Gelatin nanofibers: Analysis of triple helix dissociation temperature and cold-water-solubility

Gelatin nanofibrous structures, characterized by high specific surface area and high porosity, have been widely researched for biomedical and food applications. The present paper researches the potential of electrospinning to produce a nanofibrous cold-gelling (or instant) gelatin product. Our results show that gelatin nanofibers are cold-water-soluble due to their high surface-to-volume ratio, facilitating easy water penetration and dissolution, and this for several gelatin types. Additionally, fast gelation after dissolution in cold water indicates that the electrospinning process does not significantly reduce the gelatin molecular weight, nor compromise triple helix formation. These conclusions were supported by thorough investigation of the internal gelatin structure, using a new approach based on modulated temperature scanning calorimetry. Oscillation rheology revealed that the nanofiber-based gels have moduli comparable to powder-based gels. Gelatin nanofibers can thus be used as instant gelatin product, without the drawbacks of traditional amorphous instant gelatins such as sensitivity to moisture, low wettability and low modulus of the cold gel. Using the approach reported here, every electrospinnable, but non-cold-water-soluble gelatin can be transformed into a cold-water-soluble variant, regardless of the type or modification. Electrospinning can thus offer enormous flexibility in materials selection, enabling the production of cold gels loaded with temperature-sensitive components, UV-cross-linkable cold gels, etc. (C) 2016 Elsevier Ltd. All rights reserved.