Identification of polyphenol extracts from flaxseed and study on its bacteriostatic mechanism

In this paper, the polyphenol components of flaxseed were identified, and their antibacterial effect and mechanism of action against pathogenic bacteria were studied. Results showed that 14 phenolic acids and 15 flavonoids were identified in flaxseed. Among them, 5 phenolic acids, including ferulic acid, vanillic acid, sinapic acid, gallic acid, 4-hydroxybenzoic acid, as well as 6 flavonoids, including vitexin, quercitrin, quercetin, apigenin, kaempfero1, (+)-dihydroquercetin, were the main phenolic compounds in flaxseed and have been quantitatively analyzed and determined. The content of sinapic acid and quercetin accounted for over 42.67% of flaxseed polyphenol extract. The Oxford Cup method confirmed the antibacterial effect of flaxseed polyphenol extract on Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Salmonella and Pseudomonas fluorescens. The experimental data showed that flaxseed polyphenol extract had a strong inhibitory effect on the growth of both common food-borne pathogens and non-food-borne pathogens. Flaxseed polyphenols increased the permeability of microbial cell membrane, resulting in microbial protein leakage, cell membrane depolarization, and decreased intracellular ATP content, and increased cell membrane potential and cell contents leakage. The results of this study clarified the composition of flaxseed polyphenol and provided a new way for the comprehensive utilization of flaxseed.