專家專欄|黴菌毒素檢測方法比較與高蛋白寵物食品的實務挑戰
黴菌毒素檢測方法比較與高蛋白寵物食品的實務挑戰
黴菌毒素是寵物食品最難察覺且最常見的風險之一¹。對以肉粉、魚粉、內臟粉與油脂為基底的高蛋白及高脂配方而言,樣品基質複雜,極易在檢驗中產生基質效應(訊號抑制/增強)、回收率偏差與儀器汙染,導致「未檢出」或「低估」。因此,方法選擇要與前處理、校正策略同步思考,才能拿到可靠數據。
一、黴菌毒素主流檢測方法
快篩試紙(Lateral Flow Assay, LFA)²:10–20分鐘出結果,適合進料端大量初篩。優點是快速、便宜、易上手。限制在於檢出限較高、通常一次只測單一毒素,遇到高油/高蛋白樣品易受干擾,陽性或臨界值結果應再送實驗室複驗。
酵素結合免疫吸附分析(Enzyme-Linked Immunosorbent Assay, ELISA)³:2–3小時可批量檢測。靈敏度高於快篩、成本可控,適合例行監測,但不同基質色素、油脂與蛋白會影響讀值,需搭配空白和回收試驗。
高效液相層析(High-Performance Liquid Chromatograph, HPLC)⁴:色譜分離搭配光學偵測,對常見的六大黴菌毒素如黃麴毒素(Aflatoxin, AF)、嘔吐毒素(Deoxynivalenol, DON)、OTA(Ochratoxin A, OTA)、玉米赤黴烯酮(Zearalenone, ZEA)、伏馬鐮孢毒素(Fumnonisins, FUM)和T-2毒素(T-2 toxin, T-2)等目標毒素具高準確度,常作為官方或仲裁方法。缺點是前處理繁瑣、技術含量較高、分析時間較ELISA跟快篩試紙所需的時間較長,不適合日常大批樣本。
LC-MS/MS⁵:多毒素一次定量且選擇性與靈敏度最佳的方法,適合成品放行、法規與爭議批確證。惟儀器昂貴、操作專業度高,且高蛋白/高脂樣品若無妥善潔淨化與校正,仍會低估。
二、最新黴菌毒素檢測技術
qPCR⁶:檢測產毒黴菌或產毒基因,用於源頭「是否可能產毒」之預警,不等於毒素含量,仍需化學分析確認。
AI/雲端輔助⁷:用影像/光譜加上機器學習提升快篩判讀客觀性,或建立雲端趨勢預警,目前定位為輔助,關鍵批次仍須確證法背書。
三、高蛋白/高脂基質的三大難點
基質效應⁸:過高的蛋白質和油脂等共萃物抑制或增強目標訊號,導致外標定量失真。
回收率不穩⁹:黴菌毒素可能與蛋白或脂質結合,被部分「鎖住」,造成萃取不足或淨化時流失。
儀器汙染¹⁰:若樣品萃取過程沒處理好,導致脂質殘留在管柱與離子源,會造成靈敏度下滑及保養頻率大增,拖慢實驗室檢驗頻率。
四、分析對策
適合的快篩試紙¹¹:目前市面上已有部分廠牌的快篩試紙已經可快速檢驗高蛋白及高脂的寵物飼料與食品,可作為初步把關用,但目前各國還是以免疫親和管進行前處理後搭配HPLC與LC-MS/MS作為公告方法。
免疫親和管(Immunoaffinity Column, IAC)/固相萃取匣(Solid Phase Extraction, SPE)¹²:IAC對特定毒素選擇性強、背景最乾淨,適合放行與低含量確證,多毒素時可搭配SPE組合。
快速、簡單、便宜、有效、堅固和安全(Quick, Easy, Cheap, Effective, Rugged, and Safe, QuEChERS技術)¹³:以鹽析及有機溶劑快速萃取多毒素,再用分散式SPE去除雜質,對寵糧這類複雜基質可提高純化率。
增強型脂質去除技術(Enhanced Matrix Removal Lipid, EMR-lipid)¹⁴:專門吸附長鏈脂質,顯著降低訊號抑制,提升低濃度檢出能力,減少儀器汙染。
使用內標校正¹⁵:於萃取過程中添加內標,將不同基質造成的誤差進行校正。
五、不同時間點的實務策略
原料端¹⁶:高風險原料(玉米、大豆、馬鈴薯和DDGS等)批批採樣可使用快篩或ELISA初篩,疑似批立刻暫停收貨並送HPLC/LC-MS/MS。
製程端¹⁷:混料後與乾燥後設關鍵點抽檢,一旦毒素波動,追查水活性、庫存輪替與設備清潔。
成品端:使用改良後的IAC前處理或QuEChERS搭配EMR,或搭配內標去進行HPLC或LC-MS/MS檢測⁴,¹⁸,並將每次的數據留存於雲端,可畫出趨勢圖了解每批原物料於不同季節及來源之影響,日後才可更精準地找出黴菌毒素好發之頻率。
六、業者Tips
別把快篩當終點:快篩或ELISA是初步檢測,最終產品與檢驗爭議批務必以HPLC或LC-MS/MS作為最終確證。
高蛋白就要強潔淨:肉粉/高脂樣本優先採用「QuEChERS搭配EMR」或IAC/SPE,並搭配適合的內標。
建立核心毒素資料庫:主要原料一定要至少涵蓋AF和DON,再依原料特性與季節調整檢驗ZEN、FUM、OTA或T-2/HT-2(如DDGS要著重於FUM和ZEN,麥類則以ZEN和T-2為主)。
分級抽驗與趨勢管理:高風險原料「每批」、中風險「每週/每月」、低風險「每季」,並可用趨勢圖監控供應商與季節性變化。
樣本代表性的重要性遠大過於儀器等級:多點混樣、足量採樣比買更貴的儀器更能降低誤判。
資訊透明:可對外釋出第三方報告與方法重點(LOD/LOQ、前處理和校正),強化品牌形象。
結語:在高蛋白/高脂寵糧上,「選對方法」只是起點,唯有把前處理與校正做到位,再結合分層抽驗加上雲端趨勢,才能把看不見的黴菌毒素風險真正壓到最低。
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