黄酒中尿素的吸附去除技术研究

Removal of urea in Chinese rice wine by resin adsorption

黄酒中的氨基甲酸乙酯（Ethyl carbamate，EC）主要是由尿素与乙醇反应产生的，降低尿素的含量对氨基甲酸乙酯的控制具有极其重要的意义。通过筛选获得有效吸附黄酒中尿素的树脂材料，在较优条件下：树脂添加量10％（体积分数），温度40℃，吸附时间24h，不同尿素水平黄酒单次吸附后的尿素去除率在32％～49％。对于尿素浓度较高（大于15mg／L）的黄酒经多次吸附处理后，尿素浓度均能降至4mg／L以下，且吸附后黄酒的基本理化指标和主要风味成分没有显著变化。该技术在不改变黄酒酿造微生物和酿造工艺的情况下，为安全、有效地减除黄酒中的尿素提供了新的途径。

Ethyl carbamate in Chinese rice wine （Huangjiu） is formed mainly by the reaction between urea and ethanol. It is very important to reduce the concentration of urea for EC control. In this work, adsorption materials were screened for removing urea in rice wine, and an adsorption resin with effective adsorption of urea was obtained. The optimized adsorption conditions for the resin were as follows： the addition of resin was 10% （v/v） , the temperature was 40 ℃, the adsorption time was 24 h. Under the treatment conditions, the removal efficiencies of urea were 32% -49% for different samples with different concentration of urea. For the rice wines with higher urea concentration （ 〉 15 mg/L）, the concentration of urea could be reduced to less than 4 mg/L after several adsorption treatments. Moreover, significant changes of main flavor components in the wines were not founded after multi-adsorption treatments. This work provided a safe and effective approach for the removal of urea in Chinese rice wine, without changing the fermentation process and microorganisms.