双孢蘑菇废弃菇柄核酸酶解及5’-核苷酸稳定性

Nucleic acid hydrolyze technology and 5'-nucleotides stability of Agaricus bisporus waste stipe

为了提高双孢蘑菇废弃菇柄5’-核苷酸得率,增加其经济价值。以双孢蘑菇废弃菇柄为原料,首先通过单因素试验研究了pH值、酶底比、酶解温度、酶解时间对5’-核苷酸酶解得率的影响,并采用正交试验分析对5’-磷酸二酯酶对核酸的酶解条件进行优化;其次对双孢蘑菇废弃菇柄浸提液中5’-核苷酸在不同pH值、温度和加热时间下的稳定性进行了研究。结果表明,在单因素试验结果基础上,采用正交试验分析对主要酶解参数进行优化,得到双孢蘑菇废弃菇柄核酸酶解的最优参数为：pH5.0、酶底比3000 U/g、酶解温度50℃、酶解时间3 h,5’-核苷酸得率为1.60 g/100 g。通过稳定性试验发现,双孢蘑菇废弃菇柄中5’-核苷酸在pH值为中性偏酸（pH5~7）条件下比较稳定,受热温度越高5’-核苷酸越不稳定,在试验范围内为保留更多的5’-核苷酸,热处理时间以不超过1.5 h为宜。这一结果可为双孢蘑菇废弃菇柄5’-核苷酸的提取及其在烹调加工中的应用提供依据和指导。

To improve the yield of 5＇-nucleotides, increase the economic value of Agaricus bisporus waste stipe. Nucleic acid, extracted from Agaricus bisporus waste stipe, was hydrolyzed by 5＇-phosphodiesterase（5＇-PDE） to produce 5＇-nucleotides. Firstly, the effects of pH value, ratio of enzyme to substrate, temperature and enzymatic time on the yield of 5＇-nucleotides were investigated by single factor experiments, and optimized the parameters by orthogonal tests. Secondly, the effects of pH value, temperature and heat treat time on the stability of 5＇-nucleotides extracted from Agaricus bisporus waste stipe were also studied. The results showed that on the basis of single factor experiments, the parameters of 5＇-PDE to hydrolyze nucleic acid to 5＇-nucleotides optimized by orthogonal tests are as follows： pH5.0, ratio of enzyme to substrate 3000 U/g, temperature 50 ℃, enzymatic time 3 h. Under these optimum conditions, the yield of 5＇-nucleotides extracted from Agaricus bisporus waste stipe is 1.60 g/100 g. The stability tests showed that 5＇-nucleotides extracted from Agaricus bisporus waste stipe is much more stable at pH5～7, and the higher heat temperature the more loss of 5＇-nucleotides. To retain more 5＇-nucleotides of Agaricus bisporus waste stipe in experiment range, no more than 1.5 h is the preferred heat time. The results could provide guidance for the extraction of 5＇-nucleotides from Agaricus bisporus waste stipe and the application of 5＇-nucleotides in cooking.