Functional prebiotic activity of inulin and fructooligosaccharides

Fructooligosaccharides (FOS) consisted of 2-5 molecules of fructose and one molecule of glucose whereas inulin contained more than 5 molecules of fructose and one molecule of glucose at the reducing end. They are widely used in food industry as the prebiotic. The prebiotics stability is desirable to maintain their functional property. The stabilities of the synthesized prebiotic fructooligosaccharides (FOS) and extracted inulin from Jerusalem artichoke in the simulated processing conditions were determined using a prebiotic activity assay. The prebiotic activity scores were determined based on the change in cell biomass of Lactobacillus acidophilus TISTR1338 on the prebiotic relative to that of Escherichia coli TISTR 780 under the same processing conditions. The tested synthesized FOS were rather unstable. Also, it showed the reduction in prebiotic activity scores after exposure to high temperature (85°C) at all acidic pH levels. The extracted inulins were considered functionally stable in all tested processing conditions. This study presents the stability of the synthesized FOS and the extracted inulin under different simulated processing conditions to provide a better selection of prebiotics in different food applications.