Effect of gelatin concentration, ribose and glycerol additions on the electrospinning process and physicochemical properties of gelatin nanofibers

Abstract

Rheological properties of gelatin-based solutions containing different concentrations of ribose and/or glycerol were assessed before electrospun mats were manufactured and their properties investigated. Characterization included morphology, X-ray diffraction, Fourier transform infrared, solubility, swelling, the release of Maillard reaction (MR) products and their antioxidant activity. Gelatin concentrations >= 16 % w/v favoured the formation of smooth nanofibres in the electrospinning process due to their higher viscosity than for gelatin concentrations <= 14 % w/v. The diameters of the nanofibres were between 300 and 400 nm, irrespective of the concentration of gelatin and the additives. Heat treatments (80-110 degrees C) of the samples induced MR between gelatin and ribose, which provided the mats with water stability. Nevertheless, the fibrous morphology only remained for those mats heat-treated at 110 and 100 degrees C and containing 10 and 20 wt% ribose, respectively, after sample immersion in water. Heat treatment at 110 degrees C, along with glycerol addition, resulted in a decrease of solubility (from 100 to similar to 9 %) and provided a water absorption capacity (1,500-2,500 %), due to the crosslinking of ribose and glycerol with gelatin. Release of MR antioxidant compounds from the mats into water exhibited DPPH radical scavenging activity values up to 38 % (0.61 GAE mu g/mL).