Exploring the prebiotic characteristics of crude polysaccharides from coconut testa flour: A comparative analysis of local cultivar

Abstract

Crude polysaccharides (CPs) of coconut testa flour (CTF) of five local cultivars; Commercial hybrid (COM), Gon Thembili (GT), Ran Thembili (RT), San Ramon (SR), and Tall × Tall (TT) were isolated in this study to examine to evaluate potential prebiotic properties and structural characteristics. The isolated CPs were subjected to FTIR analysis to identify functional groups of biomolecules. Digestibility tests were performed on CPs of different coconut cultivars using artificial human gastric juice. CPs were applied to <i>Lactobacillus</i> sp. and <i>Escherichia coli</i> to evaluate their proliferation <i>in vitro</i>. FTIR results showed that the occurrence of peaks between 1200 cm^-1 - 1000 cm^-1 was indicative of the presence of C-O side groups and C-<i>O</i>-C glycosidic bonds. CPs of all cultivars displayed strong resistance to hydrolysis (94-97 %) by human gastric juice when compared to inulin and fructooligosaccharides (FOS). The higher proliferation of <i>Lactobacillus</i> sp. was detected on all five CPs when compared to that of glucose. The SR cultivar (1.09) showed a higher prebiotic activity score compared to fructooligosaccharides (0.92) and inulin (0.81). These findings suggest that CPs isolated from CTF of local coconut cultivars possess potential prebiotic characteristics that can be used in the preparation of functional foods. Further studies on this aspect are granted to enable the effective use of CTF in promoting human gut health.