Preparation And Properties Of Pickering Emulsion Loaded With Quinoa Saponins

In this study,Pickering emulsions with different saponin additions and different oil contents were prepared using buckwheat protein colloidal particles as emulsifiers.The properties of nine groups of emulsions were first characterized to investigate the effects of saponin addition and oil content on the emulsion properties.Three groups of emulsions with different saponin additions were selected to investigate the effects of temperature,salt concentration,p H and storage conditions on the stability of the emulsions using particle size,rheological properties,encapsulation rate,emulsion index and microstructure as indicators.The optimal slow release delivery emulsion system was screened by simulated in vitro digestion experiments.The antibacterial properties of Pickering emulsions loaded with quinoa saponin after digestion against Escherichia coli,Staphylococcus aureus and Salmonella enterica were investigated by in vitro antibacterial experiments.The results were as follows:1.Preparation and properties of Pickering emulsions loaded with quinoa saponins.Nine groups of Pickering emulsions with saponin addition of 1%,3%,5%(w/v)and oil content of 60%,70%,80%(v/v)were prepared using buckwheat protein colloidal particles as solid emulsifiers,and the emulsions were characterized for encapsulation rate,chromaticity,particle size,microstructure,rheological properties,zeta potential and bitter taste changes.The results showed that the three groups of emulsions with 80% oil content had higher encapsulation rate,better solid-like properties,gel structure and viscosity.The particle size of all nine groups of emulsions was small,with the smallest particle size(2.76 μm)for the emulsion with 1% saponin addition and 80% oil content(1-80%).The microstructure of the emulsions varied with oil content and saponin addition,with the 1-80% group having the most homogeneous and dense microstructure.The emulsions with less saponin addition and more oil content had higher zeta potential values.1-80% group emulsions were effective in masking bitterness and had no bitter aftertaste.Both the oil content and the amount of saponin added influenced the properties of the emulsions.The three groups of emulsions with 80% oil content had better properties,with the best emulsions in the 1-80% group.2.Stability studies of Pickering emulsions loaded with quinoa saponins.Three sets of emulsions with saponin addition of 1%,3% and 5%(w/v)and oil content of80%(v/v)were prepared and treated with different conditions.The stability of the three emulsions was investigated in terms of particle size,rheological properties,encapsulation rate,microstructure and emulsion index of the emulsions.The results showed that the emulsions with1% saponin addition were able to maintain a stable state under different conditions,with better thermal stability,centrifugal stability,salt concentration stability,p H stability and storage stability.3.In vitro digestion and antimicrobial properties of Pickering emulsions loaded with quinoa saponins.Nine groups of emulsions with saponin addition of 1%,3%,5%(w/v)and oil content of 60%,70%,80%(v/v)were prepared.The percentage of saponin release,free fatty acid release and bioavailability of saponin during digestion were determined by simulated in vitro digestion experiments.The results revealed that the 1-80% group of emulsions released saponins slowly,and the final percentage release of saponins,free fatty acid release and bioavailability were higher,which was the most suitable for slow release system.Combined with the emulsion stability results the 1-80% group emulsions were selected for antibacterial experiments.The antimicrobial effect of saponin-loaded emulsions on S.aureus,E.coli,and Salmonella enteritidis after digestion was verified by measuring the diameter of the inhibition circle,minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC),dynamic bactericidal curves,and release of cell contents,and the antimicrobial effect was long-lasting,with the best antimicrobial effect on S.aureus.1-80% group emulsions has high potential for application in slow release delivery and antibacterial.