2-羟丙基-β-环糊精/阿魏酸包合物对熏马肠中阴沟肠杆菌产酪胺的影响机制

Influence of Ferulic Acid Inclusion Complex with 2-Hydroxypropyl-β-Cyclodextrin on Tyramine Production in Smoked Horsemeat Sausage Inoculated with Enterobacter cloacae

制备2-羟丙基-β-环糊精(2-hydroxypropyl-β-cyclodextrin,HP-β-CD)/阿魏酸(ferulic acid,FA)包合物(HP-β-CD/FA),探究其对阴沟肠杆菌(Enterobacter cloaca)L63的pH值、生长量、酪氨酸脱羧酶相关基因表达和酪胺积累的影响,以及对熏马肠中酪胺积累的影响。采用实时荧光定量聚合酶链式反应检测酪氨酸脱羧酶(tyrosine decarboxylase,tdcA)、酪氨酸/酪胺逆向转运体(tyrosine/tyramine antiporter,tyrP)、酪氨酸t-RNA合成酶和Na+/H+逆向转运体基因在酪胺产生途径中的表达水平。此外,采用高效液相色谱法检测酪胺在48 h内的累积水平。结果表明:FA和HP-β-CD/FA包合物在纯菌体系下均能够降低tdcA和tyrP基因的表达(P<0.05),对阴沟肠杆菌L63有较强的抑菌活性,在纯菌体系和熏马肠中均能够抑制pH值升高,同时有效减少酪胺积累,FA包埋后抑制酪胺积累效果更显著(P<0.05)。

This study aimed to prepare an inclusion complex ferulic acid(FA)with 2-hydroxypropyl-β-cyclodextrin(HP-β-CD)and evaluate its effects on the pH,growth,gene expression,and tyramine accumulation in the cultured broth of Enterobacter cloacae L63 and tyramine accumulation in smoked horsemeat sausage inoculated with this strain.Real time-quantitative polymerase chain reaction(qPCR)was used to measure the expression of the tyrosine decarboxylase(tdcA),tyrosine/tyramine antiporter(tyrP),tyrosine t-RNA synthetases(tyrS)and Na+/H+antiporter(nhaC)genes in the tyramineproducing pathway.In addition,high performance liquid chromatography(HPLC)was employed to detect tyramine accumulation during 48 h of culture of Enterobacter cloacae L63.The results showed that FA and its inclusion complex with HP-β-CD reduced the expression of tdcA and tyrP(P<0.05),had a strong antibacterial activity against E.cloacae L63,inhibited the increase in the pH of the cultured broth and smoked horsemeat sausage and reduced tyramine accumulation.The inclusion complex was more effective against tyramine accumulation(P<0.05).