The present work aims to optimise chicken skin gelatine/carboxymethyl cellulose (CMC) blended film formulation at varying concentrations of CMC and plasticiser (glycerol). The influence of CMC and plasticiser concentrations on the mechanical (tensile strength, TS and elongation at break, EAB) and physical (water vapour permeability, WVP) properties of chicken skin gelatine films were studied using central composite design (CCD), a full factorial design with all combinations of the factors at two levels (high, +1, and low, −1 levels), with the centre points (coded level 0) repeated thrice. An optimised formulation obtained as a proportional mixture of CMC (3%) and glycerol (0.78%), with tensile strength of 0.08 MPa, elongation at break of 167.57 and water vapour permeability of 6.08 × 10-9 g m-1s-1Pa-1. A formulation with 3% CMC and 0.78% glycerol yielded high TS and EAB, but lower WVP, which is desirable for production of food packaging. This novel research offers the packaging industry an alternative source for producing biodegradable food packaging films which are more cost-effective and at the same time reduce environmental problems.
The aim of this study was to investigate the functional properties of chicken skin gelatin films with varied concentrations of a hydrophilic plasticizer. Gelatin film solutions with different glycerol concentrations A(control), B(5%), C(10%), D(15%) and E(20%), were stirred at 45°C for 20min and oven dried at 45°C. Film characterization determination were included, tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP), solubility, transparency, moisture content, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (X-RD). Glycerol added resulted in improvement of TS and WVP properties. Film B (5% glycerol) demonstrated low EAB (106%), WVP (0.0175 g.mm/h.m2.k.Pa) and solubility (58.64%), but with high TS (3.64 MPa), moisture content (16.0%), UV light transmission (0.04%) and transparency (0.81) compared to films C, D and E. FTIR spectrum analyses demonstrated an aliphatic alcohol group only for Film E (20% glycerol). Hence, chicken skin gelatin film at 5% glycerol concentration showed the most promising potential for industrial food processing applications.