Large-scale extraction of rhamnogalacturonan I from industrial potato waste

Abstract: Potato pulp is rich in dietary fibres and is an underutilised material produced in large quantities by the potato starch factories. Potato fibres are especially rich in rhamnogalacturonan I (RG I). RG I is a pectic polysaccharide with a high degree of branching and until now undegraded RG I has only been extracted in small amounts limiting the application possibilities for RG I. The present paper describes a large-scale extraction process providing large quantities of undegraded RG I readily available. The extraction process includes enzymatic starch removal using purified Termamyl, enzymatic RG I solubilisation using a highly purified polygalacturonase, and finally purification using depth filtration and ultrafiltration. The extracted RG I has a high molecular weight and a monosaccharide composition comparable to RG I extracted by analytical extraction procedures. The large amount of RG I available by the presented method allows for thorough structure–function analyses and tailoring of RG I to specific functionalities. [Copyright &y& Elsevier]