The Use of Bioactive Edible Coatings Based on Pectin and Phenolic Acids for Enhancing Quality Attributes of Golden Delicious Apples During Storage

This research study investigated the effect of edible coatings made from apple pectin, incorporating caffeic and protocatechuic acids, on the quality attributes of Golden Delicious apples during 28 days of storage at ambient conditions. The study evaluated the rheological properties of the coating solutions, the release of phenolic acids from the edible films, and various quality characteristics of the apples. These characteristics included weight loss, colour, total soluble solids, total titratable acidity, pH, firmness, respiration rate, ripeness level, and sensory analysis. The results showed that all coating solutions exhibited non-Newtonian, shear-thinning flow behaviour, with the sample containing protocatechuic acid demonstrating a decrease in apparent viscosity. Additionally, both phenolic acids were released rapidly from the film into a 96% ethanol medium. The study found that bioactive edible coatings, both with and without phenolic acids, were significantly effective in reducing weight loss, colour changes, firmness, and ripening of apples during storage. The total soluble solids were higher in control apples (14.95 ± 0.48 °Brix at 28 days) compared to the coated samples (13.52–13.53 °Brix at 28 days), indicating that the control apples were riper and contained a higher amount of sugars. Ethylene production decreased after 4 weeks of storage, from 60.40 ppm for the apples before storage to 23.55–25.70 ppm for the coated samples, and only to 52.75 ppm for the control apples. Overall, this study confirmed that the use of developed bioactive coatings extends the shelf life of apples by preserving their quality and sensory attributes during storage.