In order to increase the shelf life and maintain the quality and stability of the biological compounds with antioxidant activity present in Castilla blackberry fruits, a sodium alginate-based edible crosslinked coating was applied, and the fruits were packed in two different plastic containers and stored under refrigeration (3 ± 1 °C). Total antioxidant capacity and its relationship to physicochemical variables such as pH, Brix, and acidity were evaluated in six treatments: uncoated blackberry stored in a macroperforated container (T1) and thermosealed container (T2), without crosslinked coating in a macroperforated container (T3) and thermosealed container (T4), with crosslinked coating (calcium ions) packed in macroperforated container (T5) and thermosealed container (T6). The results indicated that factors such as gas permeability in the coatings, the packaging used, and physicochemical parameters significantly affected the fruit total antioxidant capacity, with the highest level in T1 (0.22 µgEAA/ml) at the end of the essay, which is related to the lowest levels of pH and direct exposure to air. On the other hand, the lowest value was obtained in T6 (0.16 µgEAA/ml) due to the crosslinked coating, packaging in the thermosealed container, and higher pH value. Variations in acidity, Brix, and pH indicate the presence of degenerative processes in the crosslinked coating treatments, which limited the physicochemical changes.