Table 2.
Collagen films developed from different animal by-product sources.
| Source | Aims | Plasticizers | Method for Film Production |
Results | Reference |
|---|---|---|---|---|---|
| Hidrogel® B50 | Developing edible films from hydrolyzed collagen, sucrose, and cocoa butter | Sucrose | Solvent casting | Sucrose and cocoa butter reduced the TS of films. Plasticizer improved the elongation of the films. Sucrose increased transparency of films while cocoa butter had negative effect on it. Films contain above 17.5% of hydrolyzed collagen had more homogenous surfaces | [82] |
| Bovine hides | Manufacturing collagen films incorporated with laponite® nanoparticles | Glycerol | Casting | Laponite significantly enhanced the surface roughness of the films while other parameters such as thickness, moisture content, gloss, color, transparency, mechanical, and barrier properties remained intact. Nano-bio-composite films showed a lower melting enthalpy than pure collagen films. | [83] |
| Fish skin | Scaling up of collagen and sodium alginate blended films | Glycerol | Casting machine | The addition of sodium alginate enhanced the viscosity, thermal stability, and TS of collagen films, while the elongation, and WVP remained unchanged. Films made from collagen: sodium alginate 10:2 showed the best rheological and physical properties. Collagen/sodium alginate films were successfully scaled up. | [84] |
| Bligon Goatskin | Producing edible films from collagen extracts and glycerol | Glycerol | Solvent casting | Different concentrations of plasticizer, significantly affected the thickness, tensile strength, and elongation of films but had no effect on solubility, WVTR, and water activity of films. Film contain 80% of glycerol (based on collagen) showed the best mechanical and physical properties. | [85] |
| Bovine connective tissue | Effect on different cross-linkers on the barrier properties of collagen films | Lecithin | Solvent casting for chemically modified films and extrusion for thermally modified films | Thermal cross-linking significantly improved the water resistance of collagen film (up to 70% after 2 h at 80 °C). However, chemical cross-linking with glutaraldehyde, glyoxal, and/or formaldehyde (10% w/w of collagen dry matter) leads to highest water resistance (100% after 2 h at 80 °C). Chemical cross linking reduced the degradation rate of films (90% degradability at 58 °C during 38 days). | [86] |
| Cow’s hide | Effect of apatite reinforcement on physical properties of collagen film | Glycerol | Solvent casting | Apatite particles presented in surface of the film and also increased the compactness of inner side of films with less porous compared to pure collagen film. Incorporation of Apatite significantly enhanced the TS and reduced WVP of films. Apatite decreased the solubility and enhanced the thermal stability of collagen fiber films. | [87] |
| Tilapia skin collagen | Developing blended collagen films with Pachyrhizus starch or rambutan peel phenolics | Glycerol | Solvent casting | The addition of starch and phenolics significantly increased the opacity and thickness of films while water solubility, EAB, and WVP reduced. Highest TS observed for collagen film loaded with 10% starch and 0.5% phenolics. Thermal stability of collagen improved by modification of films and SEM analysis showed a more smooth, uniform, and dense surface for composite films. | [88] |
| Trimmed skin waste from leather industry | Producing blended films from collagen, starch, and soy protein | - | Solvent casting | TS of collagen films increased as the concentration of starch increased, while EAB of films increased by the increase in soy protein in formulation. Hybrid films showed moderately higher thermal stability. SEM images revealed smoother surface for starch-loaded films; soy protein increased the roughness. Hybrid films showed an increase in swelling and in vitro biodegradation compared to pure collagen films. | [89] |
| - | Developing blended films from collagen, methylcellulose, and whey protein | Glycerol | Solvent casting | Collagen films showed the highest EAB (101.4%) and addition of methylcellulose improved technological properties of films such as TS, barrier, and thermal properties of collagen and whey protein films. | [90] |
| Bovine hides | Preparation collagen-2 hydroxyethyl cellulose hybrid films | - | Solvent casting | Cross-linking with cellulose derivatives improved the TS of dry collagen films (22 to 58.9 MPa) compared to pure collagen. Hydrated films showed lower TS and higher EAB compared to dry hybrid films. Cross-linking improved the thermal stability of films. The presence of cellulose improved the bio-stability and biocompatibility of the films with a controlled degradation compared to pure collagen film. | [91] |
| Bovine skin splits | Manufacturing collagen films incoprorated with carboxylated cellulose nanofibers (CNF) | Glycerol | Solvent casting | CNF increased the collagen fibers suspensions and TS of collagen films while EAB reduced. WVP and oxygen permeability of CNF loaded films significantly improved. Microstructure analysis showed that CNF homogenously embedded into collagen fiber matrix and increased the thickness, opacity, and swelling of films. | [92] |