Use of beef, pork and fish gelatin sources in the manufacture of films and assessment of their composition and mechanical properties

This study investigated the properties of different types of gelatin films from solutions of varying gelatin concentrations (4–8 wt %). Gelatin derived from beef, pork and fish skin sources was used to manufacture films using a casting approach. Mechanical properties of gelatin films, water vapour permeability (WVP), oxygen permeability, oil permeability and aqueous solubility of films were evaluated. FTIR spectroscopy was utilized to assess the composition of various gelatin sources so as to determine differences in composition of these sources and ultimately, in overall functionality. High concentration gelatin films had good mechanical properties with tensile and puncture strengths being particularly improved. Gelatin films manufactured from fish skin had the lowest WVP values for each concentration used. All gelatin films possessed excellent barriers to oxygen and oil. Films derived from pork gelatin exhibited lowest water solubility compared to those formed using beef and fish gelatin sources, regardless of the concentrations used. FTIR spectra showed that plasticizer and gelatin were well mixed and interacted well together. The use of higher concentrations of gelatin had the effect of increasing the wavenumber of amide-A in films due to greater interaction occurring between gelatin functional groups.