Encapsulation of Essential Oils in Zein Nanospherical Particles

Abstract

Three essential oils, oregano, red thyme, and cassia (100% pure oil), were encapsulated by phase separation into zein nanospheres. Topographical images indicated that the powders were made up of irregularly shaped particles ( approximately 50 mum) containing close-packed nanospheres. Approximately 31% of the oregano encapsulated particles had mean diameters greater than 100 nm compared to 19% for the zein alone particles. In vitro digestion of zein particles with pepsin at a concentration ratio of 10:1 was complete after 52 h in phosphate-citrate buffer, pH 3.5, at 37 degrees C by spectroscopic analysis. Nonenzymatic, aqueous in vitro release of essential oils from encapsulated zein particles was carried out in phosphate buffered saline at pH 7.4 and 37 degrees C. Release occurred at varying rates over 20 h probably from different locations within the closely packed nanospheres of different sizes. Gel electrophoresis SDS-PAGE of zein incubated with freeze-dried swine manure solids at 37 degrees C indicated that preformed microbial enzymes capable of digesting zein within minutes were present in the manure. Except for differences in size of nanospheres, no structural differences were resolved by several microscopic methods, suggesting that the oil and proteins phases were blended during phase separation.

Electrospun zein nanofibers incorporating cyclodextrins

“…Zein films and zein micro/nano particles can be used for encapsulation of essential oils, aromas and flavors, controlled release of active additives and as an active food packaging material, etc. (Alkan et al, 2011;Parris, Cooke, & Hicks, 2005;Patel, Heussen, Hazekamp, Drost, & Velikov, 2012;Sanchez-Garcia, Hilliou, & Lagaron, 2010;Shi, Kokini, & Huang, 2009;Zhong, Jin, Davidson, & Zivanovic, 2009). In the recent years, electrospinning of zein nanofibers have received much attention as well (Jiang, Reddy, & Yang, 2010;Jiang & Yang, 2011;Jiang, Zhao, & Zhu, 2007;Miyoshi, Toyohara, & Minematsu, 2005;Selling et al, 2007Torres-Giner, Gimenez, & Lagaron, 2008;).…”

Physicochemical Modification of Kafirin Microparticles and Their Ability To Bind Bone Morphogenetic Protein-2 (BMP-2), for Application as a Biomaterial

“…Kafirin microparticles have a rough surface and internal vacuoles resulting in a large surface area, whereas, zein microparticles are generally smooth and solid (6).…”

Encapsulation and Co-Precipitation Processes with Supercritical Fluids: Applications with Essential Oils

“…Other techniques such as annularjet or spinning-jet drying can be used to produce particles loaded with liquids such as essential oils. Table 3 shows some applications of these techniques for essential oil formulation [34][35][36][37][38][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75].…”

“…Finally, solidification of the coating is achieved by thermal, cross-linking or desolventization techniques. Another closely related technique is the organic phase separation, which can be considered as a reversed simple coacervation: a polymer phase separates and deposits on a core that is suspended in an organic solvent rather than in water Several essentials oils were encapsulated by coacervation employing gelatine [37,62], proteins [63] and other polymers [64]. …”