Quantificação Espectrofotométrica de Flavonoides em nibs de cacau (Theobroma cacao)

Abstract

Cocoa (Theobroma cacao) has great economic and social importance in Brazil, the seventh largest producer in the world and second in Latin America, with approximately 210 million tons annually. Its nibs (seed fragments) are rich in flavonoids, antioxidant phenolic compounds that neutralize free radicals and prevent diseases. This study aimed to quantify, by UV-Vis spectrophotometry, the total flavonoid content in roasted and raw cocoa pieces, comparing the efficiency of ethanol and methanol solvents in the extraction. The analysis was based on the formation of the flavonoid-AlCl₃ complex, using routine as a standard. The significant results are significantly higher in the roasted samples in both solvents. In the methanolic extract, the levels ranged from 15.1 to 28.8 mg RE/g (milligrams of Rutin Equivalents per gram of sample) for the roasted nibs, while the raw samples showed no detectable compounds (0 mg RE/g). In the ethanolic extract, the roasted samples exhibited levels between 32.2 and 35.9 mg RE/g, and the raw samples between 9.7 and 16.8 mg RE/g. It is concluded that roasting favors the degradation of flavonoids, possibly through structural modifications in the plant matrix, and that ethanol showed greater extraction efficiency. These findings reinforce the potential of roasted cocoa nibs as a source of natural antioxidants for functional food supplementation.