Characterisation of desolvation-produced high-molecular-weight gelatin fractions and their use for nanoparticles synthesis

Abstract

Gelatins from Tuna (TU) and haddock (HA) skins with well-preserved chains exhibited yields of ∼80-73% and increased aggregation after desolvation to obtain high molecular weight-rich gelatins (TUH and HAH). The results of the oscillatory tests in the linear viscoelastic range at 3 °C indicated that, the gel strength values of tuna gelatin were higher than those of haddock gelatin. The TUH gelatin exhibited similar strength and time stability (frequency dependence) comparing to the corresponding parent gelatin (TU). However, the HAH gelatin showed a less time stability and a lower gel strength, with no gelling and melting transitions. Nanoparticles (NPs) newly prepared by subsequent desolvation step in acetone had very similar average size, PDI and ζ-potential to NPs that were crosslinked with glutaraldehyde. The NPs maintained a similar ζ-potential during storage, while the average size increased progressively after 15 days, particularly in the haddock gelatin NPs. This makes it possible to obtain gelatine NPs with a single desolvation stage, without cross-linking agent, without removal of low molecular weight fractions previously, with potential food and non-food applications from food waste.