窖泥指标分析与质量评价机制研究

Index Analysis and Quality Evaluation System of Pit Mud

为深入研究窖泥的感官、理化指标与浓香型白酒质量的相关性,对46家白酒企业窖泥进行了系统分析,并采用理化分析及产酸能力检测指标反映窖泥梭菌数量及窖泥质量。通过系统分析,发现窖泥水分含量30%以上的占比76%,pH值在5.5以上的占比78.46%,93%的窖泥氨态氮含量大于80 mg/100 mg干土,89%的窖泥腐殖质含量在2%以上,84.78%的窖泥产酸能力大于100 mg/100 mL培养液。通过对窖泥产酸能力和窖泥中梭菌菌数进行分析,表明窖泥产酸能力和其中所含梭菌数量呈正相关性,并且随着窖泥产酸能力越强,原酒中己酸乙酯越高,乙酸乙酯和乳酸乙酯比例越低,浓香型白酒风格更典型。本文通过对窖泥产酸能力测定,结合窖泥理化指标,建立了窖泥感官、理化及产酸能力相结合的质量评价体系,此方法成本低、操作简单、结果可靠,适用于白酒企业窖泥质量的检测,有利于提高浓香型白酒的质量。

In order to study the correlation between the sensory and physicochemical indexes of pit mud and the quality of Nongxiang Baijiu,we conducted a systematic analysis of pit mud from 46 distilleries,and adopted physicochemical indexes and acid-producing capacity to reflect the number of Clostridium strains in pit mud and the quality of pit mud.Through systematic analysis,it was found that 76%of the pit mud samples had a moisture content of more than 30%,78.46%had a pH value of above 5.5,93%had an ammonium nitrogen content of more than 80 mg/100 mg dry soil,89%had a humus content of above 2%,and 84.78%had an acid-producing capacity of greater than 100 mg/100 mL.Analysis of the acid-producing capacity of pit mud and the number of Clostridium strains in pit mud showed that there was a positive correlation between the acid-producing capacity of pit mud and the number of Clostridium strains in it.As the acid-producing capacity of pit mud increased,the content of ethyl caproate in base liquor was higher,while the content of ethyl acetate and ethyl lactate was lower,and the style of Nongxiang Baijiu was more typical.Through measuring the acid-producing capacity of pit mud and analyzing the physicochemical indexes of pit mud,we established a pit mud quality evaluation system combining sensory indexes,physicochemical indexes and acid-producing capacity of pit mud.The method has the advantages of low cost,simple operation and reliable results,which is suitable for the detection of pit mud quality in distilleries,and is helpful to improving the quality of Nongxiang Baijiu.