Novel insight into valorization of potato peel biomass into type III resistant starch and maltooligosaccharide molecules

Abstract

Food processing activities in the potato industry generate potato peel in huge quantities. Potato peel residual biomass is rich in biomolecules with high added value. In the present study, the carbohydrate macromolecule, starch, was extracted from the potato peel, followed by enzymatic debranching by employing type 1 pullulanase, Pul M . The retrogradation of debranched starch resulted in the production of type III resistant starch (RS3). The structural details of the granular and debranched starch samples were investigated by scanning electron microscopy. The yield of about 45% RS3 was achieved from the caloric starch obtained from potato peel. The remaining digestible proportion of the peel starch was used for making the preparation of maltooligosaccharides. The chemical composition of native and resistant starch samples was studied by FTIR. XRD profiling confirmed increased crystallinity of peel starch derived RS3 as compared to the native starch. Furthermore, RS3 exhibited higher thermal stability and remarkable resistance against α -amylase digestion than its native counterpart. The bioprocess developed in the present study can be used as an alternative technology to valorize potato peel into functional bio-products. • Granular starch was extracted from potato peel biomass. • Debranching and retrogradation of peel starch resulted biosynthesis of type III resistant (RS3). • The yield of about 45% RS3 was achieved from the peel starch. • RS3 exhibited increased crystallinity, and higher thermal stability. • RS3 showed remarkable resistance against α -amylase digestion.