Effect Of Ultra-high Pressure Treatment On The Functional Characteristics Of Millet Protein

[Purpose]In this experiment,millet was used as the raw material,the protein was extracted by alkaline extraction and acid precipitation method,and the extracted millet protein was subjected to ultra-high pressure treatment to explore the effect of ultra-high pressure treatment on the functional and digestive characteristics of millet protein.[Method](1)Taking the material-liquid ratio,temperature,extraction time and extraction p H as single factors,the millet protein extraction rate is an index.The millet protein extraction process is determined by single factor and orthogonal experiments.(2)Utilizing 100-500 MPa pressure and holding time for 10 min,the millet protein is subjected to ultra-high pressure treatment.Using untreated millet protein as a control group,the effects of ultrahigh pressure treatment on the solubility,foamability and foaming stability,emulsification and emulsification stability,water retention,oil retention,and secondary structure of millet protein were studied.(3)Through in vitro simulated digestion tests,analyze the changes in protein digestibility,hydrolysis degree,and peptide content of millet protein after ultrahigh pressure treatment,and explore the effects of different pressures on millet protein digestibility,hydrolysis degree,and peptide content.[Results](1)When the ratio of solid to liquid was 1:8,the time was 2h,the temperature was 30?,and the p H was 9.5,the extraction rate of millet protein was the highest,reaching 55.86%,and its purity was 81.6%.(2)After ultra-high pressure treatment,millet protein has some changes compared to before treatment.When the treatment pressure is200 MPa and 300 MPa,its solubility increases significantly(p<0.05).At 200 MPa,the solubility is the highest,20.98%.The solubility of millet protein decreases with increasing pressure.After 300-500 MPa treatment,the foamability of millet protein increased significantly(p<0.05),and reached the maximum at 500 MPa;while its foaming stability increased significantly(p<0.05)compared with the untreated,and was the highest at 100 MPa.After treatment,the emulsification of millet protein was significantly improved(p<0.05),reaching the maximum at 300 MPa,but there was no significant difference in emulsification between different treatment pressures.The emulsification stability of millet protein under200-500 MPa pressure was Compared with the control group,the increase was significant(p<0.05)and reached the maximum at 400 MPa.The water holding capacity of millet protein was significantly improved after treatment(p<0.01),and was the highest at 500 MPa.After100 MPa and 200 MPa ultra-high pressure treatment,the oil holding capacity of millet protein increased significantly(p<0.01),the maximum was at 200 MPa,and when the pressure was greater than 200 MPa,the oil holding capacity of millet protein decreased significantly(p<0.05).The secondary structure of millet protein undergoes ultra-high pressure treatment,and its stability also has a certain degree of influence.(3)After the ultra-high pressure treatment of100-500 MPa,the digestibility,hydrolysis degree,and peptide content of millet protein have been improved,indicating that the ultra-high pressure treatment has improved the digestibility characteristics of millet protein to a certain extent.[Conclusion]Ultrahigh pressure treatment had an effect on the functional and digestive properties of millet protein.