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	spray drying microencapsulation fish oil omega-3 fatty acid pullulan high-amylose starch chitosan
Date of Defense	2009-10-27
Availability	restricted
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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