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

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 °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 °C and containing 10 and 20 wt% ribose, respectively, after sample immersion in water. Heat treatment at 110 °C, along with glycerol addition, resulted in a decrease of solubility (from 100 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 µg/mL).