Comparison between essential oils and supercritical extracts into chitosan-based edible coatings on strawberry quality during cold storage

Plant extracts are being studied in the development of novel edible food coatings. The antioxidant and antimicrobial compounds that naturally occur in some plants are the key substances that contribute to preserving food quality. Besides the plant material, the method utilized to produce the extract influences its chemical and preservative characteristics. In general, hydrodistillation produce plant products (essential oils) that are well recognized for containing high concentration of antioxidant or antimicrobial volatile compounds. Supercritical fluid technology produces high quality bioactive extracts with higher yield but lower concentration of volatile compounds, in comparison with hydrodistillation. In this work, six different natural extracts of five different plants were produced by hydrodistillation and supercritical fluid extraction, and their antioxidant and antimicrobial activities were compared. The most active extracts were used to produce chitosan-based edible coatings with the aim of assessing the effect of essential oils versus supercritical extracts on the preservation of strawberries.