Construction Of Pickering And Traditional DHA Algal Oil Emulsion Systems And Its Product Development

DHA(docosahexaenoic acid)belongs to ?-3 unsaturated fatty acids(co-3 PUFAs),accounting for 10%-15%of cerebral cortical fatty acids,is an essential fatty acid for the human body.DHA participates in various physiological processes of the human body to maintain normal brain development and function.Algal oil is a high-quality DHA source.It is rich in DHA content(varies from 15%to 45%).However,algal oil is prone to oxidation and inconvenience in eating,which limits its application in the food field.Pickering emulsion is a novel emulsion system which is stabilized by colloidal particles rather than traditional small molecule emulsifiers or proteins,it has the advantages of strong milking stability,controllability and environmentally friendly,is a promising delivery system.This paper builds the Pickering and traditional algal oil emulsions to compare the physical and chemical stability,digestion characteristics of in vitro,and the potential of carrying DHA algal oil of different emulsions.Based on Pickering stabilization mechanism,DHA algal oil emulsion products with good taste and storage stability are developed to provide technical support for improving the absorption of algal oil DHA and expanding its application in the food field.The main findings are as follows:1.Using algal oil as the oil phase,prepared Pickering emulsion stabilized by gliadin nanoparticles(GL-EM)and sodium caseinate nanoparticles(NCP-EM)respectively.The environmental stability(thermal sterilization,freeze-thaw,pH,ionic and oxidation stability)of Pickering emulsions are compared with traditional emulsions(phospholipid emulsion,protein emulsion and small molecule surfactant emulsions).The results show that Pickering emulsions have good sterilization stability and freeze-thaw stability,and NCP-EM shows better pH stability and ionic stability,is more suitable for loading algal oil.2.The fatty acid composition of algal oil in this paper was determined.The main fatty acids of algal oil were linoleic acid and DHA(31.92%and 23.83%,respectively),while the EPA content(about 0.37%)was much lower than fish oil.The in vitro digestion characteristics of different algal oil emulsions were investigated by a simulated in vitro digestion model.The results show that the small molecule active agent emulsion has a higher release rate of fatty acid(FFA),and the release of FFA mainly depends on the droplet interface composition.Pickering emulsions have slower FFA release rate,and NCP-EM has better potential than GL-EM in algal oil carrying.3.Algal oil emulsion products were prepared based on NCP-EM Pickering emulsion.The effects of product formulations(emulsifier concentration,oil content,antioxidants,etc.)and process conditions(homogenization conditions,sterilization conditions)on the properties of algal oil emulsions(stability index,peroxide value,particle size,etc.)and quality of algae oil emulsion products(storage stability,taste and flavor)were investigated.The results show that the optimal preparation conditions of algal oil emulsion products are as follows:10%w/w of oil content,1%w/v of emulsifier concentration,and homogenized twice at 60 Mpa;the optimal antioxidant is EDTA plus TBHQ(Additional amounts are 0.01 and 0.015 g/kg emulsion,respectively);the optimal formula of algal oil emulsion product are as follows:10 g/L of sweet orange oil,80 g/L of sucrose,and adjust products' pH to 4.0,the product obtained has a good flavor.The optimal sterilization condition is 110?,15 min,the algal oil emulsion product obtained under the above conditions has good storage stability within 6 months.