Effect of natamycin, nisin and glycerol on the physicochemical properties, roughness and hydrophobicity of tapioca starch edible films

• Films based on tapioca starch and with glycerol, nisin and natamycin were studied.
• The content of glycerol affected the mechanical properties, the water vapor permeability and the roughness.
• Nisin adversely altered the mechanical parameters and the color of the films and decreased wettability.
• Natamycin produced a slight reduction in water vapor permeability.
• The water vapor permeability and contact angle were correlated with the roughness of the films.

In this paper, films based on tapioca starch and containing nisin, natamycin and glycerol were characterized in relation to their physicochemical properties, roughness and hydrophobicity. The content of glycerol affected the mechanical properties of the films studied and the roughness and it was observed an increase in WVP with the increase in glycerol content. The addition of antimicrobials affected the mechanical properties, being nisin the one that produced the greater decrease in the Young modulus. The color was highly affected by the joint presence of natamycin and nisin, which increased the yellow index. The contact angle increased with antimicrobial addition indicating a decrease in hydrophilicity. Nisin also affected the roughness of the films. Water vapor permeability was slightly reduced by the presence of natamycin. It was observed that water vapor permeability and contact angle were correlated with the roughness of the films.

Film wettabilities and images of the water droplets deposited on the films with (NA, NANI and NI) and without (CNA, CNANI and CNA) antimicrobials. Film with natamycin (NA), film with natamycin and nisin (NANI) and film with nisin (NI). The symbol C corresponds to their controls.Figure optionsDownload as PowerPoint slide