Study On The Invasion Of Aspergillus Flavus On Paddy And Its Growth, Detection And Prevention

Paddy, as a kind of vivo seed, some irreversible changes that influence its eating qualitycould happen during the storing. As it well known, there have many external factors can eitherpromote or delay such deterioration. Hence, the study on the stored paddy should be able toprovide some scientific instructions on the related storage. Based on the investigation of onegrain reserve, we employ an artificial climate chamber to simulate the storage of paddy in ourresearch. In that experiment, we study the selection, identification, growth and prevention ofaflatoxin-producing Aspergillus, and the harm caused by the invasion of Aspergillus flavus onthe storage and germination of paddy. Except setting the moisture content of paddy as well asthe temperature and humidity condition of the storage, we are the first to introduce the add-inAspergillus flavus spore’s suspension to analyze its effect on the storage of paddy. Moreover,the SDAPCI-MS is applied for detecting the aflatoxin （AFT） in the stored paddy. Wedemonstrate that the SDAPCI-MS can be a new effective method for detecting the AFT. To bespecific, our contribution goes as follows:1) We investigate the paddy of the state grain reserve located in northern Fuzhou, JiangXi.Based on the result of that investigation, we launch a simulation experiment of paddy storagewith an artificial climate chamber. Influence of various factors, including the differentmoisture content, freshness on the behalf of paddy and the temperature and humidity of thestorage, as well as the manually add-in Aspergillus flavus spore’s suspension, on the quality ofpaddy are analyzed. The experiment shows that the temperature and humidity of the storageplays the key role.2) The AFT ELISA kit is used for analyzing the residual AFT B₁in the samplers from theclimate chamber during the4stages of storage. More precisely, little B₁is detected from thefresh paddy, while some B₁are detected from both the sampler with add-in Aspergillus flavusspore’s suspension and three year aged paddy sampler, among which the highest one reaches 8.1μg/kg. Simultaneously, we also employ SDAPCI-MS to detect the AFT in the paddy’ssurface without any pretreatment. The result demonstrates that SDAPCI-MS is a feasibleapproach to rapid detection of AFT. Considering this, we regard it as a creative idea fornondestructive rapid detecting approach of AFT.3). According to the colonial and morphological characteristics, florescence color,together with differential medium, aflatoxin-producing Aspergillus are selected from thepaddy to derive its growth curve. Meaning while, we also find5botanicals that can restrainthe growth of aflatoxin-producing Aspergillus, among which the cinnamon works the best.Those selected botanicals are likely to be used for preventing the pollution of AFT and mightbe applied to the storage of paddy in the future.4).We analyze the affect of aflatoxin-producing Aspergillus on the paddy during thegermination from the physiological and ecological perspective. The result indicates thatAspergillus flavus is capable of preventing the germination of paddy. If the Aspergillus flavusexist longer, the suppression affect can be more conspicuous.