Potential of Annatto Seeds (Bixa orellana L.) Extract Together with Pectin-Edible Coatings: Application on Mulberry Fruits (Morus nigra L.)

<i>Morus nigra</i> L., or mulberry, is a susceptible fleshy fruit due to its high respiratory rate and low storage stability, which shortens its shelf life and makes it difficult to commercialize in natura. Edible coatings, thin membranes produced directly on the desired surface, could improve food preservation, among other properties. Annatto (<i>Bixa orellana</i> L.) seeds are natural pigments with high antioxidant activity. This work aimed to develop a pectin-based edible coating with annatto extract to increase the shelf life of fruits, using mulberries as a study model. The mulberries were randomly separated into five groups: without coating, coated with different extract concentrations (0%, 5%, and 10%), and a layer-by-layer treatment consisting of a pectin layer under a 10% extract layer. The samples were evaluated for the following parameters: titratable acidity, maturity index, mass loss, pH, soluble solids, moisture contents, and bioactive compounds. The coated group with 10% annatto extract had the best result for the maturity index (25.52), while the group with 5% showed better mass loss and moisture (37.28% and 83.66%, respectively). Herein, it was demonstrated that pectin-based edible coatings with annatto extract delay the maturation and senescence of mulberries, preserving the bioactive compounds and increasing shelf life.