Fabrication And Properties Of Zein Based Propolis Delivery System By Anti-solvent Precipitation And PH Shifting

Propolis is a natural resinous mixture from many plant materials,buds,and exudates and is rich in polyphenols with several health beneficial properties.However,its application in food products and pharmaceuticals is hindered because of its low water solubility,undesirable sensorial characteristics and limited bio-accessibility.Although the fabrication of nanoparticles to delivery propolis has been researched for many years,many disadvantages still exist such as low encapsulation efficiency,low bio-accessibility and poor release profile of propolis in the gastrointestinal tract(GIT).Here,we originally report the design and synthesis of high encapsulation efficiency heat-denatured zein/CMCS nanoparticles as propolis carriers to enhance its oral bioavailability.The complex nanoparticles prepared under optimized conditions were spherical in shape with a Z-average diameter of?156 nm and zeta potential of?-30 mV.Encapsulation efficiency(EE)and loading content(LC)of propolis in heat-denatured zein/CMCS nanoparticles reached?83%and?13.83%,respectively.Fourier transform infrared(FTIR)indicated that hydrogen bonds,electrostatic and hydrophobic interactions were the major forces responsible for nanoparticle formation.The in vitro antioxidant activity of propolis encapsulated in nanoparticles was considerably stronger than that of propolis dispersed in water.This new approach of fabricating propolis-loaded heat-denatured zein/CMCS nanoparticle provides a promising strategy with high yield with improved water solubility,antioxidant activity and sustained release of propolis.Although heat-denatured Zein-CMCS nanoparticles are good propolis carriers,the anti-solvent precipitation process is tedious.There are two long-standing issues that are holding back the full exploitation of zein nanoparticles:(i)the use of ethanol and other organic solvents presents the flammability hazard in the industrial production and is also not preferred in health foods and(ii)unavailability of large-scale equipment to ensure efficient nondestructive zein colloidal particles.To overcome these,propolis loaded zein/caseinate/alginate nanoparticles were fabricated using a one-step procedure without using organic solvents and specialized equipment.The nanoparticles prepared under optimized method(method 3 sample)were spherical morphology with a well-defined diameter around 230 nm and a negative zeta potential around-30 mV.The encapsulation efficiency(EE)and loading capacity(LC)of propolis reached 87.5%and 60.2 ?g/mg by zein/NaCas/alginate nanoparticles,respectively.Formation of nanoparticles was involved with hydrogen bonds,hydrophobic and electrostatic interactions,which were confirmed by Fourier transform infrared spectroscopy(FTIR)analysis.These nanoparticles were shown to be stable towards aggregation over a wide range of pH values(2-8)and salt concentrations(0-300 mM NaCl).Compared to free propolis,the bioaccessibility of propolis encapsulated with nanoparticles was increased to 80%.Our results showed a promising clean and low-cost strategy to encapsulate hydrophobic nutraceuticals containing the hydroxyl group for applications in foods,supplements,and pharmaceuticals.