Encapsulation of menhaden oil structured lipid oleogels in alginate microparticles

Abstract

Leaching of the internal phase during storage is a concern of microencapsulated products. This research proposes encapsulation of oleogels to reduce leaching and improve oxidative stability of the lipids. Oleogels were produced using a phytosterol blend of β-sitosterol/γ-oryzanol or a blend of sucrose stearate/ascorbyl palmitate (SSAP) as oleogelators, and menhaden oil or structured lipid (SL) prepared from menhaden oil and caprylic and/or stearic acid as the lipid phase. The SL were produced enzymatically using the biocatalyst Lipozyme® 435, a recombinant lipase from Candida antarctica. Menhaden oil, SL, or respective phytosterol or SSAP oleogels, were encapsulated in alginate microparticles using a double emulsion method. Encapsulation efficiency (EE), morphology, oxidative stability, percent leaching, and other physicochemical properties were determined. Encapsulation of phytosterol or SSAP oleogels increased the EE for all lipids, from 89.6 to 91.3% for microcapsules containing only the lipid phases and from 95.7 to 99.2% for microcapsules containing the oleogels. Encapsulation of oleogels significantly reduced leaching, from 16.3-18.5% to 3.3–11.9%. Microencapsulated products had higher Oil Stability Index values (19.75–29.18 h) than the non-microencapsulated lipids (4.37–17.55 h), when measured at 80 °C. These microcapsules may find use as stable nutraceuticals or in fortification of food products with stabilized omega-3 fatty acids.