Structure Identification And Preparation Of Umami Peptide From Sunflower Protein

Defatted sunflower meal is the main byproduct during sunflower oil production,which is rich in proteins,especially glutamic and aspartic(umami amino acids)content of up to 30%.It can be utilized as tasty substance.In this paper,sunflower protein isolate was processed which using sunflower meal as raw material.Protein hydrolysate of sunflower was prepared by enzymatic hydrolysis and discusses the properties of umami hydrolysate Furthermore,the structures which belongs to separation and purification of protein hydrolysate of sunflower was identified.The results of the research as follows.First of all,the sunflower protein enzymatic hydrolysate with umami intensity were prepare sunflower protein.The results shows that the preparation of sunflower protein enzymatic hydrolysate,the hydrolysate had the highest value of umami intensity(11.54)by Flavorzyme under the condition of p H7.0,substrate concentration 2.5%,temperature 55?,amount of enzyme 4%.Secondly,effect of umami hydrolysate of sunflower protein on the freshness of IMP.The results shows that sunflower protein hydrolysate with a molecular weight of 3~5k Da has the best effect on IMP and umami intensity with increasing concentrations gradually increased,but sunflower hydrolysates concentration 4mg/ml,the effect of umami-enhancing is no longer significant.Three umami peptides were isolated and purified by ultrafiltration,gel filtration chromatography and reverse high-performance liquid chromatography(RP-HPLC).The active peptides were identified to be DVNNPANQLD? NNENQLDEYQR and EFEGGSIEH by MS,respectively.These umami peptides with the characteristics: the highest percentage of umami amino acid at leas 60% and hydrophobic amino acids account for less than 40%.