Study On Colloidal Micro Structures And Biological Activities Of Micro-/nano-Particles In Porcine Bone Soup

Bone soup is worldwide appreciated for its nourishing functions,besides the delicious taste.As a multi-phase dispersion,porcine bone soup contains massively the self-assembled colloidal micro/nano-particles(MNPs).The influences of colloidal microstructures on the characteristics and functions of bone soup are of common interests for better understanding food colloidal dispersions.Emulsification modulates the microstructure of colloids and subsequently the properties of these foods.The influences of emulsification on the stability,particle property and antioxidant activities of porcine bone soup are accessed here,by employing high speed shear homogenization with or without 8 kinds of emulsifiers at two concentrations(0.1 ‰ and 1‰,w/v).Meanwhile,MNPs and NPs were separated from porcine bone soup by ultrafiltration(UF)and size exclusion chromatography(SEC)respectively,and also be accessed the particle property and antioxidant activities.Moreover,UF-MNPs and SEC-NPs were labeled with Nile Red,and their uptake by rat's peritoneal macrophages and its consequent effects were investigated.The main results were shown as follow:(1)Emulsification modified the microstructure of porcine bone soup,e.g.elevating particle number,hydrodynamic diameter and net surface charge of MNPs,and subsequently increased emulsion stability of bone soup.Selected five typical emulsifiers,which were ?-cyclodextrin,Casesin,Lecithine,Gelatin,Tween80,from the eight in initial stage to promote the further test.(2)The morphology of UF-MNPs and SEC-NPs were showed as spherical particles with mean hydrodynamic diameter 248±10 nm and 170±1 nm,respectively.The temperature response of the UF-MNPs and SEC-NPs were better than bone soup and they are more stable at high pH value.Moreover,the components of amino acid and fatty acid were partly lost after the separation.(3)The addition of five emulsifiers generally increased the antioxidant capacities of emulsion,while the higher dose(1‰ w/v)further enhanced the peroxyl and DPPH radicals scavenging activities but weakened the ferric reducing power.But UF-MNPs and SEC-NPs were lower the antioxidant activitis of bone soup which caused by the different microstructure and the lost of antioxidant activity components.(4)UF-MNPs and SEC-NPs were found to be internalized by peritoneal macrophages up on co-incubation at particle/cell ratios of 14,000/1.In normal peritoneal macrophages,the particle uptake exerted influence neither on the cellular cytosolic membrane potential(Vmem)nor mitochondrial superoxide level,as were indicated with fluorescent dyes of DiBAC4(3)and MitoSOX Red,respectively.However,when peritoneal macrophages were challenged by peroxyl radical inducer AAPH,the engulfinent of UF-MNPs and SEC-NPs mitigated the peroxyl radical induced membrane hyperpolarization effect by up to 70%,and the suppression on the oxygen respiration in mitochondria by up to 100%.