Enhancement of properties of seaweed-based films by fatty acid incorporation: Preservation potential for cherry tomatoes

Abstract

This study aimed to enhance the properties of seaweed (Chondrus crispus) mucilage-based films by incorporating stearic acid (SA) at concentrations of 0, 5, 10, 15, and 20 % (w/w, based on polymer weight). The fabricated films were characterized for their physicochemical, mechanical, structural, and optical properties. Furthermore, the film-forming solution (containing 0 % and 20 % SA) was used to coat cherry tomatoes, and their quality characteristics were analyzed during 12 days of storage at 10 °C. SA incorporation led to significant (p < 0.05) improvements in water vapor barrier capacity (WVP) and elasticity (EAB), with concentrations above 10% showing comparable values for both properties (p > 0.05). Films with 5 % SA showed weak oxygen barrier properties, while films with higher SA concentrations demonstrated similar performance (p > 0.05) to the control. Moreover, increasing SA concentration led to a significant decrease in light transmittance. SEM analysis revealed that SA caused layering and lipid aggregation. Furthermore, the addition of SA resulted in the formation of new bands in XRD and changes in band intensities and positions in FTIR. Coating treatments limited the changes in the total soluble solids content, pH, and titration acidity of cherry tomatoes compared to the uncoated sample. While the matrix containing 20 % SA effectively preserved the quality of the cherry tomatoes, the SA-free coating (SA0) resulted in greater weight loss and softening compared to the uncoated tomatoes. In conclusion, SA incorporation enhances the mechanical, light barrier, and structural properties of seaweed-based films, and the 20 % SA film matrix is an alternative for preserving cherry tomatoes.