- 期刊
應用螢光影像檢測有無黃麴毒素
Application of Fluorescent Image on Detection of Aflatoxin
摘要
台灣氣候高溫多溼，農產品及食品保存不當時易生黴菌，進而引發黃麴毒素，危害人類及動物的健康。本研究利用螢光顯微鏡搭配三種不同的濾鏡（代號U、G、GFP），針對PDA培養基培養含有黃麴毒素之黃麴菌(A. flavus)與另外兩種無產生黃麴毒素的黑麴菌(A. niger)及米麴菌(A. oryzae)，拍攝其載玻片影像，結果顯示在U及GFP波段比G波段，黃麴菌影像顯示較強螢光反應，另兩種菌則皆無螢光反應。樣本經利用ELISA檢測，呈色結果顯示黃麴菌會產生黃麴毒素，其它兩種則沒有。將三種菌種的影像，擷取其RGB色層上強度分佈平均值進行鄧氏多變域檢定，結果顯示在U波段及GFP波段之彩色影像R、G、B三色層與G波段的R色層，黃麴菌與另外兩菌種有顯著差異，分屬不同組別，代表黃麴毒素會產生較強螢光，且與其它兩種菌有顯著差異。經擷取影像在RGB及HIS色層上強度分佈特徵值，並利用特徵單純值（模式1）及特徵比較值（模式2），代入線性判別分析該樣本是否產生黃麴毒素，當使用18個特徵值時，模式2可得到較高的判別正確率，在測試組判別正確率為82.67%。另外，ELISA分析儀所測得吸光值與毒素濃度有呈反向的關係，當以四參數非線性模式建立其迴歸方程式時，可達R^2=0.98。
並列摘要
The climate in Taiwan is hot and humid, causing crops and foods to be contaminated by mold that generates Aflatoxin-affecting human and animal health. This study applied a fluorescence image technique to detect the Aflatoxin from A. flavus, A. niger and A. oryzae. These types of Aspergillus were cultured on PDA medium before samples of slide culture and solution were made. Fluorescent images were captured by a microscope with U, G, and PFG filters. The histogram of the images was compared on the RGB color plane and the resulting intensity showed significant difference (α=0.05) with U and GFP filters as well as on the R color plane with the G filter. This result indicated that A. flavus had stronger fluorescent intensity than A. niger and A. oryzae. Eighteen features were extracted from the histogram on the RGB and HIS color planes for slide culture samples. These features were analyzed by Linear Discriminant Analysis to classify the types of samples. Results showed that the highest accuracy was 82.67 % in classification of A. flavus with A. niger and A. oryzae. Two commercialized products, ELISA test kits and ELISA readers, were also used to study the Aflatoxin concentration of the samples. Response curves suggested by the ELISA reader demonstrated that the absorbance had a negative correlation with the Aflatoxin concentration. When a non-linear 4-parameter model was used, the R2 reached to 0.98.