DETERMINATION OF ALCOHOL CONTENTS OF FERMENTATED BLACK TAPE KETAN BASED ON DIFFERENT FERMENTATION TIME USING SPECIFIC GRAVITY, REFRACTIVE INDEX AND GC-MS METHODS

摘要

Tape ketan is the product of fermentation process using black glutinous riceas basic ingredients, which then fermented for two to three days and finally produced tape ketan, organic acid and alcohol. The purpose of this research was to determine alcohol contents of fermentated black tape ketan based on different fermentation time with three diferent methods. Methods used are specific gravity, refractive index and GC-MS. Alcohol concentration obtained by using specific gravity method at 3, 10, 17, 24, and 31 days of fermentation, respectively, are 3.17% v / v; 3.02% v / v; 3.63% v / v; 3 , 12% v / v; and 4.47% v / v, using the method of refractive index is 3.90% v / v; 3.69% v / v; 4.31% v / v; 3.80% v / v and 5.04% v / v, and using GC-MS method was 4.30 % v/v; 4.23 % v/v; 5.01 % v/v; 4.75 % v/v; and 5.34 % v/v.The variation of fermentation time obviously did not influence the produce of alcohol contents statistically.