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Identification of Biogenic Amines Produced by Lactic Acid Bacteria and Detection Biogenic Amines in Food

Author: MengTian
Tutor: ChenWei
School: Jiangnan University
Course: Processing and storage of agricultural products
Keywords: Lactic acid bacteria Biogenic amines Decarboxylase HPLC PCR
CLC: TS207.3
Type: Master's thesis
Year: 2010
Downloads: 407
Quote: 1
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Abstract

Biogenic amines microbial decarboxylase produce alkaline low molecular weight organic compounds. The appropriate amount of biogenic amines having certain physiological activity, excessive intake may cause health damage. Have decarboxylase activity of lactic acid bacteria by decarboxylation of amino acids with the potential security risks of biogenic amines. In view of the potential risks caused by lactic acid bacteria produce biogenic amines to food safety, in order to examine the laboratory preserved the safety of probiotic lactic acid bacteria. Laboratory preserved 61 lactic acid bacteria to be tested bacteria, the first differential medium preliminary screening to Spawn amine lactic acid bacteria, then molecular methods to detect and analyze the potential of its spawn amine from the gene level. Finally, the use of reversed-phase high-performance liquid chromatography analysis of biogenic amines in amino acid decarboxylase medium and food matrix generated method and basis for the evaluation of the safety of probiotic lactic acid bacteria to ensure safer used in fermented food. The results are as follows: to produce amine the characteristics of the material, based on lactic acid bacteria and amino acid decarboxylase medium initial screening of 61 strains of lactic acid bacteria Spawn amine. Added to the medium a precursor of amino acids (histidine, tyrosine, ornithine, lysine), induced through the pyridoxal 5'-phosphate decarboxylase activity medium in the barren nutrition under acidic conditions, with biogenic amines can produce alkaline by the indicator color change display results. Initially detected by this method two lactic acid bacteria histidine decarboxylase activity, tyrosine decarboxylase activity in 16 strains of lactic acid bacteria. 61 of lactic acid bacteria are not detected to ornithine, lysine decarboxylase activity. The ratio of the gene sequence have been reported histidine decarboxylase and tyrosine decarboxylase, to use the primer PHDC1/PHDC2 and P1-rev/P2-for 61 Lactobacillus genomic DNA as a template, by polymerase chain reaction ( PCR), amplified three lactic acid bacteria has histidine decarboxylase gene, 22 strains of lactic acid bacteria with tyrosine decarboxylase gene. The amplification products were sequenced for homology analysis, prove its purpose amino acid decarboxylase gene fragment. This method and microbiological assay test results are basically the same PCR method is to detect potential biogenic amines bacteria method is more accurate and reliable than the medium assay. By benzoyl chloride pre-column derivatization reversed-phase HPLC chromatography quantitative analysis of 25 potential to produce biogenic amines in lactic acid bacteria. The regression equation was four biogenic amines: Histamine: y = 44859x 51524; the Tyramine; y = 52478x 70.76 thousand; the Putrescine; y = 63114x 65892; cadaverine; y = 76449x 31 781. 1-50mg / L concentration range R2 are greater than 0.995, histamine and tyramine, a detection limit of 0.08mg / L, putrescine and cadaverine detection limit of 0.10mg / L. This method is good stability, high precision and recovery. HPLC analysis 25 of biogenic amines to produce lactic acid bacteria in the liquid decarboxylase medium and the four kinds of fermented food systems (fermented milk, fermented White juice, fermented grape juice, fermented meat emulsion) produced histamine, tyramine, putrescine, cadaverine amine situation. The results showed three histamine produces the extreme suitable lactic acid bacteria produce biogenic amines decarboxylase culture bacteria produce histamine amount for 6.99mg/L-69.46mg/L 22 strains of tyramine bacteria can produce tyramine The amount of 4.06mg/L-70.10mg/L. Four food system, the the biogenic amines lowest 25 lactic acid bacteria in fermented milk, the highest no more than 4mg / L. Fermented vegetables, fermented grapes, fermentation the minced meat tyramine levels were lower than 20mg / L, histamine content were lower than 6mg / L. This is far below the U.S. FDA regulations food tyramine content of less than 100mg / L, and histamine content of less than 50mg / L limit standard requirements.

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