Effects of ultrasound pre-treatment on the physicochemical, structural, thermal, and functional properties of cacauí (Theobroma speciosum Willd. ex Spreng.)

Abstract The study evaluated the effect of ultrasound pre-treatment on the physicochemical, structural, and functional properties of Theobroma speciosum Willd. ex Spreng (cacauí) seed powder, focusing on the release of bioactive compounds. The proximate composition indicated low moisture content (2.31–3.98%) and high levels of lipids (25.94–28.92%) and carbohydrates (50.31–54.37%), as well as moderate amounts of proteins (14.69–16.25%) and ash (1.78–2.85%), demonstrating high nutritional value. FTIR analysis confirmed the presence of functional groups typical of lipids, proteins, and polysaccharides, showing that ultrasound promoted changes in intermolecular interactions without compromising the chemical integrity of the matrix. The identification of theacrine highlighted the potential of cacauí as a source of bioactive alkaloids of nutraceutical interest. SEM micrographs showed increased roughness, porosity, and particle fragmentation with increasing ultrasound amplitude and time, indicating cell wall disruption and greater exposure of intracellular compounds. Thermogravimetric analysis revealed a thermal profile typical of lignocellulosic biomass, with small variations in thermal stability after treatment. Antioxidant assays (DPPH, ABTS, and FRAP) and total phenolic content showed a significant increase in antioxidant activity, especially under the C70/12 condition, indicating that acoustic cavitation favors the release of phenolic compounds. The mineral profile showed predominance of K, P, Mg, and Ca, as well as Fe, Zn, Mn, and Cu, reinforcing the nutritional potential of cacauí as a source of essential minerals and a functional ingredient.