來源及儲存對飼料玉米黴菌毒素含量之影響

Effects of sources and storage on contents of mycotoxins in maize

林瑞蓬(Reuy-Perng Lin)

指導教授 ： 林美峰

國立臺灣大學/生物資源暨農學院/動物科學技術學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.10155

摘要

污染飼料的黴菌毒素主要有黃麴毒素（Aflatoxins）、伏馬鐮孢菌毒素（Fumonisins）、嘔吐毒素（Deoxynivalenol）、赭麴毒素（Ochratoxins）、T-2 毒素 （T-2 toxin）及玉米烯酮毒素（Zearalenone），為麴菌 （Aspergillus spp.）、伏馬鐮孢菌（Fusarium spp.）及青黴菌（Penicillium spp.）等真菌之二次代謝物，其污染會影響動物的生產性能和健康，嚴重時甚至導致死亡，部分黴菌毒素也會轉移到乳、肉、蛋等畜產品，成為食品安全問題亦造成嚴重的經濟損失。前人研究顯示黴菌毒素受玉米水分及田間採收到乾燥時間間隔影響，基於以上因素，本研究就進口玉米及國產飼料玉米 2 部分進行 5 個試驗，以了解來源、儲存期間及延遲乾燥對玉米黴菌毒素含量之影響。
結果顯示進口玉米黴菌毒素及營養成分依來源有所不同，所有樣品皆未檢出赭麴毒素，而以 T-2 毒素之檢出率 100 % 最高，其次為嘔吐毒素的 94.8 %。各種黴菌毒素風險較高國家分別為，黃麴毒素以南亞及東南亞國家風險較高，嘔吐毒素為北美洲及非洲，伏馬鐮孢菌毒素為南美洲 B 國，玉米烯酮毒素為東南亞，其中由亞洲進口者須嚴加監控黃麴毒素，205 件玉米樣品中有 6 件超過我國飼料玉米黃麴毒素 50 ppb 限量標準，其中 4 件為南亞樣品另 2 件為東南亞樣品。
不論進口或國產玉米於儲存期間均會增加伏馬鐮孢菌毒素檢出率及部分樣品檢出濃度，水分含量也有上升趨勢。但各項黴菌毒素及一般營養成分於儲存期間檢出值與儲存時間均無顯著相關。國產玉米於儲存期間未檢出赭麴毒素，亦未檢出玉米烯酮毒素。國產飼料玉米如未於採收當天立即烘乾，則被檢出黃麴毒素的機率大幅提高，採收後到乾燥時間（第 2 天到第 4 天，X 日）與黃麴毒素濃度（Y ppb）間，呈顯著一次線性廻歸（Y = 8.53 X - 8.33，R2=0.946，p ＜ 0.0001），但儲存後黃麴毒素濃度變化與時間則無相關，值得生產者注意，尤其是以日曬乾燥者。國產玉米之嘔吐毒素及玉米烯酮毒素平均檢測值及檢出率均較進口玉米低，粗蛋白質及總能之含量為各國之最高，粗纖維含量則最低，顯見國產玉米品質相當良好。
本試驗僅就北美洲進口之玉米進行儲存試驗，且樣品及重複數不大，爾後可再就其他重要進口國之玉米進行研究。田間真菌（field molds）產生之不同黴菌毒素在儲存試驗中出現不同結果，可再進行儲存期間玉米之田間真菌及儲存真菌（storage molds）種類及數量之試驗，將有助於釐清相關變化。

關鍵字

黴菌毒素 ； 進口玉米 ； 國產飼料玉米 ； 儲存 ； 採收 ； 乾燥前

並列摘要

The main mycotoxins in feeds are Aflatoxins ( AF ), Fumonisins ( FSN ), Deoxynivalenol ( DON ), Ochratoxins( OCA ), T-2 toxin and Zearalenone( ZEA ). Mycotoxins are the secondary metabolic products of fungi, such as Aspergillus spp., Fusarium spp. and Penicillium spp. Mycotoxins hazard to animal health and/or performance; especially at high contamination level, reduction on growth and production or increase on mortality will probably occur. The previous studies showed that occurrence of mycotoxins were influenced by moisture contents and interval period from harvest to pre-drying. Thus, this study was conducted with five trials to learn the effects of sources, storage duration and delay-drying on mycotoxins in imported or domestic maize.
The results showed that OCA was not detected in any sample, while only domestic maize was negative of ZEA. Detection rate of T-2 was the highest at 100 %, followed by DON ( 94 % ). Total detection rate of AF was 25.9 % ( 53 / 205 ). The average AF concentration in the maize from South Asia was higher than that from other importing countries. Six samples of AF content above Taiwan’s national standard were from South Asia ( 4 samples ) and Southeast Asia ( 2 samples ). Detection rate of FSN and its concentration in some samples were increased by storage time of maize whether imported or domestic. The AF risk would increase with the time from harvest to pre-drying. AF levels and time （1-3 days） from harvest to pre-drying showed linear regression ( Y = 8.53 X - 8.33, R2 = 0.946, p ＜ 0.0001 ). The detection rates and average detected levels of DON and ZEA in domestic maize were lower than those of imported one. The contents of crude protein and gross energy of domestic maize were higher and crude fiber was lower than those from other countries. which implying that the quality of domestic maize was excellent.
Mycotoxins and nutrients of imported maize differed among the sources. South Asia and Southeast Asia were two areas at high AF risk. Both of North America and Africa were the high risk areas of DON, South America （country B） and Southeast Asia were the areas at high risk of FSN and ZEA, respectively. In this study, only the maize imported from North America was tested for the effects on mycotoxin occurrence and content by storage duration with limited sample size and duplications. It will be expanded to test the maize from other major import countries in the future. Different mycotoxins produced from field molds performed differently during storage, suggesting further study needed on the types and quantity of field molds and storage molds to understand their interaction.

並列關鍵字

mycotoxin ； imported maize ； domestic feed maize ； storage ； harvest ； pre-drying

參考文獻

行政院衛生署。2009。台灣食品中真菌毒素限量標準。

Abbas H. K., R. D. Cartwrightb, W. Xiec and W. T. Shier. 2006. Aflatoxin and fumonisin contamination of corn (maize, Zea mays) hybrids in Arkansas. Crop Protection 25: 1-9.

Abbas H. K., W. T. Shier and R. D. Cartwright. 2007. Effect of temperature, rainfall and planting date on aflatoxin and fumonisin contamination in commercial Bt and non-Bt corn hybrids in Arkansas. Phytoprotection 88: 41-50.

Bhat R., R. V. Rai, and A. A. Karim. 2010. Mycotoxins in Food and Feed: Present status and future concerns. Compr. Rev. Food. Sci. F. 9: 57-81.

Binder E. M., L. M. Tan, L. J. Chin, J. Handl and J. Richard. 2007. Worldwide occurrence of mycotoxins in commodities, feeds and feed ingredients. Anim. Feed Sci. Tech. 137: 265-82.