浓香型白酒大曲在发酵和成熟过程中主要功能酶活力分析

为了对浓香型白酒大曲中功能酶系进行深入研究,实验根据大曲制作、发酵与成熟工艺流程,选取10个时间节点的大曲样品,分析曲皮和曲心α-淀粉酶、单宁酶、木聚糖酶和脂肪酶活力及变化规律。结果显示,在进入发酵期后,曲皮中α-淀粉酶活力基本在523.28~765.78 U范围内变化波动;曲心α-淀粉酶活力在曲块发酵期升降变化波动较大,而在成熟期后期基本维持在350 U左右。在整个研究期内,曲皮和曲心单宁酶活力变化规律较为相似,均先迅速升高,后火期达到最大,然后缓慢降低;木聚糖酶活力在曲皮和曲心样品中,都呈现出持续上升至养曲阶段达到最大值(119.72 U和113.70 U)后再下降的趋势;与其它酶相比较,脂肪酶活力在曲皮和曲心中的变化趋势差异较大,其中曲皮脂肪酶活力呈现先升高再降低,再次升高后降低的变化,而曲心中脂肪酶活力则是持续升高至贮藏一个月达到最大(597.50 U)后急剧下降,然后再次缓慢升高的变化规律。针对白酒大曲发酵和成熟过程中主要功能酶活力变化规律的考察,将为高产酶微生物的分离和筛选提供表征性指导作用,同时也将为制曲工艺的改良和加强型特种大曲的研制提供基础数据。

Activities analysis of main functional enzymes from strong-flavour Daqu of Chinese liquor during fermentation and storage stages

In order to deeply research the functional enzymes in strong-falvour Daqu of Chinese liquor, based on the process of production, fermentation and maturation of Daqu, the activities and variation of α-amylase, tannase, xylanase and lipase from samples derived from Daqu chunks' skin and core, were investigated at 10 processing points. The results exhibited that the activities of α-amylase from Qupi fluctuated between 523.28~765.78 U during Daqu fermentation phase. However, after rapid rise and fall at the fermentation stage, the Quxin α-amylase activities maintained about 350 U at the later stage of maturation. There were similar variations of tannase activities between Qupi and Quxin samples with early rapidly increasing up to the highest activities at Houhuo and slowly decreasing later. Both the xylanase activities from Qupi and Quxin samples all increased during the period of Shaping to Yangqu, the highest activities were 119.72 U and 113.70 U, respectively. Then, they decreased at the later maturation phase. Compared with other enzymes, the change trends of lipase activities between Qupi and Quxin were far different from each other. For Qupi samples, lipase activities first increased and then decreased, then increased and decreased later. However, the lipase activities from Quxin samples rapidly decreased after gradually increased to the highest value (597.50 U) at the stage of one-month maturation. After that, a slight increasing of activities was observed. The study on variation of the main enzymatic activities during fermentation and maturation from Daqu of Chinese liquor, would be a kind of guidance for isolation and screening of some special enzyme producers and useful basis for the improvement of Daqu making-process and research of strengthen Daqu.