Effect of waste Dunaliella tertiolecta biomass ethanolic extract and turmeric essential oil on properties of guar gum-based active films

The presented work focuses on the development of guar gum-based active films infused with two bio-fillers such as crude algae ethanolic extract (CAEE) and turmeric essential oil (TEO). Besides, the waste biomass of Dunaliella tertiolecta (after oil extraction) was utilized in this study to obtain CAEE. The CAEE was extracted using ultrasound-assisted technology. The influence of varying concentrations of TEO (0.5%, 1%, and 2%) at fixed CAEE concentration on the film properties including mechanical, morphological, optical, thermal, water vapor barrier, antioxidant, and antimicrobial activity was investigated. The rheological properties of the film-forming solution were also analyzed. The incorporation of CAEE and TEO improved elongation at the break value of films by ∼18% and reduced the water vapor transmission rate by ∼35%. The results of thermal stability indicated that the active films were stable at the temperature range of 25–80 °C. The increasing surface roughness, hydrophobicity, and reduction in transparency (∼32%) with UV-light blocking properties were exhibited by the developed films with increasing TEO concentration. The non-Newtonian pseudoplastic behavior was found in film-forming solutions. Furthermore, the developed active films demonstrated superior (p < 0.05) antioxidant properties and antimicrobial behavior against two known food pathogens namely, Escherichia coli and Staphylococcus aureus. Therefore, the findings of the study stipulated the synergistic effect of CAEE and TEO incorporated guar gum-based films as excellent active films. Moreover, this study could contribute to the utilization of biowaste and the development of sustainable active packaging materials that can improve food quality and safety.