Detection of molasses-spirit in rice-spirits from TK-8 and TCS-10 by SNIF-NMR method

Abstract

The objective of this study was to identify the origin of edible alcohol usually added in Taiwanese rice-spirits by using deuterium nuclear magnetic resonance (SNIF-NMR method). Rice-spirits labeled TK-8, TCS-10 were made from two rice varieties, Taikeng 8 and Taichung sen 10, whereas molasses-spirit labeled MS was obtained from Taiwan Sugar Corporation. The proportion of ethanol molecules monodeuterated on the methyl site (D/H)(I) and methylene site (D/H)(II), and the ratio R between the intensities of methyl and methylene signals in deuterium spectra were significantly different among TK-8, TCS-10, and MS. Of the three indices, only (D/H), linearly (R-2 > 0.96) increased with addition of MS in both TK-8 and TCS-10. Therefore, (D/H)(I) was an index for the identification of pure rice-spirits mixed with ethanol originated from molasses