Title page for ETD etd-11102009-155653


Type of Document Dissertation
Author Hannah, Sabrina
URN etd-11102009-155653
Title Microencapsulation of an omega-3 polyunsaturated fatty acid source with polysaccharides for food applications
Degree PhD
Department Food Science and Technology
Advisory Committee
Advisor Name Title
Duncan, Susan E. Committee Chair
Davis, Richey M. Committee Member
Marcy, Joseph E. Committee Member
O'Keefe, Sean F. Committee Member
Roman, Maren Committee Member
Keywords
  • pullulan
  • omega-3 fatty acid
  • fish oil
  • microencapsulation
  • spray drying
  • high-amylose starch
  • chitosan
Date of Defense 2009-10-27
Availability unrestricted
Abstract
Omega-3 polyunsaturated fatty acids (ω3 PUFAs) provide important health benefits, but

dietary consumption is low. Supplementing foods with ω3 PUFAs is of interest, but intervention

strategies are necessary to preserve the integrity of these unstable compounds.

Microencapsulation of ω3 PUFA sources is one means of improving their stability. In this work,

ω3 PUFA microcapsules were prepared by spray drying with chitosan and blends of chitosan,

high-amylose starch, and pullulan as wall materials. The primary objectives of this research

were (1) to evaluate the effect of chitosan type and oil:wall ratio on ω3 PUFA microcapsule

properties, (2) to evaluate the effect of blending chitosan with high-amylose starch and pullulan

on ω3 PUFA microcapsule properties, and (3) to evaluate the oxidative stability of ω3 PUFA

microcapsules by monitoring primary and secondary oxidation products during storage.

Microcapsule encapsulation efficiencies (EE) ranged from 63% to 79% with the highest EEs

observed for microcapsules prepared from chitosan with higher degree of deacetylation (DD) and

lower molecular weight (MW). Median microcapsule size ranged from 3μm to 11μm. Moisture

contents were all below 7% and water activities (aw) were below 0.27. Microcapsules prepared

from blends of chitosan with starch and/or pullulan had lower aw values than those prepared from

chitosan alone. Oxidative stability was evaluated by measuring oxidation induction time (OIT)

using pressure differential scanning calorimetry. OIT values ranged from 14 to 20 minutes.

Microcapsules prepared from chitosan with lower DD and higher MW had longer OITs than

those prepared from chitosan with higher DD and lower MW. Microcapsules prepared from

blends of chitosan, starch, and pullulan had longer OITs than those prepared from chitosan alone.

Oxidative stability of microcapsules during long term storage was evaluated on one microcapsule

formulation by monitoring peroxide value (PV) and secondary oxidation products by HS-SPMEGC/

MS. Volatiles including propanal, 1-penten-3-ol, pentanal, hexanal, and 2,4-heptadienal

were detected in the headspace of the microcapsules; however, PVs did not indicate substantial

oxidation of the ω3-PUFA source during 5 weeks of storage. Chitosan, high-amylose starch,

and pullulan are effective materials for microencapsulation of ω3 PUFA sources.

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