植物乳杆菌P-8发酵乳的代谢物图谱

发酵乳是由上百种生物分子组成的一个复杂的食品体系,目前没有单一的分析平台能够完整地测定其所有的代谢物。本试验通过监测植物乳杆菌P-8单菌发酵乳和植物乳杆菌P-8与商业发酵剂YC-X11复配发酵乳的发酵特性,采用超高效液相色谱和四极杆飞行时间串联质谱技术结合统计学方法分析发酵乳的代谢物图谱。试验结果表明,植物乳杆菌P-8与商业发酵剂YC-X11复配发酵所需时间为5 h,远远少于植物乳杆菌P-8发酵所需时间(13 h);复配发酵乳活菌数、滴定酸度均显著增加(P<0.05)。通过代谢组学的分析方法,共鉴定出62种代谢物,主要差异代谢物为有机酸(7种)、多肽(4种)、游离氨基酸(4种)、核酸代谢物(4种)和芳香类物质(3种)等。利用代谢组学方法能够对发酵乳代谢物进行鉴定和分析,并作为其潜在的生物标记物。

Metabolites Profile of Fermented Milk with Lactobacillus plantarum P-8

The fermented milk is considered as a complex food system,measurement of all metabolites in fermented milk using a single analytical platform is usually unattainable.Fermented characteristics was investigated,and metabolites profile of Lactobacillus plantarum P-8 in strain-dependent fermentation and co‐fermentation with commercial starters YC-X11 was analyzed by ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF)combined statistical methods.When the single strain of Lactobacillus plantarum P-8 was used in the fermentation,the time to reach the end point was 13 hours.The fermentation time required 5 hours with both Lactobacillus plantarum P-8 and commercial starter YC-X11.During the fermentation process,the bacterial viable counts in different fermented milk significantly increased(P<0.05),and the titratable acidity significantly increased(P<0.05).62 metabolites were determined as the major compounds contributing to the discrimination of fermented milk.The different metabolites between the mixed fermented milk and the fermented milk with Lactobacillus plantarum P-8 were organic acid(7 species),polypeptide(4 species),free amino acid(4 species),nucleic acid metabolites(4 species)and aromatic substance(3 species).Therefore,metabolomic methods can be used to identify and analyze different metabolites in fermented milk,which could serve as potential biomarkers.