Protective coating of strawberries with cellulose nanofibers

Since shelf life of perishable foods is short, a compelling challenge is to prolong the freshness of foods with a cost-effective strategy. A perishable fruit, the strawberry, is chosen as a model perishable food and an edible film coating is applied to it using carboxymethylated cellulose nanofibers (CM-CNFs) stabilized by cationic salts. A transparent and impermeable CM-CNF film is formed at the strawberry surface using a dip coating process. The formation of the film is dependent on the electrostatic interaction between anionic CM-CNF and salt cations. Physical properties of the film are characterized and the effectiveness of edible film coating on the freshness of perishable fruit is evaluated by the measurement of weight loss, CO₂ release, firmness, total solid sugar and acidity. Cellulose nanofiber is a promising cost-effective material appropriate for use as an edible coating that contributes to the long-term storage and prolonged freshness of foods.