Chemical characterization of<i>Cassia fistula</i>polysaccharide (CFP) and its potential application as a prebiotic in synbiotic preparation

Abstract

Prebiotics are non-digestible food ingredients that are selectively fermented by probiotics. The aim of this study was to investigate the chemical properties of a polysaccharide extracted from <i>Cassia fistula</i> mature fruit pulp and to evaluate its effects on probiotic strains: <i>L. casei</i>, <i>L. rhamnosus</i>, <i>E. coli</i> Nissle 1917 (EcN), and <i>E. faecalis</i>. These strains were compared for their growth behavior in culture media supplemented with different <i>Cassia fistula</i> polysaccharide (CFP) concentrations. The molecular weight of CFP was approximately 8.707 × 10⁵ Da. The recovered polysaccharide contained a low percentage of crude protein (4.4%). Aspartic acid, glutamic acid, and proline were the most abundant amino acids. Glucose and mannose were the predominant sugars followed by arabinose and rhamnose. <i>L. casei</i> grew faster at high CFP concentrations (2%) compared with the lower concentrations of CFP. The highest values for the prebiotic index and prebiotic activity score were observed for <i>L. casei</i> treated with 2% CFP, and it may be considered a prebiotic due to its high resistance against α-amylase and acidic conditions. CFP provides two ways to adjust nitric oxide (NO) synthesis in macrophages. Finally, the use of 1.5 and 2% CFP for cultured milk production significantly shortened the fermentation period from 210 min to 180 min and 150 min, respectively.