Structural, functional, and antioxidant properties of water-soluble polysaccharides from potatoes peels

Water-soluble polysaccharides were extracted from potato peel waste (PPW). The structure of the polysaccharides from PPW (PPPW) was examined by means of Fourier transform-infrared spectroscopy (FT-IR) analysis, X-ray diffractometry (XRD) and gas chromatography-mass spectrometry (GC-MS). The results suggest that the extracted polysaccharides form a semi-crystalline polymer constituted essentially of the functional groups CO, CH and OH. Acid hydrolysis of this polymer yielded glucose (76.25%) as the dominant sugar functional properties (water holding capacity: WHC, oil holding capacity: OHC, foaming, and emulsion properties) of this polymer were studied. The PPPW showed interesting water-holding and fat-binding capacities which were 4.097 +/- 0.537 g/g and 4.398 +/- 0.04 g/g, respectively. In addition, it presented good foaming and emulsion properties. The antioxidant activity of this polymer was also studied and revealed that the polysaccharides showed interesting 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity (IC50 PPPW = 11.578 mg/mL), reducing power and beta-carotene bleaching inhibition activities, and also a strong ABTS radical scavenging activity (IC50 (PPPW) = 2 mg/mL). Overall, the results suggest that the polysaccharide is a promising source of natural antioxidants and can be used as additive in food, pharmaceutical and cosmetic preparations. (C) 2016 Elsevier Ltd. All rights reserved.