Postharvest Quality and Functional Stability of White-Fleshed Sweet Potatoes with Cactus Mucilage Coatings and Packaging

Abstract

Edible coatings based on plant-derived biopolymers are promising tools to preserve the functional quality of fresh foods. Sweet potato is considered a functional food due to its bioactive compound content, although these attributes may be compromised during postharvest storage. This study evaluated edible coatings formulated with cactus mucilage from Nopalea cochenillifera and Opuntia stricta, applied alone or combined with polypropylene packaging, on the physicochemical quality, bioactive compounds, and antioxidant activity of white-fleshed sweet potatoes. Roots were stored under refrigeration followed by shelf-life simulation. The combined use of coating and packaging reduced fresh weight loss from 22.95% in untreated roots to 1.93% in the best-performing treatment, preserved visual quality, and maintained higher total phenolic compound levels. In addition, coated roots exhibited DPPH radical scavenging activity of up to 22.9% and FRAP values up to 2.61 mmol Fe2+ kg–1 FW during storage. Optical microscopy confirmed the adhesion of the mucilage coating. While packaging primarily controlled dehydration, edible coatings contributed to the stabilization of functional attributes, supporting cactus mucilage as a sustainable strategy to enhance sweet potato functional quality.