Study On Formation Mechnism And Control Of Biogenic Mines During The Process Of High-salt Diluted Soy Sauce

Soy sauce is the traditional condiment in China and Asian countries, so the safety isclosely related to the health of people. Biogenic amines are detected mainly in fermented food,mainly formed by the decarboxylation of amino acids by microbial and high amounts of themmay cause food borne intoxication. There is little knowledge in literature about the dynamicchange of biogenic amines in the fermentation process of soy sauce. So the objective of thisstudy is to investigate the formation and control of biogenic amines in the process of high saltdiluted state soy sauce.This information will be useful to enhance the quality of soy sauce andimprove the technology of fermentation metabolism control.An analytical method for simultaneous determination of trypatamine, phenylethylamine,putrescine, cadaverine, histamine, tyramine, spermidine and spermine in soy sauce by HPLCwas developed.Under the optimal conditions, linear range was1.0-50mg/L for biogenicamines and the correlation coefficient(R2) was greater than0.99. The limits of detection werein the range of0.075-0.3mg/L. At the spiked levels of1.00and5.00mg/L, the averagerecoveries were83%-111%with the relative standard deviations of0.43%-19%. The resultsshowed that the proposed method has a good linearity and sensitivity which is suitable todetect biogenic amines in soy sauce.The established method has been successfully applied to determine biogenic amines in36commercial soy sauce samples.The results showed that concentration of biogenic amineswere mainly in the range of41.18-1898.17mg/L, and tyramine, putrescin andphenylethylamine were found to be predominant amines in soy sauce samples.Overall, thehigher the level of Chinese soy sauce, the higher the concentration of biogenic amines is.The concentration of biogenic amines is higher in high-salt diluted soy sauce than in low-saltsoy sauce, and the concentration of biogenic amines in Chinese soy sauce is higher than inJapanese soy sauce.Biogeic amines, microbiological changes and physicochemical properties during thefermentation process of soy sauce in different seasons were analyzed. The results showedthat the biogeic amines increased with the fermentation time in both laboratory andindustrial scale, and increased fastest in the early stage of fermentation.The rate of biogenic amines formation is different between laboratory and industrial level.The content and compositon of biogenic amines was quite different between laboratoryand industrial scale, and the content of biogenic amines in industrial scale was ten timeshigher than in laboratory scale. In laboratory scale the main biogenic amines were putrescine,phenylethylamine and spermidine, and in laboratory scale putrescine,histamine andtyramine were the predominant biogenic aimes. Seasons had big effect on the content of totalbiogenic amines and the single amine, but a small effect on the composition of biogenicamines, and the content of biogenic amines in winter was lowest in both two scales.Temperature had big effect on the formation rate of biogenic amines, the formation rate ofbiogenic amines at summer was higher than the other three seasons in both laboratory andindustrial scale.The relation between biogenic amines and environment conditons, microbiology,microenvironment of microorganism had been analyzed. The result showed that, there was agood correlation between them. Total amine content of the four seasons of laboratory andindustrialized scale high salt diluted state fermented soy sauce had a significant correlationwith amino acid, total nitrogen and total free amino acids（p<0.05）, and had a significantnegative correlation with pH value, total number of colonies and lactic acid bacteria（p<0.05）.Researches on using different starch material and adding citric acid and acetic acidbefore koji-making to control the biogenic amines during the fermentation process of highsalt diluted state soy sauce were studied.The results showed that koji of the bran and ricebran and adding acetic acid can effectively reduce the total biogenic amines in soy sauce,and reduce the accumulation of histamine, spermidine and spermine, but adding citric acidhad no apparent inhibition of biogenic amines in soy sauce.