPI and FG to maximise the yield of complex coacervates; c) to characterise the flaxseed oil microcapsules obtained through complex coacervation followed by freeze drying or spray drying. FPI and FG were extracted from whole flaxseeds at optimised temperatures to obtain 90% purity. The physicochemical and functional properties of FPI were found superior to most of the commonly used proteins. Lower extraction temperatures (30, 50 °C) of FG yielded higher levels of neutral monosaccharides and lower levels of acidic monosaccharides. The functional properties of FG, such as EAI and WAC, were negatively affected by the rise in extraction temperature. Electrostatic complexation studies between these two biopolymers showed that the optimum FPI-to-FG ratio is 3:1 and the optimum pH is 3.1. The complex coacervates of FPI-FG were used to microencapsulate flaxseed oil at different core to wall ratios (1:2, 1:3 and 1:4), and converted to powder through spray drying and freeze drying. The spray dried solid microcapsules had higher oil microencapsulation efficiency, lower surface oil content and higher oxidation stability compared to the freeze dried microcapsules. The oxidation stability obtained from spray dried microcapsules at core-to-wall ratio of 1:4 was nearly double to that of the unencapsulated flaxseed oil. This study affirms the potential of a solely plant based encapsulating matrix that returns superior nutritional outcomes to other commonly used wall materials.
- Description: Doctor of Philosophy
Survival and fermentation activity of probiotic bacteria and oxidative stability of omega-3 oil in co-microcapsules during storage
- Authors: Eratte, Divya , Wang, Bo , Dowling, Kim , Barrow, Colin , Adhikari, Benu
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of Functional Foods Vol. 23, no. (2016), p. 485-496
- Full Text: false
- Reviewed:
- Description: Tuna oil (O) and probiotic bacteria Lactobacillus casei (P) were co-microencapsulated in whey protein isolate (WPI)-gum Arabic (GA) complex coacervate. The co-microcapsules (WPI-P-O-GA), L. casei microcapsules (WPI-P-GA) and tuna oil microcapsules (WPI-O-GA) were converted into powder using spray and freeze drying. The interaction between probiotic bacteria and omega-3 oil in co-microcapsules, particularly in terms of oxidative stability of omega-3 oil and vitality/viability of probiotic bacteria and any synergistic outcome, was studied. The effect of storage temperature (5 and 25 °C) and time (90 days) on the survival and fermentation activity of L. casei and oxidative stability of tuna oil in the microcapsules/co-microcapsules was determined. A synergism between oxidative stability of omega-3 oil and vitality of probiotic bacteria was observed, when they were co-microencapsulated and spray dried. These co-microcapsules will likely have utility in functional food formulations due to simple and cost effective stabilisation and delivery of two important functional ingredients. © 2016 Elsevier Ltd.
Co-encapsulation of Omega-3 fatty acids and probiotic bacteria through complex coacervation
- Authors: Eratte, Divya
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The research described in this thesis investigated the microencapsulation of omega-3 oil and probiotic bacteria together in a protein-polysaccharide complex coacervate matrix. The synergistic or competitive interactions between the probiotic bacteria and omega-3 fatty acids when packaged in a single microcapsule was determined including how best to utilise such interaction to achieve improved oxidative stability of omega-3 fatty acid and better survival of the probiotic bacteria. Encapsulation and co-encapsulation of tuna oil (O) and Lactobacillus casei 431 (P) as models of omega-3 and probiotic bacteria, respectively, were carried out and the works is described in this thesis in five distinct sections. (1) The optimisation of the complex coacervation process between whey protein isolate (WPI) and gum Arabic (GA). (2) Microencapsulation of tuna oil (O) in WPI-GA complex coacervates followed by spray and freeze drying to produce microcapsules (WPI-O-GA). (3) Microencapsulation of probiotic bacteria L. casei 431 (P) in WPI-GA complex coacervates followed by spray and freeze drying to produce microcapsules (WPI-P-GA). (4) Co-encapsulation of omega-3 oil and L. casei 431 together in WPI-GA coacervate matrix followed by spray and freeze drying to produce co-microcapsules (WPI-P-O-GA). (5) In-vitro digestion evaluation of co-microcapsules and microcapsules to indicate bioavailability. The viability of L. casei was significantly higher in WPI-P-O-GA co-microcapsules than in WPI-P-GA microcapsules in both spray and freeze dried microcapsules. The oxidative stability of tuna oil was significantly higher in spray dried co-capsules. Also, co-microencapsulation increased the survivability of L. casei during simulated digestion. There was no significant influence observed on the release properties of omega-3 oil due to co-microencapsulation. However, the total omega-3 fatty acids in the released oil during in-vitro digestion were found to be higher, when co-microencapsulated. Hence, co-microencapsulation was shown to protect the L. casei and deliver both viable cells and omega-3 oil to human intestine without any significant adverse effect on their functionality and properties.
- Description: Doctor of Philosophy
Co-encapsulation and characterisation of omega-3 fatty acids and probiotic bacteria in whey protein isolate-gum Arabic complex coacervates
- Authors: Eratte, Divya , McKnight, Stafford , Gengenbach, Thomas , Dowling, Kim , Barrow, Colin , Adhikari, Benu
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Functional Foods Vol. 19, no. (2015), p. 882-892
- Full Text: false
- Reviewed:
- Description: Omega-3 fatty acids and probiotic bacteria were co-encapsulated in a single whey protein isolate (WPI)-gum Arabic (GA) complex coacervate microcapsule. Tuna oil (0) and Lactobacillus casei 431 (P) were used as models of omega-3 and probiotic bacteria, respectively. The co-microcapsules (WPI-P-O-GA) and L. casei containing microcapsules (WPI-P-GA) were converted into powder by using spray and freeze drying. The viability of L. casei was significantly higher in WPI-P-O-GA co-microcapsules than in WPI-P-GA. The oxidative stability of tuna oil was significantly higher in spray dried co-capsules than in freeze dried ones. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.
Microencapsulation of flaxseed oil in flaxseed protein and flaxseed gum complex coacervates
- Authors: Kaushik, Pratibha , Dowling, Kim , McKnight, Stafford , Barrow, Colin , Adhikari, Benu
- Date: 2016
- Type: Text , Journal article
- Relation: Food Research International Vol. 86, no. (2016), p. 1-8
- Full Text: false
- Reviewed:
- Description: Flaxseed oil, a rich source of omega-3 fatty acids, was microencapsulated in a novel matrix formed by complex coacervation between flaxseed protein isolate (FPI) and flaxseed gum (FG). This matrix was crosslinking with glutaraldehyde. Liquid microcapsules with three core (oil)-to-wall ratios (1:2, 1:3 and 1:4) were prepared and spray-dried or freeze-dried to produce powders. The microencapsulation efficiency, surface oil, morphology and oxidative stability of these microcapsules were determined. The spray-dried solid microcapsules had higher oil microencapsulation efficiency, lower surface oil content, smoother surface morphology and higher oxidation stability than the freeze-dried microcapsules. The highest microencapsulation efficiency obtained in spray-dried microcapsules was 87% with a surface oil of 2.78% at core-to-wall ratio 1:4 and oil load 20%. The oxidation stability obtained from spray-dried microcapsules at core-to-wall ratio of 1:4 was nearly double that of the unencapsulated flaxseed oil. © 2016 Elsevier Ltd.