Fermenting of flaxseed cake with Lactiplantibacillus plantarum K06 to increase its application as food ingredient - The effect on changes in protein and phenolic profiles, cyanogenic glycoside degradation, and functional properties

The aim of the study was to investigate the effect of fermentation of flaxseed cake with Lactiplantibacillus plantarum K06 on its composition (protein and phenolic profiles), functional properties (antioxidative activity, total phenolic content – TPC, water holding capacity – WHC, viscosity), and cyanogenic glucoside (CG) degradation. Samples were analysed during 48 h of fermentation. The 48 h fermentation caused an increase in low molecular weight protein fraction which constituting one-third of the total proteins. Moreover a slight decrease in the secoisolariciresinol diglucoside (SDG) (by 15%) and phenolic acid content (at least 7%) was observed in comparison to unfermented flaxseed cake. The antiradical activity and TPC increased (at 66% and 20% respectively), whereas the WHC and viscosity decreased (by 32% and 52%). Most of the changes occurred after 24 or 36 h of fermentation. Longer fermentation did not significantly influence the parameters. An additional benefit was the complete degradation of CGs after 24 h of fermentation. The experiment showed that fermentation with L. plantarum K06 effectively modified the properties of flaxseed cake, thus increasing its application as a food ingredient.