Barrier, Mechanical and Antimicrobial Properties of Yam Starch Film With Cássia Cinnamon Essential Oil and Its Application in Strawberry Storage

Abstract

In recent years, concerns about food safety and the search for natural alternatives for food preservation have driven research and the development of new antimicrobial materials. In this context, this study aimed to develop yam-based films with chitosan and cinnamon essential oil (CEO). The developed films were characterized in terms of mechanical properties, moisture content, water solubility, barrier properties, contact angle, scanning electron microscopy, optical properties and antimicrobial activity. Finally, they were used to evaluate antifungal activity in strawberries. The experiments were conducted in a completely randomized design with seven treatments and three replicates, totalling 21 experimental units. The developed films exhibited desirable characteristics, being homogeneous, thin and flexible, with thicknesses ranging from 0.084 to 0.176 mm. Yam starch-based films showed the highest maximum tensile strength (20.3 MPa), while the incorporation of CEO and chitosan resulted in a significant decrease, with values ranging from 4.09 to 7.71 MPa. Elongation at break increased from 2.37% (yam) to 49.29% (yam/CH), indicating improved flexibility. The results showed that the film containing yam starch, chitosan, and 1% CEO exhibited the best performance, with a WVP of 4.01 g·mm·m−2·day−1·kPa−1. The highest hydrophobicity was observed for the yam-based film and the yam/chitosan film. In the antimicrobial activity evaluation, Escherichia coli was susceptible to the yam/CEO2% film, while Staphylococcus aureus demonstrated sensitivity to the yam/CEO2% and yam/CEO1% films. During strawberry storage, the films containing CEO and chitosan effectively delayed fungal growth for up to 7 days compared to the control group. These results suggest that these films could be a promising alternative for food preservation, although it is important to consider the characteristic odour of CEO, which may affect the sensory acceptance of packaged foods.