Preparation And Stability Of Pickering Emulsion Of Macadamia Nut Isolate

Macadamia oil has widely used in industries,but the meals are wasted in many cases after extracting the oil,or are used as feed,and the high quality protein can not be used effectively.In this paper,the Australian nut protein emulsion was prepared and its stability was studied.The main results are as follows:The Australian nut protein isolate was prepared by Alkali extraction and acid precipitation method,Protein purity of 90.23%,then the Australian nut protein nanoparticles were prepared by pH-cycle method,and observed its microstructure.Macadamia separate protein nanoparticles can stabilize the emulsion,the shape of a more regular spherical,particle size between 100 to 180 nm,The particle size increases with increasing concentration,Zeta potential absolute value of more than30 mV,indicating that The prepared nanoparticles have good stability.The results show that the prepared nanoparticles have good thermal stability,and even if the particle size can be kept within 500 nm in the case of 100 ℃ water bath for 60 minutes,Protein nanoparticles were also tolerant to Na+ and K+ plasmas.Storage experiments showed that the prepared nanoparticles could be stable in the solution state at room temperature for a long time.The Australian nut protein isolate nanoparticles were prepared into a Pickering emulsion,The effects of different concentration,oil-water ratio,pH,ion,ion concentration and thermal sterilization on emulsion stability were studied systematically,and the storage stability experiment was carried out,then its rheological properties and microstructure were characterized.Studies have shown that the Australian nut protein isolate Pickering emulsion has been successfully prepared.Observations by CLSM（laser confocal microscopy）showed that the oil was encapsulated by the Australian nutrient protein nanoparticles.The rheological scanning indicates that the emulsion has shear thinning properties and weak gel properties.Australia nuts protein Pickering emulsion has a good storage stability,just prepared a day after the emulsion will produce stratification,then no longer change,a month after the oil did not produce the phenomenon.Increasing the concentration ofnanoparticles or the fat content can effectively reduce the analgesic effect of the macadamia nutrient protein in some extent.The emulsion can maintain good stability at pH 4,7,8.In the experiment of heat sterilization,it was found that the prepared emulsion had excellent stability in the environment of 70 ℃,100 ℃ heating can promote the emulsion gel,and can effectively reduce the emulsion index of the emulsion,indicating the pasteurization method and high temperature sterilization two kinds of thermal sterilization methods can be based on the production needs of the Australian nutrient protein Pickering emulsion separation.The Na+,K+ and Ca²⁺plasmas can promote the release of protein Pickering emulsion gel of Australia nuts,and even improve the stability of the emulsion.The Ca²⁺ effect is the most significant and can be effectively reduced Its emulsion index.