制曲水分

Moisture Content in Starter-making

水是生命活动的重要成分,微生物的生长离不开水分,在制曲的不同阶段,对水分的要求亦不同。多数制曲水分控制在37%～40%,制曲水分酱香>浓香>清香。曲霉孢子在制曲时要求湿度达到90%,随着发酵时间的延长,曲中水分逐渐下降,到40d时,水分下降到13%左右,微生物数量则有增有减,其中细菌数呈增长势头,从发酵5d的每克曲含菌2.97×106个增至第40天的1.19×109个;酵母菌则从4.05×106个下降到3.5×105个;霉菌菌数则先降后升再降。米曲水分控制在24.4%～33.3%时,生淀粉糖化力随水分增大而加强,其他酶类波动幅度不大。水分过量则对酶的生成不利。各种微生物对水分需要量大小依次为细菌>酵母菌>根霉>曲霉>青霉。(晓)

Water is indispensable to vital activity including microbial growth. In different starter-making stages, the demand of moisture content varied. For most starter-making cases, moisture content be controlled between 37 %～40 % (moisture content in Maotai starter higher than that in Luzhou starter which higher than that in Fen starter). The humidity of aspergillus spore is required to achieve 90 % in starter-making. With the prolong of fermentation time, moisture content in starter gradually decreased, and it decreased to about 13 % 40 d later, however, microbes quantity experienced increasing stage or decreasing stage, bacteria quantity presented increasing trend from 2.97×106 particles (5 d fermentation) to 1.19×109 particles (40 d fermentation), microzyme quantity decreased from 4.05×106 particles to 3.5×105 particles; mildew quantity first decreased then increased and finally decreased. When moisture content in rice starter controlled between 24.4 %～33.3 %, the saccharifying power of crude amylum became stronger with the increase of moisture content, however, only slight changes occurred for other enzymes. Excessive moisture content was harmful for enzyme growth. Water demand for varieties of microbes ranked in decreasing sequence as bacteria, microzyme, rhizopus, aspergillus, and penicillium. (Tran. by YUE Yang)