Kachouri Faten, Ksontini Hamida, Hamdi Moktar
Laboratory of Microbial Ecology and Technology (LETMI), National Institute of Applied Sciences and Technology (INSAT), BP: 676. 1080, Tunis, Tunisia; Superior School of Food Industry at Tunis (ESIAT), 58 Street Alain Savary, 1003, Tunis, Tunisia.
J Food Prot. 2014 Oct;77(10):1760-7. doi: 10.4315/0362-028X.JFP-13-360.
Olives can be contaminated with a wide variety of molds (Aspergillus and/or Penicillium) that can be occurring naturally on fresh and processed olives and could support mycotoxin production. The aim of this work was to investigate aflatoxin B1 (AFB1) production by fungi and its bioaccumulation in olives during storage and to study the impact of the application of Lactobacillus plantarum on the inhibition of mold development and production of AFB1. Two different treatments were applied: (i) olives with natural microflora and (ii) olives inoculated with Aspergillus flavus after elimination of natural microflora. AFB1 has been extracted from olives and quantitated by high-performance liquid chromatography using a fluorescence detector. Results showed the absence of this metabolite in the olives for the season 2008 to 2009. In 2009 to 2010, AFB1 was detected at the level of 11 μg/kg. The application of L. plantarum during the storage of olives favors the reduction of the level of AFB1 to 5.9 μg/kg correlated with a decrease in the amount of molds (86.3%). The images obtained by environmental scanning electron microscopy showed that L. plantarum was able to adhere to the olive surface and probably produce a biofilm that inhibits the multiplication of yeast and fungi by oxygen competition. Results showed an increase of antioxidant activity and amount of total phenolic compounds of olives, respectively, by 24 and 8.6%. In many olives contaminated with A. flavus, AFB1 was present at an initial level of 5.15 μg/kg and increased to 6.55 μg/kg after 8 days of storage. The biological detoxification of AFB1 in olives by L. plantarum is confirmed by the reduction of the level of AFB1 to 2.12 μg/kg on day 0 and its absence after 4 days of storage.
橄榄可能被多种霉菌（曲霉属和/或青霉属）污染，这些霉菌在新鲜和加工过的橄榄上自然存在，并可能促进霉菌毒素的产生。这项工作的目的是研究储存期间真菌产生黄曲霉毒素B1（AFB1）及其在橄榄中的生物积累，并研究植物乳杆菌的应用对抑制霉菌生长和AFB1产生的影响。应用了两种不同的处理方法：（i）带有天然微生物群落的橄榄和（ii）在消除天然微生物群落后接种黄曲霉的橄榄。从橄榄中提取AFB1，并使用荧光检测器通过高效液相色谱法定量。结果显示，在2008年至2009年的橄榄中未检测到这种代谢物。在2009年至2010年，检测到AFB1的含量为11μg/kg。在橄榄储存期间应用植物乳杆菌有利于将AFB1的含量降低至5.9μg/kg，这与霉菌数量的减少（86.3%）相关。通过环境扫描电子显微镜获得的图像显示，植物乳杆菌能够附着在橄榄表面，并可能产生生物膜，通过竞争氧气来抑制酵母和真菌的繁殖。结果显示，橄榄的抗氧化活性和总酚化合物含量分别增加了24%和8.6%。在许多被黄曲霉污染的橄榄中，AFB1的初始含量为5.15μg/kg，储存8天后增加到6.55μg/kg。植物乳杆菌对橄榄中AFB1的生物解毒作用通过在第0天将AFB1的含量降低至2.12μg/kg以及在储存4天后未检测到AFB1得到证实。
