Active packaging and increasing shelf life of virgin olive oil using biodegradable film based on polyvinyl alcohol modified with silver chloride nanoparticles and spirulina

In this study, biodegradable film was prepared from polyvinyl alcohol. Silver chloride nanoparticles and spirulina algae powder were used to modify the physicochemical structure and create antioxidant activity in the film. The surface morphology of the film was investigated. Polyvinyl alcohol film and its composites were used for packaging virgin olive oil. D-optimal design was used to investigate the effect of packaging type and storage time on the chemical, color and sensory characteristics of the oil. Chemical characteristics (acidity, peroxide value, refractive index and total phenol), sensory and color characteristics were investigated. The response surface method was used to investigate the effect of independent variables on the oil as well as the created mathematical models. The obtained results showed that in polyvinyl alcohol film modified with silver chloride particles and polyvinyl alcohol modified with silver chloride and spirulina particles, the presence of these particles on the surface of the film was completely evident. The results of the chemical, sensory and color analysis of the oil showed that the chemical, sensory and color quality of the oil decreased with the increase in the storage time of the oil in all packages. Peroxide value as the most important indicator of the quality of oils in normal packaging increased from 1 to 7 (mEq O2/Kg oil) during 30 days of storage, while in oil packaged with polyvinyl alcohol modified with silver chloride and spirulina algae, this increase was from 1 to 2 (mEq O2/Kg oil). In general, oils packaged with polyvinyl alcohol modified with silver chloride and spirulina algae showed the least quality changes compared to normal packaging, which indicates the ability of these films to control the quality and increase the shelf life of virgin olive oil.