Preparation Optimization Of Cyanidin-3-glucoside Multiple Emulsion And Study On In Vitro Simulation Digestion Characteristics

Anthocyanins are a large class of water-soluble plant pigments,possessing various physiological functions such as antioxidation,anticancer,liver function protection,anti-cardiovascular disease,anti-inflammation,and eye protection.However,it is reported the anthocyanin biological activity is very low.And at present,the detection method of anthocyanins is not perfect enough.How to improve the biological activity and detection method accuracy of anthocyanin to promote the widespread use of anthocyanins is the current research direction on anthocyanins.The W/O/W multiple emulsion has the advantages of sustained release,targeted release,increased stability,and improved bioavailability of internal aqueous phase materials.Embedding by W/O/W multiple emulsion is an important way to promote the bioavailability of hydrophilic substances.However,due to the thermodynamic instability of the multiple emulsion,the application in the food industry has been limited.At present,there are only a few reports on the anthocyanin multiple emulsion.However the low encapsulation efficiency,large particle size is still remains unsolved,and neither of them has created an acidic environment at pH=2,which all need further exploration.This study optimized the anthocyanin detect conditions firstly.Secondly preparation method and formul of W/O/W double emulsion was optimized,and then examined the ability of W/O/W double emulsion to embed Cyanidin-3-Glucoside multiple(C-3-G).Lastly,the characteristic of multiple emulsion on gastrointestinal digestive was detected.This study want to provide new ideas to improve he bioavailability of anthocyanins and develop anthocyanins new products.Specific conclusions are as follows:1.Optimization of pretreatment conditions for detection of anthocyanins.The citric acid,malic acid,tartaric acid,and HCl were used to examine the recovery rate of C-3-G under different pH conditions by HPLC,and then the stability of C-3-G at pH=2 under different acid were examined.The results showed that citric acid had the strongest ability to change anthocyanin to flavylium cation,followed by tartaric acid,malic acid and HCl.This ability may be related to the-COOgroups of citric acid and the structure of citric acid.Using HCl as a control,citric acid reduces the sensitivity of the anthocyanin to temperature and light,and promotes the stability of anthocyanins.Tartaric acid increases the sensitivity of anthocyanins to temperature and light,which is not conducive to the stability of anthocyanins.Malic acid has no significant effect on the stability of anthocyanins.In summary,it is recommended to use citric acid to create an acidic environment atpH=2 which increase anthocyanin detection accuracy.2.The establishment and optimization of the preparation method of W/O/W multiple emulsion.Using centrifuge retention,rheology,and microstructure as indicators,single-factor experiments and uniform design experiments were conducted to optimize the preparation process and formula of the multiple emulsion.The optimized conditions were obtained: the primary emulsion stirring rate was15,500 rpm,the multiple emulsion stirring rate was 7,000 rpm,the mass ratio of primary emulsion water to oil is 3:7,the content of NaCl in internal water phase is 0.1 %(w/w),the content of xanthan gumin internal water phase is 0.2 %(w/w),the content of oil phase emulsifier PGPR is 16 %(w/w),and the HLB of external water phase emulsifier is 10,the external aqueous phase emulsifier content is 10%,the content of xanthan gum in external aqueous phase is 0.2 %(w/w),and the mass ratio of primary emulsion to external aqueous phase is 5:5.3.Preparation and Characteristics of Cyanidin-3-Glucoside multiple emulsion.The C-3-G was embedded in the optimized multiple emulsion.The effects of embedding C-3-G on the centrifuge retention,rheology,potential,particle size,and microstructure of the multiple emulsion were examined.The drug loading and entrapment efficiency of C-3-G multiple emulsions were also determined.The results showed that the drug loading of C-3-G multiple emulsions was 1500 ppm,the encapsulation efficiency was 98.08±1.56 %,the particle size was 688.99±30.91 nm,and the potential was-27.61 ±0.78 mV.Under the condition of at 4 ° C without light,C-3-G multiple emulsion can be stored for two weeks.4.In vitro simulated digestion characteristics of cyanidin-3-glucoside multiple emulsions.C-3-G multiple emulsions digestion was performed using a lipid digestion model.With the C-3-G solution as a control,the C-3-G release rate,the concentration of C-3-G in the Simulated digestive fluid,the C-3-G residual rate,and the microstructural changes of multiple emulsion were observed during the digestion.The results showed that the C-3-G multiple emulsions structure remained intact in the gastric simulated system,but was destroyed in the small intestine,and only 10 % C-3-G was released in the gastric while more than 53% of the C-3-G was released in the small intestine.The system can significantly improve the stability of C-3-G in the gastrointestinal tract,and promote the release of C-3-G in the intestine.