pistachio hull polysaccharides (PHP) was isolated and characterized. The PHP was a heteropolysaccharide mainly contained 75.50% (w/w) total sugar. As determined by GPC analysis, the polysaccharide with a molecular weight of 3.71×10 6 D (83.2%) was the most dominant fraction. Moreover, HPLC analysis indicated that PHP was predominantly composed of xylose, glucose, arabinose, and fructose. FT-IR and NMR analysis also confirmed the results obtained by HPLC and characterized preliminary structure features of the PHP. Functional properties of the PHP including water holding capacity, and oil holding capacity and DPPH radical scavenging ability were significantly higher than inulin used as reference prebiotic ( p 0.01). Furthermore, the PHP remained 94.37% undigested in the simulated digestion process and stimulated the growth of Lactobacillus plantarum PTCC 1896 and Lactobacillus rhamnosus GG and increased the acetate, propionate and butyrate production over inulin in vitro . Effect of PHP on Caenorhabditis elegans longevity was also investigated in vivo . Obtained results showed that the synbiotic combination of PHP and L. plantarum PTCC 1896 increased the lifespan of C. elegans . Totally, this study intrduced the new synbiotic compound which can be used in food and drug industries. Key words: Pistachio hull polysaccharides; Prebiotic; Synbiotic; Caenorhabditis elegans ; Pharmaceutical.
