不同制曲方式及米曲霉菌种对豆瓣酱制曲效果的比较

Comparison of the Effect of Different Brewing Methods and Strains of Aspergillus oryzae on the Koji Making Process of Broad Bean Koji

摘要:

为探究发酵菌株和制曲方式对豆瓣酱制曲过程的影响，该研究分别将PNM003和沪酿3.042米曲霉应用于豆瓣酱圆盘制曲和传统开放制曲，考察了几种豆瓣曲制曲过程环境因子、微生物数量、酶活性能、理化指标、游离氨基酸和挥发性成分等差异。结果表明，不同制曲方式和不同菌株制曲过程各项指标存在一定差异。与开放制曲相比，圆盘制曲过程具有稳定的物料温度（30.8~34.4℃）和环境湿度（96.0~97.2%rh），能显著提升制曲过程霉菌数量及酶活性能。此外，圆盘制曲条件下，PNM003制备的豆瓣曲的总酸含量更低（1.00 g/100g）、感官品质更优、游离氨基酸风味更协调。挥发性成分分析表明，相同制曲方式下，PNM003制备的豆瓣曲挥发性成分种类（37种、25种）比沪酿3.042（35种、24种）更为丰富。相同菌株时，圆盘豆瓣曲的风味丰富度高于开放制曲，且霉味风味物质数量低于开放制曲。由此可见，相较于开放制曲，圆盘制曲能显著提升豆瓣酱制曲效果，尤其是以PNM003米曲霉为发酵菌种优势更加明显。该研究为优化豆瓣酱生产工艺、提升豆瓣酱品质提供理论依据。

Abstract:

In order to investigate the effects of fermentation strains and the method of making music on the process of bean paste making, the study applied PNM003 and Huniang 3.042 Aspergillus oryzae to the disk fermentation and traditional open fermentation of bean paste, respectively, and examined the differences in environmental factors, microbial counts, enzyme activity, physical and chemical indexes, free amino acids, and volatile compositions of the process of making music in several kinds of bean pastes. The results showed that there were some differences in the indicators of the different types and strains of bean curd-making process. Compared with the open fermentation process, the disk fermentation has stable material temperature (30.8~34.4℃) and environmental humidity (96.0~97.2%rh), which can significantly improve the number of molds and enzyme activity performance in the process. In addition, the total acid content was lower (1.00 g/100g), the sensory quality was better, and the free amino acid flavor was more harmonized in the bean curd prepared by PNM003 under the disk fermentation conditions. The analysis of volatile components showed that, under the same brewing method, the volatile components of bean curd prepared by PNM003 were more abundant (37 kinds, 25 kinds) than those of Huniang 3.042 (35 kinds, 24 kinds). For the same strain, the flavor richness of disk fermentation was higher than that of open fermentation, and the number of musty flavor substances was lower than that of open fermentation. Thus, compared with the open fermentation, disk fermentation can significantly improve the effect of bean paste brewing, especially with PNM003 Aspergillus oryzae as the fermenting strain, the advantage is more obvious. This study provides a theoretical basis for optimizing the production process and improving the quality of bean paste.