Characterization and Testing of a Novel Sprayable Crosslinked Edible Coating Based on Salmon Gelatin

Abstract

The aim of this study was to develop and characterize a sprayable edible coating using salmon gelatin (SG) and its stabilization by photopolymerization using riboflavin (Rf). Suspensions of SG with Rf at pH values of 5.0 and 8.5 were exposed for 2 min to visible light (VL) and ultraviolet (UV) light and further characterized to determine structural changes of the different gelatin formulations. Rheology analysis showed that at pH 5, the loss modulus (G’’) was higher that the storage modulus (G’) for crosslinked samples (VL and UV light). However, at pH 8.5 G’ values increased over G’’, showing a strong crosslinking effect. Interestingly both moduli did not intersect at any point and their maximum values did not change upon cooling with respect to the gelatin suspension without light exposure, demonstrating that triple helix formation was not affected by the reaction. In fact, neither the gelation temperature nor the enthalpy values were significantly affected. Viscosity measurements confirmed the hydrogel formation using VL, showing higher viscosity values after exposure at increasing temperatures. Transmittance (T%) measurements showed an increase in T% in the suspensions after VL exposure, with only a 10% decrease compared to SG without riboflavin. For validation, the coating was sprayed in fresh salmon fillets, showing a 37% delay in spoilage and reduced weight loss. Therefore, photopolymerization of low viscosity gelatins would allow to manage viscoelasticity of the biomaterial stabilizing it as coating and preventing the deterioration of salmon fillets.

Argon and Argon–Oxygen Plasma Surface Modification of Gelatin Nanofibers for Tissue Engineering Applications

“…Three samples were selected in each experiment and the mean values of CA were reported. In general, gelatin has hydrophilic properties, and it displays excellent wettability in comparison with other polymers [ 46 , 47 , 48 , 49 ]. As can be seen in Table 3 , the gelatin nanofiber scaffold had a mean CA of 20.65°.…”

Rheological and Structural Study of Salmon Gelatin with Controlled Molecular Weight

“…This mechanical behavior is interesting since low viscosity and low gelling temperature SG could provide a technological advantage over mammal gelatins at high concentration since it retains a suitable viscosity for applications relevant to foods, pharma, and biomedicine among other application [ 8 , 10 , 53 ]. For example, a novel sprayable photo-sensitive SG-based coating has been recently described by Char et al [ 4 ], where the low viscosity and low gelling temperature of SG allowed the application of this coating under low temperature conditions normally used by the food industry (T < 6 °C), and therefore easing the adoption of this technology by the industry. On the other hand, Zaupa et al [ 10 ] have reported the technical advantages of SG for use with biofabrication purposes over mammal gelatin, where a combination of low gelling temperature, higher molecular mobility (relaxation times T2 by NMR), and lower capacity of SG to thermal inducing random coil to triple helix transformation upon cooling (circular dicroism), resulted in important advantages for tuning the rate of extra cellular matrix remodeling, which is relevant for wound healing treatments and tissue engineering applications.…”

“…Fish skin is known to be a good source of collagen and gelatin [ 1 , 2 , 3 ]. Gelatin, a partially hydrolyzed form of the fibrillar protein of collagen, can be used for the design of multifunctional biomaterials and composites with interesting applications in the food [ 4 ], pharmaceutical, and biomedical industries [ 5 , 6 , 7 , 8 , 9 , 10 ].…”

“…Indeed, low viscosity gelatins have been successfully used in applications that require small-scale constructs with well-defined geometries and tuned structures such as electrospinning [ 15 ], microfluidics, and micropatterning [ 16 , 17 ]. Other applications include sprayable food edible coatings [ 4 ], polymeric scaffolds, and more recently, bio-inks for 3D printing for tissue engineering applications [ 1 , 18 , 19 ]. These examples clearly show some of the advantages in using cold water fish gelatins compared to gelatins from mammal, enabled by its rheological properties, either to the design of novel product or the complex manufacturing processes.…”

Synthesis and Physicochemical Characterization of Undecylenic Acid Grafted to Hyaluronan for Encapsulation of Antioxidants and Chemical Crosslinking

“…Riboflavin was used to eliminate TEMED, as the oxidative system may exhibit toxicity [38]. The addition of riboflavin also formed a network, which could be a sign that crosslinking could be mediated by visible light [39]. Even though, the most homogeneous materials were produced by Irgacure 2959 (Figure 8).…”