Supercritical fluid extraction of Aroma-producing and Flavoring Substances in Jiuhuang Water
Supercritical Co2 fluid extractiontechnology is a new material extraction technology developed in recent years.By adjusting the pressure and temperature of supercritical fluid, it cancontrol the two parameters of gas concentration and steam pressure to achievethe purpose of material separation. Supercritical CO2 was used to extractaromatic substances from liquor yellow water. There were more acid substancesin the extract. The effect of supercritical CO2 on liquor blending was obvious.Compared with the traditional methods, the utilization rate of yellow water issignificantly improved.
Liquor is a distilled liquor peculiar toChina. It is one of the eight distilled liquors in the world (Brandy, Whisky,Vodka, Gin, Rum, Tequila, Sake, Spirit), which are made from starch or sugarand distilled after fermentation.
Jiuhuang Water is a by-product of thefermentation of Luzhou-flavor Daqu liquor. It contains abundant organicsubstances and aromatic substances. After special technology extraction, yellowliquor can be used as liquor flavor. It can raise low-grade liquor to the levelof high-quality liquor and bring considerable economic benefits to the liquorindustry.
The quality rate of Luzhou-flavor Daquliquor in China is very low, generally below 40%. The yearly production ofliquor yellow water in national distilleries is very huge. Because liquoryellow water has the characteristics of high acid, high BOD and high COD value,if it is discharged directly, the pollution caused by liquor yellow water willbe very serious. In addition, liquor yellow water contains a variety of activeingredients, which is a kind of available resources. Therefore, it isparticularly important to actively find effective ways to treat liquor yellowwater.
There are many aromatic substances such asacids, esters, alcohols, aldehydes and so on in Jiuhuang water, especiallyabundant organic acids. But Jiuhuang water has more impurities, and containsmore protein, autolysate and pectin. Therefore, it is usually decolorized andfiltered to produce acid condiment of liquor yellow water. In addition, a tailextractor was used to distill yellow water at atmospheric pressure and extractit in two stages to produce low-alcohol yellow water wine. This yellow waterwine has a high content of ethyl lactate and a slightly astringent taste. Butit can be used to blend medium and low-grade liquor to reduce the alcoholtaste. However, these traditional physical and chemical treatment methods canonly recover the low boiling point substances in liquor yellow water, resultingin a great waste of resources, and can not completely solve the bitterness,strange and miscellaneous taste of liquor yellow water.
We have carried out in-depth pilot-scale andpilot-scale studies on supercritical CO2 extraction of yellow water. A newindustrialized way of deep comprehensive utilization of liquor yellow water, aby-product of liquor fermentation, was designed and developed. The extractionof flavor compounds from liquor yellow water by supercritical CO2 has beenstudied systematically and experimentally. Firstly, liquor yellow water wasclarified. On the basis of laboratory experiments, the effects of extractiontemperature, extraction pressure, CO2 flow rate and liquor yellow water flowrate on extraction rate were studied. Taking yield and taste as evaluationcriteria, the pilot-scale extraction process of yellow rice wine was studied.Finally, according to the determined optimum overall technological conditionsfor the extraction of liquor yellow water, the overall industrializationprocess of liquor yellow water production was designed.