Ethanol Determination of Some Indonesian Medicines, Beverages and Various Tape Products by Enzymatic Assay

Abstract

Ethanol can be found in various medicines, beverages and also foods products. Enzymatic assay based on oxidation reaction of ethanol catalyzed by alcohol dehydrogenase is among the methods used for ethanol determination. The present study was intended to utilize this enzymatic assay to determine the ethanol content of some liquid medicines, beverages and also various tape products at different fermentation time points. The results of the present study indicate that ethanol content of the liquid medicines and beverages examined in this study were mainly in agreement with the information provided by manufacturer. Furthermore, in this study, the ethanol content of three tape types (black sticky rice, white sticky rice and cassava tuber) during seven days of fermentation were investigated. The ethanol content increased rapidly for the black and white sticky rice tape up to 5 days of fermentation, reached 9.5 and 8.1% (v/v), respectively. The ethanol content of black sticky rice tape remains constant up to the seventh day. However, the ethanol content of white sticky rice tape decreased at the sixth day of fermentation. While for cassava tuber tape, the ethanol content increaseds lowly during the first three days of fermentation and increased rapidly at the fourth day, followed by decrease of the ethanol content at the fifth day. The highest ethanol content of the cassava tuber tape was 4.5% (v/v) at the third day of fermentation