測定甜味劑阿斯巴甜之酵素感測器   全文下載

Determination of the Sweetener Aspartame with an Enzyme Sensor

本研究開發出一個能有效、簡便地測定食品中阿斯巴甜（aspartame）含量之酵素感測器。所建立之檢測系統係選定由α-chymotrypsin及alcohol oxidase所組成之雙酵素系，利用透析膜包覆法（entrapping）固定後與溶氧電極裝置組合，即可有效完成aspartame之定量工作。此酵素感測器最適操作pH值在6.5至8.5之範圍內，最適操作溫度為30°C，一次分析在10分鐘內完成，可有效測定0.1mM至2mM範圍內之受質濃度。若將此固定化酵素電極保存於dithiothreitol溶液中，操作穩定度可達7天以上，可連續操作70次而不會有活性之降低。以此法對三種不含酒精樣品進行檢測，所得結果與商品標示大致吻合（相對誤差在5%內）。

This study attempted to establish an efficient, convenient enzyme sensor for the determination of aspartame in foodstuff. The sensor system we investigated was a bienzyme system composed of ex-chymotrypsin and alcohol oxidase, immobilized by an entrapping method with dialysis membrane, subsequently combined with the dissolved oxygen electrode equipment. This method was able to determine aspartame efficiently. The optimum operational conditions for the enzyme sensor were pH 6.5~8.5 and 30°C. A linear relationship was observed between D.O. decrease and the aspartame concentrations in the range of 0.1-2mM. One assay could be completed within 10 minutes. When the enzyme electrode was stored in dithiothreitol solution, the system was stable for more than 7 days and 70 assays. When this system was used for the determination of aspartame in commercial non-alcoholic products, the results were found to be in close agreement with the labelled values provided by manufacturer (within 5% of the relative error).