Detection of Molasses-Spirit in Rice-Spirits from TK-8 and TCS-10 by SNIF-NMR Method
CHANG-WEI HSIEH1, HSIU-JU WANG2, CHIEH-MING CHANG3 AND WEN-CHING KO4*
1. Department of Bioresources, Da Yeh University, 112 Shanjiau Rd., Dahtsuen Township, Changhwa County 515, Taiwan, R.O.C.
2. Department of Food Science, National Chung Hsing University, 250 Kuokuang Rd., Taichung City 402, Taiwan, R.O.C.
3. Department of Chemical Engineering, National Chung Hsing University, 250 Kuokuang Rd., Taichung City 402, Taiwan, R.O.C.
4. Department of Bioindustry Technology, Da Yeh University, 112 Shanjiau Rd., Dahtsuen Township, Changhwa County 515, Taiwan, R.O.C.
(Received: December 6, 2004; Accepted: March 15, 2005)
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)I linearly (R2 > 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.
Key words: rice-spirit, ethyl alcohol, deuterium, SNIF-NMR