[en] Various prebiotic hydrolysates were produced starting from sugar beet pulp (SBP) using alternative solution to traditional acidic hydolysis. SBP pectin was first extracted by acid extraction and ethanol precipitation. Then two technics are used to produced pectic oligosaccharides (POS) : enzymatic hydrolysis (EnzPOS : Rapidase Smart (DSM) ; 50°C ; pH 5) and microwaves-assisted hydrolysis (MW1POS : 104°C/10min/pH 7; MW2POS : 110°C/15min/pH 7). Structural characterization of fractions gave rise to different structural profiles between the four products. Moreover, fermentation parameters obtained in-vitro (A, B, Rmax and Tmax) were also characteristic of the fractions and in favor of a tight relationship between POS structure and POS function. Finally, to avoid solvent use, POS production could be envisaged directly on SBP. Avoiding the step of acidic extraction will allow to meet the green chemistry principles.