Effect of Nanofiltration and Nano Gold Treatment on the Quality of Chinese Liquors

• Main Authors: Yi-Shiang Huang, 黃義翔
• Other Authors: Wen-Ching Ko
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/39595216868986475520

碩士 === 大葉大學 === 生物產業科技學系 === 96 === Chinese liquors are attractive to many consumers in Taiwan due to an abundant and unique flavor. Since joining WTO in 2002, Taiwan government has removed monopoly and approved general industries engaging in manufacture and sale of alcoholic products. For obtaining the competitive advantage in the Chinese liquor market, the study of quality improvement and aging acceleration becomes an interesting subject among enterprises and researchers. Drinking Chinese liquors with excessive concentrations of higher fatty acids and fusel alcohols will cause acute illness, including headaches, nausea, vomiting, clinical depression, and even coma. The content of those components are related to quality of liquors. Furthermore, aging improves the inadequate parts and provides the excellent flavor and taste. For traditionally natural aging methods, time is a requirement so that extra burden is indirectly resulted. In this study, removal effect of higher fatty acids and Fusel alcohol in liquors by nanofiltration with DK and DL membranes, both molecular weight cut-off (MWCO) of 150-300 Da, was determined. The aging effect by immersion nano gold in imitative liquors was also investigated. The results showed that nanofiltration can be an effectively way to remove ethyl palmitate, ethyl oleate, ethyl linoleate and Fusel alcohols from liquors. Rejection rate 100%, 78.2%, 86.4% and 34.2%, respectively, indicated sufficient improvement for quality of liquors. The DK membrane module showed slight better than DL, while as the reference, no any effect was observed by ultrafiltration for both EW and JX membranes module with MWCO of 2,500 and 3,500 Da. Meanwhile, other physicochemical indices including ethanol concentration, ethyl acetate concentration, total acidity, pH value, and refractive index (oBrix) were not significant different in liquor during the nanofiltration processes. On nano gold aging test, 10, 15, and 20 ppm of nano gold at two particle sizes of 14.3-26.2 nm (small particle) and 31.0-38.1 nm (large particle) were immersion in imitative liquors. After reaction at room temperature for 80 days, ethyl acetate effectively increased. The small particle nano gold showed obvious catalytic effect. According to concentration used, 2.2-, 2.8- and 3.2-fold were reached for that of 10, 15, and 20 ppm, respectively. The methyl peak obtained by 1H NMR analysis of sorghum liquor shifted to the left (δ value shifts from 1.06070 to 1.07531). It was a corroborative evidence of nano gold on aging acceleration of liquors. Nanofiltration and nano gold aging are potent technologies for improvement of Chinese liquors. Cost and safety are two factors in practical application. Excellent materials for making nanofiltration membrane and exclusion method for removing nano gold immersed in liquors are principal considerations should be taken in the future.