黑曲霉发酵液改善上部烟叶风味品质的研究

为降低上部烟叶中的淀粉和蛋白质含量，提高燃吸品质，以黑曲霉（Aspergillus niger）对上部烟叶粉末进行液态发酵，获得产淀粉酶和蛋白酶较高的菌株及发酵条件为黑曲霉h5，接种量5%（V/V）,培养基烟叶添加量3%，初始pH值6.0，培养温度30℃，发酵时间6d。 将所得发酵液与生物酶配制成新型复合改良剂用于上部烟叶的处理，得到最佳作用条件为含水量20%（发酵液添加量50%）,复合酶添加量1 U/g，反应温度40 ℃，反应时间2 h。处理后上部烟叶中淀粉和蛋白降解率分别为24.84%和21.22%，烟叶燃吸品质明显 提升。 进一步研究发现，以湖南B1F烟叶为培养基底物的发酵液对上部烟叶燃吸品质的改善具有更好的效果，且在其他产地和类型 的上部烟叶中具有很好的扩展性。

Flavor improvement of upper tobacco leaves by fermentation broth of Aspergillus niger

To improve the smoking quality of upper tobacco leaves (UTLs), reduce the starch and protein in the upper leaves, the UTL powder was fermented by Aspergillus niger with liquid-state fermentation. The optimum condition for production of amylase and protease was as follows: A. niger h5 strain, inoculum 5% (V/V), tobacco addition in substrate 3%, initial pH 6.0, culture temperature 30 ℃, fermentation time 6 d. The collected fermen- tation broth was prepared for a new quality modifier of UTLs in combination with mixed bio-enzymes. The reaction condition was optimized as fol- lows: moisture 20% (contaiming fermentation broth 50%), compound enzyme content 1 U/g, reaction temperature 40 ℃, time 2 h. The degradation rates of starch and protein in the UTLs after treatment was 24.84% and 21.22%, respectively, the smoking quality was significantly improved. Further research showed that the fermentation broth of Hunan B1F tobacco leaves as the culture substrate had a better effect on the improvement of the smok- ing quality of UTLs, and it had a good expansibility in other areas and types of UTLs.