Isolation And Identification Of Flavor Peptides From Yunnan Tartary Buckwheat And Its Condiment Base Preparation

Yunnan tartary buckwheat(Fagopyrum tataricum(L.)Gaertn.)is rich in protein and is a good resource for the development of taste peptide seasoning products.In this paper,tartary buckwheat protein was used as raw material,and the enzymatic hydrolysis process for the preparation of tartary buckwheat protein flavor peptide was optimized by response surface methodology.Ultrafiltration technology was used to fractionate,purify and enrich tartary buckwheat protein taste peptide,and an electronic tongue was used to evaluate it.Identification by screening the components with the best taste;using the screening components to carry out Maillard reaction to prepare and optimize tartary buckwheat flavor peptide seasoning base,and use headspace gas chromatography-mass spectrometry to analyze the flavor contribution in the process of Maillard reaction Compounds,the preparation process of Maillard reaction product microencapsulation was optimized by orthogonal experiment.The main research content and results of this paper are as follows:1.Taking the degree of hydrolysis as the evaluation index,the optimal process parameters of enzymatic hydrolysis of tartary buckwheat protein obtained by the response surface optimization method are: protease addition 7%,enzymolysis temperature 47 ℃,p H value 11.0,enzymolysis time 5 h,Three verification tests were carried out under this condition,and the degree of hydrolysis measured under this test condition was 26.57%.2.The taste peptides of tartary buckwheat protein were purified and enriched by ultrafiltration and ultrafiltration to obtain three components of <1 k Da,1～3 k Da,and3～5 k Da,which were screened by electronic tongue intelligent sensory technology <1k Da is the best taste component,the solution of this component is clear and transparent,and the taste profile analysis is significantly different from the other two components.The peptide sequence of this component was identified by LC-MS/MS,and 4 potential umami peptides were screened out from 93 identified peptides based on the amino acid sequence information.The sequence information is Gly-Arg-Ile-Gly-Glu-Thr-Leu(GRIGE-TL),Arg-Ala-Asp-Val-Phe-Asn-Pro-Arg-Ala-Gly(RADVFNPRAG),Leu-Arg-Gly-Asp-Asn-Asp-Gln-Arg-Gly-Phe(LRGDNDQR-GF),His-Ala-Asp-Val-Phe-Asn-Pro-Arg-Ala-Glu(HADVFNPRAG),the molecular weights are 745.42 Da,1102.58 Da,1177.57 Da,1083.53 Da,respectively,and the proportion of hydrophilic amino acids is 42.86%,40%,60%,40%,umami amino acids accounted for 57.14%,50%,50%,50%.3.Maillard reaction was carried out on the electronic tongue screening components(<1 k Da),and the influencing factors in the process of Maillard reaction were optimized by response surface optimization.Sensory evaluation and browning degree were used as evaluation indicators to obtain the best The Gamerard reaction process is as follows: the initial p H value is 8.0,the reaction temperature is 121°C,and the concentration of the reaction system is 15%.Under these conditions,the sensory score of the verification test results is 30.0,the sensory perception and solution browning degree are ideal,and the aroma is acceptable..The sweetness and umami taste were significantly improved before and after the Maillard reaction,and a large amount of umami amino acid aspartic acid was also detected in the solution after the reaction,and the total umami amino acids increased from 27.40 μg/m L to 501.33μg/m L m L,the total sweet amino acids increased from 8.23 to 153.00±16.37 μg/m L,and there was a significant difference(p<0.05).3 kinds of aldehyde compounds,4kinds of esters,8 kinds of hydrocarbons,2 kinds of phenols,5 kinds of alcohols and 2kinds of ketones were detected in the two components;,tangerine,and fat,these three types of substances all have lower odor thresholds(nonanal 0.001 mg/kg,nonanal0.0001 mg/kg),comparisons before and after the Maillard reaction process,enzymatic hydrolysis solution Maillard reaction The content of aldehydes in the liquid was significantly increased(p<0.05),and the Maillard reaction could effectively enhance the flavor;there were 4 esters that contributed to the flavor,among which dibutyl phthalate had a weak odor and low Odor threshold(0.0001 mg/kg),content decreased significantly after Maillard reaction(p<0.05),indicating that Maillard reaction has the effect of improving flavor.A total of 1003 differential metabolites were detected before and after the Maillard reaction of non-volatile substances by LC-MS/MS.Through classification analysis,it was found that oligopeptides,amino acids and amino acid derivatives mainly contributed to the reaction system.4.Using gum arabic and maltodextrin as wall materials,an orthogonal test was used to optimize the preparation process of Maillard reaction product microencapsulation,The results were that the inlet air temperature was 170°C,the feed flow rate was 300 m L/h,and the core-to-wall ratio was 1:2;the optimal combination was verified by verification tests,and the powder collection rate was42.69%..The external morphology of microcapsule particles was observed by scanning electron microscope.The surface appearance of the microcapsules was compact,spherical or irregular spherical,and the embedding effect of gum arabic and maltodextrin as wall materials was better.