Optimization of Drying Temperature for Preserving Bioactive Flavonoids in Cocoa (Theobroma cacao L.) Leaves: Implications for Functional Herbal Development in Chronic Disease Prevention

Abstract

The increasing demand for plant-based functional ingredients has stimulated interest in utilizing cocoa (Theobroma cacaoL.) leaves, an underutilized agricultural by-product rich in bioactive flavonoids. However, inappropriate post-harvest drying conditions may reduce the stability and recovery of these compounds. This study aimed to evaluate the effect of drying temperature on the physicochemical characteristics, extraction yield, phytochemical composition, and total flavonoid content of cocoa leaf extracts. Fresh cocoa leaves were oven-dried at 40, 50, and 60°C, extracted by maceration with 70% ethanol, and analyzed through qualitative phytochemical screening and aluminum chloride colorimetric assay using UV–Visible spectrophotometry. Statistical analysis was performed using one-way ANOVA followed by Tukey's HSD test. All drying treatments produced herbal simplicia with moisture contents below 10%, while phytochemical screening confirmed the presence of flavonoids, alkaloids, and saponins. Drying at 60°C yielded the highest extraction efficiency (8.0%) and total flavonoid content (6.402 ± 0.214%), which was significantly higher than that obtained at 40°C (p < 0.05). These findings demonstrate that controlled drying at 60°C effectively preserves flavonoids while improving extraction efficiency, providing a practical strategy for optimizing post-harvest processing of cocoa leaves. This study contributes to the valorization of cocoa leaves as a sustainable source of functional herbal ingredients with potential applications in chronic disease prevention and integrative healthcare.