Changes in the Microbial Community and Biogenic Amine Content in Rapeseed Meal during Fermentation with an Antimicrobial Combination of Lactic Acid Bacteria Strains

The aim of this study was to evaluate the microbial changes and biogenic amine (BA) formation in rapeseed meal (RP) during fermentation with a bacterial starter combination of Lactiplantibacillus plantarum-LUHS122 and -LUHS135, Lacticaseibacillus casei-LUHS210, Lentilactobacillus farraginis-LUHS206, Pediococcus acidilactici-LUHS29, and Liquorilactobacillus uvarum-LUHS245. Sampling was carried out after 12 h and 7, 14, 21, and 28 days of cultivation under conditions of constant changes to the substrate, with a change frequency of 12 h. The highest lactic acid bacteria (LAB) and yeast/mould counts were established in RP fermented for 14 days (8.29 and 4.34 log(10) CFU/g, respectively); however, the lowest total enterobacteria count was found in RP fermented for 12 h (3.52 log(10) CFU/g). Further metagenomic analysis showed that Lactobacillus spp. were the most prevalent species in fermented RP. The changes in microbial community in RP led to differences in BA formation. Putrescine and phenylethylamine were found in all fermented RP samples, while the contents of some other amines increased with prolonged fermentation. Finally, the use of combined fermentation could ensure Lactobacillus spp. domination; however, other parameters should be controlled due to the formation of undesirable compounds.

Automated summary

The aim of this study was to evaluate the microbial changes and biogenic amine formation during fermentation of rapeseed meal using a bacterial starter combination. The highest counts of lactic acid bacteria and yeast/mould were observed after 14 days of fermentation, while the lowest total enterobacteria count was found after 12 hours. Lactobacillus spp. were the most prevalent species in the fermented rapeseed meal. The changes in microbial community led to differences in biogenic amine formation.