Study On The Interactions Between The Characteristic Smoked Ingredients And Protein Of Smoked Sausage,and Its Taste Presentation Mechanism

In order to promote the application of liquid smoke in the production of smoked sausage and obtain better smoked flavor,reveal the relationship between the characteristic smoked ingredients and smoked sausage meat protein,explore the objective evaluation method of effect of smoked flavor on human taste and olfactory,this work conducts research on the processing of smoked sausage and human perception,mainly involving the following two modules:firstly,GC-MS,ET and E-nose was used to analyze the flavor components of the three liquid smoke,compare and determine the characteristic smoke components.Liquid smoke was used to different processing operations of smoked sausage,and SEM,LF-NMR and ET was used to detect its influence on smoked sausage's quality.Myofibrillar protein and sarcoplasmic were extracted from the four processing operations of pickled,vacuum rolled,chopped,poached.The total sulfhydryl content,surface hydrophobicity,and spectral information were used to analyze the changes in protein structure and the ability to adsorb characteristic smoked components in smoked sausage.Secondly,the composition,molecular structure and molecular descriptor information of the flavor components of the smoke liquid were collected.Homology modeling,molecular docking and molecular dynamics simulation were used to explore the interaction of 4-4-ethylguaiacol with human taste receptor TA2R1 and human olfactory receptor OR1G1.A QSAR model was established for multiple linear regression using the binding energy of flavor substances and human receptors as the dependent variable and flavor small molecule descriptors as the independent variable.The scientific experimental research in this work has four parts,and the main information is introduced as follows:1)Correlation between addition of liquid smoke and quality of smoked sausage.It was determined that the phenolic substance represented by 4-ethylguaiacol was the characteristic flavor substance of liquid smoke.E-nose's PA/2 and T70/2 sensors have strong response,reflecting the high content of organic compounds and aromatic compounds in the liquid smoke.ET analysis showed that the bitterness of the three smoked liquids was significantly higher than other tastes?P<0.05?.The smoked sausage with liquid smoke added in different processing operations was observed by SEM magnification of 10,000 times.It was found that the surface of the smoked sausage was smooth and the structure was dense in pickled.The smoked sausage relaxation time has three peaks in the range of 1?1000 ms and T22>T23>T21,which indicates that the hard-to-flow water content in sausage is the highest.Smoked sausage takes umami?coefficient 0.47?,saltness?coefficient 0.47?and richness?coefficient 0.42?as the first main component,with a contribution rate of 73.94%.2)Changes in protein structure and adsorption capacity of characteristic smoke components.The total sulfhydryl content and surface hydrophobicity of myofibrillar protein in different operations was higher than that of sarcoplasmic.Compared with raw meat,myofibrillar protein and sarcoplasmic protein decreased gradually?decrease rates were 31.43%and 61.87%,respectively?,and then increased rapidly?increased rates were 21.49%,64.03%?during the processing of smoked sausage.The surface hydrophobicity of vacuum rolled of the two proteins was the highest?P<0.05?,myofibrillar protein increased by 61%,and sarcoplasmic protein increased by 14.4%compared with raw meat.A slight red shift was occurred when the absorption peak of myofibrillar protein amide A band was 3444 cm^-1 in the vacuum rolled.The absorption peaks of amide B bands in the vacuum rolled and chopped operations were shifted to the left of 2925 cm^-1 and 2923 cm^-1 respectively compared with raw meat.The amide A bands of sarcoplasmic protein in vacuum rolled,chopped and poached were shifted from 3235 cm^-1 to 3440 cm^-1,3446 cm^-1 and 3433 cm^-1.The?max of myofibrillar protein in the vacuum rolled and chopped operations was red-shifted to 302 nm and 301nm.The free ratio of 4-ethylguaiacol in raw meat is 83.42%,and the vacuum tumbler is 69.79%,that was,30.21%of 4-ethylguaiacol is adsorbed by protein.3)Mechanism of human taste perception of smoked flavor.The structure-activity relationship model of flavor molecules in smoke liquid based on MLR and human taste receptor TA2R1 was established as R²=0.910,and the significant F change was 0.011.It was shown that there is a linear relationship between the binding energy of the molecular descriptors of smoked flavor components and human taste receptors,which can be reliably predicted by this model.The binding energy of 4-ethylguaiacol as a ligand to the human bitter taste receptor TA2R1 is-5.9 kcal/mol,and the hydrogen bond amino acid residue of TA2R1 and 4-ethylguaiacol was Arg55,which is hydrophobic Residues acting are:Leu48,Leu51,Ala96,Leu99,Gly100,Leu277.4)Structure-activity relationship analysis of human olfactory perception of smoked flavor.Human olfactory receptor OR1G1 obtained through homology modeling and used for molecular docking and dynamics research.The binding energy of 4-ethylguaiacol to the highest conformation of the human olfactory receptor OR1G1was-5.2 kcal/mol,the amino acid residues VAL108,MET109,GLU111,ALA112,THR202,GLY207,VAL248,SER249,PHE252 has a hydrophobic interaction with 4-ethylguaiacol.A structure-activity relationship model was established between the flavoring molecules of the liquid smoke and the human olfactory receptor OR1G1.The final R²=0.943 and the significant F change=0.015.This model predicted that the binding energy of flavoring components to the human olfactory receptor OR1G1 was reliable.