Investigation of physio-mechanical, antioxidant and antimicrobial properties of starch- zinc oxide nanoparticles active films reinforced with Ferula gummosa Boiss essential oil

Abstract

Abstract The production of surface compounds coated with active substances has attracted a lot of attention in recent years. In this study, the physical, mechanical, antioxidant, and antimicrobial properties of starch/zinc oxide nanoparticles (ZnO NPs) composite containing various concentrations of Ferula gummosa Boiss essential oil (0.5, 1 and 1.5%) were investigated. The addition of ZnO NPs improved the thickness, and the mechanical and microbial properties, and on the other hand, reduced the water vapor permeability of the starch active film. The addition of Ferula gummosa Boiss essential oil to starch nanocomposite decreased the water vapor permeability from 6.25 to 5.63 g mm− 2 d− 1 kPa− 1, but this decrease was significant only in the concentration of 1.5% of essential oils (p < 0.05). The addition of essential oil to starch nanocomposite caused a decrease in Tensile Strength (TS) value and an increase in Elongation at Break (EB) values was obtained by adding 1.5% of Ferula gummosa Boiss essential oil to starch. The results of the antimicrobial activity of the nanocomposite showed that the pure starch film did not show any lack of growth zone. The addition of ZnO NPs to the starch matrix caused antimicrobial activity on both studied bacteria (Staphylococcus aureus, Escherichia coli). The highest antimicrobial activity was observed in the starch/ ZnO NPs film containing 1.5% essential oil with an inhibition zone of 340 mm2 on Staphylococcus aureus. Antioxidant activity increased significantly with increasing concentration of Ferula gummosa Boiss essential oil (P < 0.05). The film containing 1.5% essential oil had the highest (50.5%) antioxidant activity. In this study, the effect of starch/ ZnO NPs composite containing Ferula gummosa Boiss essential oil was also investigated in order to increase the shelf life of rainbow salmon fillets. Microbial load, lactic acid bacteria and psychrophilic bacteria of salmon fillets were reduced by coating. Coating also improved the chemical characteristics of fish fillet. In general, the starch nanocomposite containing ZnO NPs and Ferula gummosa Boiss essential oil has the ability to be used in the aquatic packaging industry.