3.6. Opacity
Visual characteristics of biodegradable films such as gloss, color,
and transparency can affect consumer acceptability and even food
quality. The impact of fatty acids on opacity is shown in Fig. 3. The
color of the PGP film was yellow and the color intensity depended
on film thickness. The addition of fatty acids increased the film
opacity, and the opacity increased significantly (P < 0.05) as fatty
acid level increased. The same trend was observed by This may be attributed to the physical state of the
fatty acid (solid) at room temperature. Perez-Mateos et al. (2009)
stated that sunflower oil caused whiteness in cod gelatin film
due to the light scattering effect of the emulsion. The addition of C16 and C18 to a filmogenic solution of gelatin resulted in opaque
films, whereas the presence of Brazilian elemi had little effect on
opacity