Stingless Bee Honeys As Natural and Edible Extraction Solvents: An Intensified Approach to Cocoa Bean Shell Valorization

This study reports the development of an intensified ultrasound-assisted extraction (UAE) method to recover bioactive compounds, specifically theobromine and caffeine, from cocoa bean shells (CBS) using stingless bee honeys (SBHs) as natural, edible, and bioactive-rich solvents. Initially, the physicochemical characterization of five SBH types, Tetragona clavipes, Tetragonisca angustula, Melipona quadrifasciata, Scaptotrigona postica, and Frieseomelitta varia, was performed. Subsequently, a Plackett–Burman design followed by a face-centered design was employed to model the effects of ultrasound power, extraction time, solvent-to-feed ratio, water addition in honey, and lactic acid concentration on the UAE-based recovery of theobromine and caffeine from CBS. Similar recovery was observed under optimal conditions (400% W, 3.5% min, 20 g/g, 20% water, and no acid) and neat honey, indicating that its intrinsic water content and acidity were sufficient for efficient extraction. Therefore, all five neat SBHs were applied under the optimized UAE conditions, leading to extracts with significantly enhanced antioxidant activity and bioactive compounds content. The sustainability of the process, measured by the Path2Green metric, showed strong alignment with green chemistry principles and the circular economy. Finally, employing edible, locally sourced, and ready-to-use solvents such as SBHs supports biorefinery strategies and promotes sustainable innovation options with socioeconomic benefits.

Sustainable cocoa shell valorization using stingless bee honey as an edible solvent integrates biodiversity conservation with green chemistry principles.