Synergy between solvent polarity and composition for efficient extraction of bioactive compounds from pitaya

The polarity of a solvent and the characteristics of bioactive compounds are crucial factors that influence the efficiency of extraction and the composition of extracts. In this context, the use of solvent mixtures can be an effective alternative to optimize the extraction process. This study aimed to optimize the extraction of bioactive compounds (antioxidants, phenolics, and betalains) from pitaya cultivars ('Boreal Red', 'Chinese', and 'Roxa do Pará') using combinations of extracting solvents with water, namely acetone, methanol, and ethanol, both isolated and combined. To optimize, binary and ternary mixtures were tested, resulting in six formulations. The extracts were prepared with the extractor, followed by an ultrasonic bath, centrifugation, and filtration. A second extraction was performed using the filtrate supernatant. The use of solvents partly combined with water proved efficient in extracting compounds of agro-food interest, aligning with green chemistry principles and environmental protection. The formulations containing methanol, ethanol, and water, especially F5 (25% ethanol, 25% methanol, and 50% water), proved to be the most efficient for extracting antioxidant compounds, phenolics, and betalains, with high concentrations of betacyanins and betaxanthins. In all cultivars, F5 outperformed other formulations, with increases of up to 25.8% in antioxidant activity, 23.5% in total phenolics, 22.7% in betacyanins, and 27.0% in betaxanthins compared with the least effective solvents. The synergy between these solvents, due to their complementary polarities, enhanced the extraction process.