Effect Of Pterostilbene On Construction And Physicochemical Property Of W/O Nanoemulsion System

Pterostilbene is a small molecules with highly bioactivity,which can play a big role in the anti-oxidation,anti-inflammatory,antibacterial and anticancer.But due to its characteristics of instability,poor solubility in water,people often treat it as an embedding material loaded by nanoemulsion system,to increase the rate of dissolution and the purpose of improving bioavailability.However,the lipophilic small molecules also have certain hydrophilicity,which has a certain influence on the stability of the emulsion system and the oil-water interface.At present,there are few studies on this kind of small molecules.In this paper,the effect of Pterostilbene particles on the nanoemulsion system was firstly investigated by the measurement of the contact angle with oil and water.According to the property of Pterostilbene itself and inspection purpose,W/O type nanoemulsion system was selected to load Pterostilbene.To choose the best preparation conditions of nanoemulsion,several factors were selected,including the content of Pterostilbene,oil-water ratios,emulsifier content and pectin content,and a series of characterization parameters were tested,including particle size,Zeta potential,texture,rheological properties,and micromorphology.The best preparation conditions of the emulsion were selected to prepare Pterostilbene nanoemulsion and investigate the stability of the stable system.During the stability investigation of the emulsion system,the influence of different p H and salt solution concentration,as well as the change of physicochemical properties of the emulsion system under centrifugation,freeze-drying and repeated freeze-thawing were mainly studied.The experimental results are as follows:1.By measuring the contact angle of Pterostilbene,it was found that the contact angle of water was 58.932±1.005°,and the contact angle of oil was 12.483±0.033°,which indicated that Pterostilbene had strong lipophilicity and hydrophilicity to a certain extent.With this property,Pterostilbene can be used as surfactants to stabilize the oil-water interface.2.Camellia oil with the highest solubility was selected to prepare the Pterostilbene nanoemulsion,the best condition for preparing nanoemulsion are as follows: the oil phase was 60% compared with the water phase 40%,2%(w/v)Pterostilbene added,the emulsifying dose accounted for 10% of the oil phase,and the pectin adding amount was2%,the nanoemulsion system supported by these conditions was the most stable,and the emulsion type was confirmed to be W/O by the identification experiment.3.The surface tension of pterostilbene nanoemulsion was measured.The results of surface tension of blank group and Pterostilbene group were 45.1 m N/m and 42.4 m N/m.There were significant differences in the decrease of surface tension of emulsion after adding Pterostilbene.4.The Pterostilbene nanoemulsion system could maintain good stability at different p H values and promote the viscoelasticity of the oleogel system formed after lyophilization.The emulsion retention rate could be improved by the presence of Pterostilbene at low centrifugal speeds from 2000 to 8000 rpm.The stability of Pterostilbene nanoemulsion was better in low concentration salt solution.When the Na Cl concentration of emulsion increased beyond 0.1 M,the stability decreased slightly.However,after repeated freezing-thawing,Pterostilbene nanoemulsion appeared demulsification and stratification phenomenon,so it was speculated that pterostilbene could not stabilize the interface and caused the instability of the system.The specific reasons need to be further investigated.In this paper,by investigating the contact Angle of Pterostilbene granular material,it was determined that Pterostilbene had certain hydrophilicity and strong oleophilic property,and then prepared stable W/O nanoemulsion system to support Pterostilbene.Through the investigation of the physical and chemical properties of the system,it was speculated that PTE existed in the nanoemulsion system as small molecules at the oil-water interface,and supported the oil-water interface together with emulsifier,pectin and other substances.The presence of Pterostilbene improved the stability of the nanoemulsion,and showed certain resistance to the changes of the external environment.The results of this study will provide reference for the preparation of more stable nanoemulsion systems carrying small molecular active substances and further application.