Evaluation of structural, functional, and anti-oxidant potential of differentially extracted polysaccharides from potatoes peels

Potato peel was used for the extraction of three types of polysaccharides (PW, PAL, and PAC) using water, alkaline, and acid treatments, respectively. The structure of the PP polysaccharides was examined by means of Fourier transform infrared spectroscopy (FT-IR) analysis and Gas chromatography-mass spectrometry (GC-MS). The results suggest that the extracted polysaccharides constituted essentially three functional groups: C=O, C-H, and O-H. The polysaccharides were comprised of low proportions of proteins, 17-23% uronic acids, and approximately 70% carbohydrates. PAL, PW, and PAC with molecular weights of 2.25 x 10(3), 2.18 x 10(3), and 1.92 x 10(3) kDa, respectively, were composed of rhamnose, xylose, mannose, arabinose, glucose, and galactose. Functional properties (solubility, oil holding capacity, foaming, and emulsion properties) of these polysaccharides were evaluated. Among three, PAL showed the highest fat-binding capacity which was 7.50 g/g with the solubility of 95.06%. The three polysaccharides possessed appreciable in vitro anti-oxidant (scavenging DPPH and ABTS(+) radicals, chelating ferrous ions, and reducing power) potential. PAL exhibited the strongest reducing power, scavenging activity on DPPH radicals and chelating capability on ferrous ions. PP polysaccharides can be used as promising natural antioxidants in food, pharmaceutical, and cosmetic preparations. (C) 2019 Elsevier B.V. All rights reserved.