Extending the Shelf Life of Apples After Harvest Using Edible Coatings as Active Packaging—A Review

Extending the shelf life of perishable food, such as apples, and storing them in cold conditions and/or controlled atmospheres have been of great interest in the last decades. Apples are very valuable fruits with many health benefits, but during storage at ambient conditions, they ripen quickly and lose moisture, causing lower crispness or other negative effects, resulting in waste problems. There has been growing attention to protective edible coatings or active packaging films based on biopolymers and natural bioactive substances. Edible coatings and films allow for combination with functional ingredients or compounds, affecting the maintenance of the postharvest quality of fruits and vegetables. They also ensure the preservation of the sensory characteristics of food, and they can have antimicrobial or antioxidant properties. All these aspects play a significant role in the storage of apples, which can also help prevent waste, which is in line with the circular economy approach. The functionality of coatings and films is closely related to the type, content, and composition of active compounds, as well as their interaction with biopolymers. Active coatings with the addition of different functional compounds, such as plant extracts, phenolic acids, and nanoparticles, can be an alternative solution affecting the postharvest quality of apples during storage, maintaining the fruit’s stability, and thus minimising their waste. The most important issues related to the latest reports on improving the postharvest quality of apples using edible coatings incorporated with various active substances were evaluated. Agricultural conditions and factors that affect the postharvest quality of apples were described. The requirements for protective coatings for apples should be focused on low-cost materials, including waste-based resources, good miscibility, and compatibility of components. Those factors combined with the storage conditions may result in shelf life extension or retention of the postharvest quality of apples, regardless of the variety or cultivation techniques.