Formulation and biological evaluation of sodium alginate-based films blended with watercress oil: A Promising solution for combating foodborne pathogens and potential food packaging applications

The main objective of this study is to prepare sodium alginate (SA)-based biofilms incorporated with watercress oil (WCO) as an antimicrobial material for sustainable food packaging. The physicochemical, antioxidant, and antibacterial properties of the prepared bio-based films were investigated. The antioxidant activity showed a remarkable increase, with DPPH inhibition increasing from 13.6 % in WCO-0/SA (without WCO loading) to 92.6 % in WCO-5/SA (loading of WCO with a high concentration). Results also displayed the superior antimicrobial activities of WCO-5/SA against Salmonella enterica (27 mm), E. coli O157 (25 mm), Listeria monocytogenes (22 mm), and Staphylococcus aureus (20 mm),1 h, log reduction studies demonstrated a whole 6-log decrease in bacterial population counts, proving these films' abilities to combat bacterial contamination efficiently. Additionally, the findings demonstrated the potential of films as long-lasting films through the sustained release of phenolic compounds that resulted in a final content of 782 mg GAE/g DW for WCO-5/SA films. Based on these obtained data, the SA films incorporated with WCO have potential to function as active packaging materials that are environmentally friendly and may improve food safety, extend shelf-life and contribute towards sustain- ability by reducing reliance on conventional plastics.