| Summary: | 碩士 === 國立屏東科技大學 === 食品科學系 === 91 === Abstract
Methanol in alcoholic drinks is routinely determined by method such as gas chromatography (GC) and spectrophotometric method. GC method offers a rapid and sensitive method for the detection of methanol, but the equipment is expensive. The spectrophotometric methods each requires oxidation with permanganate not just for oxidation of methanol, that trace elements of permanganate interfere considerably in the assay, therefore, the method is unsuitable to directly detect methanol in fermented fruit wine. This study presented a modification of the permanganate oxidation procedure for assay of methanol. The use of methanol oxidase offers an efficient catalyst for the oxidation of methanol to formaldehyde that with basic fuchsin to produce chromophore for assay methanol of vegetable-fruit juice and alcoholic beverage.
This experiment investigates the optimum condition for assay system of Methanol oxidase (MOX) method including final formation of absorbance from basic fuchsin with formaldehyde, activity of MOX, duration of incubation time and the effect of interfering substance, moreover, to use this method to detect methanol of vegetable-fruit juice and alcoholic beverage. The result showed activity of MOX is inhibited by the low concentration of ethanol that is a competitive inhibitor. Therefore, MOX method is not able to provide a detection of methanol in alcoholic drinks; this method can detect methanol content of vegetable- fruit juice. In the experiment, tomato juice is the highest methanol content in detected fruits juice. Methanol content of another detected juice is in order of papaya ＞carrot ＞watermelon ＞star fruit ＞melon. Nevertheless, aseptic packing juice is none detected for methanol. For the result surmise that the low boiling point of methanol in juice was removed in the food processing or aseptic processing.
Keyword：methanol oxidase , methanol , basic fuchsin , juice
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