The consequence of supplementing with synbiotic systems on free amino acids, free fatty acids, organic acids, and some stability indexes of fermented milk

An investigation on the impacts of different prebiotics (inulin, galactofructose, soy protein isolate (SPI), and spirulina) and co-culturing with Lacticaseibacillus paracasei on the biological metabolites [free amino acids (FAAs), free fatty acids (FFAs), and organic acids] and stability parameters of fermented milk is presented. All fermented milks represented an increased FAA content compared with their milk counterparts, while the synbiotic fermented milk supplemented with galactofructose (YGF) and spirulina (YSP) were more efficient in this regard. The total organic acid content of the samples was not significantly affected by the type of prebiotics, and co-culturing by L. paracasei, YGF and YSP presented a different pattern, with the highest succinic acid (0.77 mM) and oxoglutaric acid (0.27 mM) contents, respectively. The thermal stability of the fermented milks did not change by loading various prebiotics and co-culturing, while the phase, colloidal, mechanical, and shear stability indexes were significantly affected.