Effect of drying methods, pretreatment and storage conditions on nutritional quality and consumer acceptability of cocoyam leaves (Xanthosoma sagittifolium)

Cocoyam leaves (Xanthosoma sagittifolium) are an underutilized, nutrient-rich traditional leafy vegetable commonly consumed in Ghana. However, their high moisture content leads to rapid spoilage, limiting year-round availability and market potential. This study evaluated the effects of two drying methods (solar and freeze drying), pretreatment (blanching), storage temperature (room: 32 °C and refrigeration: 6.7 °C) and storage duration (0 and 42 days) on the nutritional, bio-functional (antioxidant activity and total phenolic content), and sensory qualities of cocoyam leaves. Using a 2 × 2 × 2 × 2 factorial design, samples were assessed for proximate composition, mineral content, antioxidant activity, total phenolics, and consumer acceptability. The results obtained were affected primarily by interactions rather than single factors. The effects of drying on protein, carbohydrate, and antioxidant activity varied with blanching and storage conditions. Phenolic and calcium contents changed over storage time, and these changes were amplified by the specific combination of drying and pretreatment and by storage temperature. Pretreatment and storage also acted jointly on fiber and zinc. Overall, the combined choice of processing steps was more influential than any individual factor. Sensory evaluation revealed no significant differences (p > 0.05) in color, aroma, texture, or overall acceptability across treatments. These results demonstrate that appropriate drying and storage techniques can extend shelf life and preserve the nutritional and functional properties of cocoyam leaves, supporting their integration into value-added food systems and improving food and nutrition security in Ghana.