Study On The Formation And Control Of The Hazards Associated With Maillard Reaction In Fermented Soy Sauce

In this study,the fermented soy sauce with large consumption is selected as the experimental object,and uses principal component analysis to test the correlation between the nutritional components of soy sauce in different fermentation stages and the hazards associated with Maillard reaction.Furthermore,the production of furan,CML and 5-HMF in the fermentation process was further studied through single reaction kinetics and Pearson correlation coefficient.At the same time,the inhibitory consequence of different exogenous additives on these three hazards was explored for subsequent precise control.Other hazardous Maillard reaction products in soy sauce provide theoretical support.The foremost results are as follows:(1)Principal component analysis(PCA)was used to investigate the relationship between the nutritional components(total reducing sugar,glucose,fructose,sucrose,free amino acids,total nitrogen,total acid,amino acid nitrogen and soluble salt free solids)and the associated harmful products(furan,CML and 5-HMF)of Maillard reaction.The results showed that the contents of glucose and fructose enlarged with the prolong of fermentation days.However,sucrose content showed the opposite trend.Similarly,in the fermentation process,the concentrations of amino acid nitrogen and total nitrogen increased rapidly at first and then decreased slowly.Soluble salt free solid level showed a fluctuating upward trend in the whole soy sauce fermentation process,and sterilized soy sauce concentration reached the highest.Glutamic acid and leucine were the most abundant free amino acids.Furan,CML and 5-HMF are potential hazards of Maillard reaction,and their contents increase with the extension of fermentation days.The maximum accumulation of furan,CML and 5-HMF in the samples reached the highest after sterilization.Principal component analysis further showed that the biggest variable that affects the level of furan,CML and 5-HMF were some free amino acids including histidine,isoleucine,arginine,threonine,phenylalanine,aspartic acid,valine,alanine,leucine and lysine,as well as glucose and fructose.That is,high concentrations of certain free amino acids,glucose and fructose will produce high levels of furan,CML and 5-HMF.(2)Using single reaction kinetics and Pearson correlation coefficient,the formation of furan,CML and 5-HMF in the fermentation process of soy sauce was preliminarily discussed.5-HMF can be formed in two ways: 3-DG dehydration and fructose dehydration.MGO and GO undergo various mechanisms including Schiff base formation,?-aminoketone condensation,and decarboxylation,resulting in the formation of furans in the presence of amino acids.CML can also be produced by reacting with lysine under aerobic conditions.Through the kinetic curve,the content of3-DG,MGO and GO in soy sauce increases with the increase of glucose and fructose content.Correspondingly,the content of 5-HMF,CML and furan also showed an increasing trend.Thus,the changes of 3-DG,MGO,GO,glucose and fructose and 5-HMF,CML and furan may have a certain correlation during the fermentation stage.Further testing with Pearson correlation(r)showed that there was a significant positive correlation between the levels of glucose,fructose,3-DG,MGO and GO and furan,CML and 5-HMF in soy sauce.This indicates that higher levels of glucose,fructose,3-DG,MGO and GO will lead to the production of high levels of furan,CML and 5-HMF.Therefore,furan,CML and 5-HMF formation can be effectively controlled by using raw materials with low sugar content or dicarbonyl capture agent.In addition,the fitting equation showed that the correction coefficients of determination of glucose,fructose,3-DG,furan,CML and 5-HMF were between 0.86 and 0.95,and the fitting degree was high.Therefore,nonlinear fitting method could be used to predict the production of glucose,fructose,3-DG,furan,CML and 5-HMF in soy sauce fermentation.(3)The effects of 4 different exogenous additives on furan,CML and 5-HMF in soy sauce were studied.Among them,the strongest inhibitory effect on furan is 50 ?M pcoumaric acid,followed by 50 ?M calcium chloride,10 ?M and 100 ?M EC,and 0.2%chitosan.As far as CML is concerned,calcium chloride and p-coumaric acid have a promoting effect at the addition amount of 10 ?M,while when the addition amount is50 ?M and 100 ?M,there is no significant difference from the control group.In addition,chitosan can reduce the production of 5-HMF in the soy sauce system,with an inhibition rate of up to 73%,which is the strongest inhibitor of the four exogenous additives.In addition,the effects of additives on the quality and properties of soy sauce were evaluated.The results showed that calcium chloride only reduced the level of total nitrogen in soy sauce at the dosage of 100 ?M.The concentration of amino acid nitrogen in the inhibitor group was similar to that in the control group,and was within the range of national standard.Moreover,the addition of coumaric acid and calcium chloride showed a significant inhibitory effect on the soluble salt-free solids in soy sauce.Among them,100 ?M had the highest inhibitory rate on coumaric acid,at 17%,followed by 100 ?M calcium chloride(13%)and 50 ?M calcium chloride(10%).Therefore,0.2% chitosan can be added to inhibit the formation of hazards associated with Maillard reaction in soy sauce.