植物提取物抑制玉米中黄曲霉生长及产毒研究

Inhibitory of the growth of Aspergillus flavus and aflatoxin B_1 in maize by plant extracts

通过液体培养一直接接触法比较植物提取物肉桂醛、柠檬醛和丁香酚对黄曲霉生长及产毒的抑制作用，选取抑制作用最强的肉桂醛应用到玉米中，研究了添加量、玉米水分含量和储藏温度对肉桂醛抑制黄曲霉生长及产毒的影响。结果表明：液体培养基中，肉桂醛、柠檬醛和丁香酚的最低杀菌浓度与各自完全抑制产毒浓度一致，分别为100、500和500μl／L。随着添加量的加大，肉桂醛对黄曲霉生长和产毒的抑制率逐渐升高，挥发浓度为96μl／L时完全抑制黄曲霉生长，对黄曲霉毒素B，的抑制率为97．98％。在玉米水分为14％～40％时，肉桂醛对玉米黄曲霉污染的抑制率随水分含量的升高显著下降，14％时抑制率最高，为88．24％；对黄曲霉毒素B。始终保持较强的抑制作用，14％时产毒抑制率最高，为97．51％。储藏温度在20～37℃时，肉桂醛对黄曲霉污染的抑制率随温度的升高呈现先升高后降低的趋势，28℃黄曲霉污染抑制率最高，为85．67％；对黄曲霉毒素B，抑制率随温度的升高呈现先降低后升高又降低的趋势，20℃时抑制率最高，达到91．00％。

Contact assays method was used to compare three kinds of plant extracts： cinnamaldehyde, citral and eugenol on Aspergillus flavus （A. flavus） growth and aflatoxin B1 （AFB1） production in liquid medium. Cinnamaldehyde was proved to be the most effective,and the effect of adding amount, water content and storage temperature on A. flavus growth and AFB1 production were studied. The results showed： in liquid medium, the minimum bactericidal concentration of einnamaldehyde, citral and eugenol were consistent with their complete inhibition of virus concentration,were 100, 500 and 500μl/L, respective- ly. With the increase of the amount of cinnamaldehyde, the inhibition rate of A. flavus growth and production of AFB1 in- creased gradually, while volatilization concentration of cinnamaldehyde was 96 μl/L, the inhibition rate of AFB1 was 97.98 %, the growth of （A. flavus）was completely inhibited. The inhibition rate of cinnamaldehyde on A. flavus growth decreased with the moisture content（14 % ～ 40 %） significantly increased, was the highest of 88.24% when the moisture content was 14 %. AFB1 production was significantly inhibited, and the inhibition rate 97.51% when the moisture content was 14 %. Storage tem- perature had an impact on the inhibition effect of cinnamicaldehyde at 20～ 37℃. The inhibition rate of cinnamaldehyde on A. flavus growth increased firstly and then decreased with the temperature increased, and the suitable temperature was 28℃ with 85.67 % of reduction. The inhibition rate of cinnamaldehyde on AFB1 production decreased firstly and then increased, and subsequently decreased with the temperature increased. The inhibition rate of cinnamaldehyde on AFB1 production was the highest at 20℃, with 91.00% of reduction.