陈酿白酒中黄色呈色强度快速表征方法的研究

Research on rapid quantitation of the yellow intensity of aged Baijiu

微黄透明是白酒陈酿过程品质提升的重要体现,但目前还缺乏对于陈酿白酒中黄色呈色强度的客观精确表征技术方法。该文基于分光光度法,以焦糖色作为参比,优化建立了一种陈酿白酒中黄色呈色强度的快速精确分析方法。采用单一波长下的分光光度法,优化了酒样浓缩体积(50 mL)以及测量黄色强度的吸光值,使用焦糖建立黄色强度标准曲线,根据标准曲线实现黄色量化表征。结果表明,标准曲线在0~2.5 mg/L内有良好的线性关系,回归方程为y=0.2903 x(R^(2)=0.9999),检出限为3.4μg/L。选取了一种样品6个平行做精准度测验,日内相对标准偏差为1.70%,日间相对标准偏差为3.76%。通过对不同香型以及酱香型不同轮次酒样进行检测,线性拟合了年份酒的黄色物质浓度,用Boltzmann函数拟合了轮次酒的黄色物质浓度,黄色强度值也符合行业对于不同酒样黄色强度的认知。

Yellowish transparency is an important manifestation of the Baijiu quality during aging process,however there is still a lack of objective and accurate technical methods for the characterization of the yellow color intensity in aged Baijiu.In this paper,based on spectrophotometry,taking caramel color as a reference,a rapid and accurate analysis method of yellow color intensity in aged Baijiu was optimized and established.Using spectrophotometry under single wavelength,the concentrated volume of Baijiu samples(50 mL)and the absorbance of measuring yellow intensity were optimized,then a standard curve of yellow intensity was established using caramel tone,finally,the quantitative characterization of yellow color was realized according to the standard curve.The standard curve had a good linear relationship in the range of 0-2.5 mg/L,the regression equation was y=0.2903 x(R^(2)=0.9999),and the detection limit was 3.4μg/L.Six parallel samples of one sample were selected for the accuracy test,with an intra-day relative standard deviation of 1.70%and an inter-day relative standard deviation of 3.76%.Through the detection of different type of aroma and different rounds of soy-sauce-aroma Baijiu samples,the concentration of yellow substances in vintage Baijiu was linearly fitted,and the concentration of yellow substances in rounds of Baijiu was fitted by Boltzmann function.The yellow intensity value is also in line with the industry′s perception of the yellow intensity of different Baijiu samples.