黑曲霉制曲工艺研究

Optimization of Starter-making Conditions of Aspergillus niger

以东北优质粳米为原料,对黑曲霉的制曲工艺进行优化,研究了浸米时间、蒸饭时间、黑曲孢子粉接种量、制曲温度、培养时间对成品黑曲质量的影响。通过单因素与正交实验表明,黑曲霉制曲的最佳条件为:原料粳米浸泡10h,在112℃的条件下,蒸米30min;孢子粉接种量0.35g/kg,制曲温度35℃,培养时间65h。在此培养条件下,成品黑曲外观菌丝稠密,成米粒状,生长结实,表面呈黑色,有黑曲特有的香气,水分为24.4%,糖化力可达840U/g,液化力33.1U/g,果胶酶活力2260.5U/g。

The starter-making conditions of Aspergillus niger are optimized and the effects of rice soaking time,rice steaming time,inoculation quantity,culture temperature and culture time on enzymeactivity are studied.The results indicate that the optimum starter-making conditions are as follows：rice soaking time of 10 h,rice steaming time of 30 min at 112 ℃;inoculation quantity of 0.35 g/kg,culture temperature of 35 ℃,and culture time of 65 h.Under the above conditions,the hyphae of Aspergillus niger koji is dense,strong and the aroma is obvious,the moisture content is 24.4%,the saccharifying power is 840 U/g,the liquefying power is 33.1 U/g,the pectinase activity is 2260.5 U/g.