Preparation And Digestion Of Lactoferrin-Cinnamic Acid Compound Seabuckthorn Seed Oil Gel

Developing food-grade delivery systems have become a hot spot of research to loaded hydrophobic bioactive molecules.Microgels assembled from natural polymers or micromolecule gelators^[1].Seabuckthorn seed oil is a functional oil rich in unsaturated fatty acids and hydrophobic nutraceuticals,which can provide essential fatty acids linolenic acid and linoleic acid for anti-inflammatory,liver protection,reducing the risk of chronic diseases^[2].However,lipid oxidation,poor light,heat stability,insoluble in water is the major concern of the food industry.Research has shown that food proteins can inhibit lipid oxidation and improve digestibility in food delivery systems.Cinnamic acid is a kind of micromolecule gelators.Lactoferrin,an emulsifying agent,used to create emulsions or microgels.In this study,lactoferrin and cinnamic acid was prepared oil-rich microgels.The stability and rheological characteristics of microgels was studied,and the digestion of seabuckthorn seed oil was investigated.The main results are as follows:?1?Microgels has been successfully constructed by lactoferrin,cinnamic acid and seabuckthorn seed oil.Organogels were prepared by dissolving cinnamic acid in seabuckthorn seed oil.Results showed that 4%?w/w?is the critical concentration to form organogels.Organogels stabilized with 6%?w/w?cinnamic acid.Near 100%oil trapped inside the organogels which stored at 4?overnight.On this basis,microgels prepared by lactoferrin and cinnamic acid.Microgels containing 20%lactoferrin,4%cinnamic acid and 65%seabuckthorn seed oil remain stable because of its small droplets.Microgels was highly unstable when stored at 85?elevated temperature or-18?cryogenic temperature,but stable when stored at 4?or 25?.Conversely,incorporation of the seabuckthorn seed oil loaded organogels into microgels greatly improved its stability.?2?The rheological properties of the microgels was characterized,which conclude mean square displacement curve,elasticity index,macroscopic viscosity index and solid-liquid-balance.The rheological results showed that microgels is a kind of non-newton fluid.Liquid behavior dominates organogels.The viscoelasticity of organogels with 4%or10%cinnamic acid much weaker than organogels with 6%or 8%,and its gel characteristics is weak.Organogels exhibited more obvious viscoelasticity which stored at4?.Compared with organogels,microgels has higher viscoelasticity.When the lactoferrin concentration was more than 20%,microgels exhibit solid-like behavior.The viscoelasticity of microgels is higher around 2%-8%cinnamic acid concentration or 65%loaded oil than other concentration.After stored at cryogenic temperature,microgels became viscous fluid,which indicates the breaking of existing network structure.It is proved that the 4?storing microgels has better viscoelasticity than the 25?storing microgels,and the same change occurred in the samples after 85?heating treatment.?3?The impact of lactoferrin or cinnamic addition on lipid digestion was determined by the fraction of free fatty acid?FFA?released from the samples.The results revealed that food delivery system increase the fraction of free fatty acids and decrease the initial rate of lipid digestion.In this section,a GIT model that simulated the mouth,stomach and small intestine stages of the human digestive tract was used to follow the potential gastrointestinal fate of the delivery systems.The initial system was mixed with simulated saliva fluid containing 3%mucin.The simulated gastric fluid containing 16 g/L pepsin.The simulated intestine fluid followed by 64 g/L of pancreatin and 10mM of bile salts.As the concentration of lactoferrin was increased from 5%to 25%,the FFA was gradually increased from 18.11%to 31.85%,but it is not significantly over concentration of 20%.The high fraction of lipid digestion in the microgels can be attributed to the large specific surface area of lipids exposed to the lipase.The addition of cinnamic acid to the microgels did not alter the FFA significantly but improve its deflocculated.The fact that there was an appreciable change in the initial rate of the fraction of FFA released from samples after cinnamic acid addition.These results indicate that cinnamic acid was an effective gelator for controlled-release microgels preparation.In conclusion,seabuckthorn seed oil loaded microgels could be successfully prepared by lactoferrin and cinnamic acid.Microgels is a solid behavior dominates system.For microgels,the fraction of FFA release can readily increase with the increasing lactoferrin concentration.The initial FFA release rate is appreciably slower with cinnamic acid addition,but decrease the fraction of FFA release not significantly.