Effect of citric acid and plasma activated water on the functional properties of sodium alginate for potential food packaging applications

•Cold plasma activated water (PAW) and deionized water was used in the preparation of sodium alginate (SA) solution.•SA films prepared with PAW showed better mechanical, barrier and rheological properties.•Addition of citric acid (CA) to SA reduced the tensile strength and modulus but the elongation at break improved.•A combined effect of PAW and citric acid on the functional properties of the SA films were also evaluated.•Combination of PAW and citric acid can adjust the functional properties of the SA films.•Addition of glycerol also showed remarkable change in the functional properties of the SA films in combination with PAW and citric acid.