利用监测CO2方法预警储藏玉米中黄曲霉菌产毒

Early Detection of Aflatoxin B1 Contamination in Stored Corn by Monitoring CO2 Concentration

摘要:

本文研究了玉米储藏期间真菌产生二氧化碳(CO2)气体的特点，试验结果表明，当灰绿曲霉等干生性真菌生长时，储藏容器中CO2浓度恒速升高；具有快速生长或产毒特点的真菌生长时则出现CO2产气率加速的过程，如玉米中以黄曲霉菌为优势菌时，储藏10 d后产生CO2气体的速率提高4.6倍。进一步研究玉米储藏期间不同原始优势菌、不同真菌生长速率及温度对产生CO2的影响，结果表明，在不同原始优势菌的玉米中均可出现黄曲霉菌的生长和产毒，黄曲霉菌为原始优势菌的AFB1产生量比其他试验组高3~7倍，它们均表现产气速率加速的特征；真菌生长速率及温度可影响储藏玉米中CO2和AFB1的产生量，但在产生AFB1的玉米中，均有CO2产气速率加速的现象。将储藏玉米中CO2产气速率变化与检出AFB1的时间相比，发现前者可提前7 d以上。因此，利用玉米储藏中真菌产生CO2的特征可预警黄曲霉毒素的污染。

Abstract:

The characteristics of carbon dioxide (CO2) produced by fungi during corn storage were investigated. The results showed that CO2 concentration was elevated at a constant rate in the storage container upon development of xerophilic Aspergillus glaucus. The CO2 gas production rate accelerated upon development of fungi that show rapid growth and/or are toxigenic. For example, the CO2 gas production rate increased by 4.6 times after 10-day storage when A. flavus was the dominant fungus in the corn sample. Furthermore, the effects of the original dominant fungal groups, fungal growth rate, and storage temperature on CO2 gas production were evaluated during corn storage. The results showed that A. flavus could develop and produce aflatoxin B1 (AFB1) in corn samples with different original dominant fungi. AFB1 production of the group with A. flavus as the original dominant fungus was three to seven times higher than that of the other experimental groups, and showed an accelerated CO2 production rate. The production of CO2 gas and AFB1 was significantly affected by fungal growth rate and storage temperature, but the CO2 gas production rate increased in all corn samples contaminated with AFB1. Changes in the CO2 gas production rate occurred more than seven days earlier than when AFB1 could first be detected. Therefore, monitoring of the CO2 gas production rate can be used as an early warning of AFB1 contamination during corn storage.