添加糖和乳酸菌对东北酸菜发酵效果的影响

Effects of Adding Sucrose and Lactic Acid Bacteria on Fermentation Effect of Northeast Sauerkraut

为明确糖对东北酸菜发酵效果的影响,该研究设置无添加对照、添加糖、添加乳酸菌3个处理,测定酸菜发酵过程中的理化指标及微生物动态。结果表明,添加糖或乳酸菌处理,pH值下降速度显著快于对照。在发酵第12天,添加乳酸菌处理中可溶性糖的下降最为显著。在发酵第6天,与对照相比,添加乳酸菌和糖处理的乳酸菌数量更高。3个处理中添加乳酸菌处理,乳酸增加最为显著,其次是加糖处理;乙酸在对照处理中增加最显著;在所有处理中均检测到丙酸。高通量测序结果表明,发酵体系在门水平上主要包括Firmicutes,Proteobacteria,Bacteroidetes等。在属水平上,主要检测到Lactobacillus,Lactococcus,Enterobacter等。在添加乳酸菌处理中,Lactobacillus是主要菌属;在添加蔗糖处理中,Lactobacillus的相对丰度持续增加,而Enterobacter占有比例较大。上述实验结果显示,加乳酸菌及糖均能使发酵快速进行,乳酸菌与添加糖两种处理比较,添加糖可能会增加肠杆菌的数量,从而降低酸菜成品的安全性。

In order to investigate the effects of sucrose on the fermentation effect of northeast sauerkraut,this study sets up three treatments of without adding(control),adding sucrose and adding lactic acid bacteria to determine the physicochemical indexes and microbial dynamic changes of sauerkraut during fermentation.The results show that the pH values in the treatments of adding sucrose and adding lactic acid bacteria decrease faster than that of the control.On the 12th day of fermentation,the decrease of soluble sucrose in the treatment of adding lactic acid bacteria is the most significant.On the 6th day of fermentation,the number of lactic acid bacteria in the treatments of adding lactic acid bacteria and adding sucrose is higher compared to the control.Among the three treatments,the increase of lactic acid is the most significant in the treatment of adding lactic acid bacteria,followed by the treatment of adding sucrose.The increase of acetic acid is the most significant in the control treatment.Propionic acid is detected in all the treatments.High-throughput sequencing results show that the fermentation systems mainly include Firmicutes,Proteobacteria and Bacteroidetes at the phylum level.At the genus level,Lactobacillus,Lactococcus,Enterobacter and so on are detected.Lactobacillus is the main genus in the treatment of adding lactic acid bacteria.In the treatment of adding sucrose,the relative abundance of Lactobacillus increases continuously,while Enterobacter accounts for a greater proportion.The above experimental results show that the addition of lactic acid bacteria and sucrose could speed up the fermentation.Compared with the addition of lactic acid bacteria and sucrose,the addition of sucrose may increase the number of Enterobacter,thus reducing the safety of sauerkraut products.