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Browsing by Author "Barbosa, Nathan Zafalon"

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  • Improving the debittering of Andean lupin beans using a combination of supercritical fluid extractions and natural eutectic solvents
    Publication . Barbosa, Nathan Zafalon; Martins, Mónia A.R.; Pinho, Simão; Ferreira, Olga; Sgorlon, Juliana
    Lupins are emerging as a promising source of protein for human and animal nutrition. However, they also have a high content of bitter quinolizidine alkaloids in their composition, toxic for human beings. Traditionally, the removal of these alkaloids from lupin grains involves the use of large amounts of water, resulting in contaminated wastewater. Therefore, there is a growing need to improve the debittering process of Andean lupin grains by exploring alternative and sustainable techniques that minimize the generation of toxic waste. This work investigates the combined use of supercritical carbon dioxide fluid extractions and natural based solvents to optimize the lupins debittering process. Initially, COSMO-RS was applied as a preliminary screening tool to explore the best solvents for the extraction of quinolizidine alkaloids. Butanol showed the best performance among conventional organic solvents, tetramethylammonium chloride among the ionic liquids/molten salts, and the mixtures of oxalic acid + thymol (1:1, molar ratio) among the eutectic mixtures. Subsequently, a set of candidates were selected to be evaluated as solvents on the extraction of sparteine, lupanine and 13- hydroxylupanine from Andean lupin beans. Experimental results showed that the application of solutions of lactic acid and formic acid at concentrations of 0.9 M in Et-OH/Water (8:2) mixtures, led to significantly high alkaloids extraction efficiencies under ambient conditions. Lactic acid was able to maintain its extracting efficiency even when its concentration was reduced, to around 0.45 M. Following, the best system – lactic acid 0.45 M in Et- OH/Water (8:2) – was applied as co-solvent in the supercritical carbon dioxide extraction. It was observed that, under supercritical conditions, the solvent did not maintain its efficacy, indicating that the supercritical state and the solvent to solid ratio substantially alters the solvent-alkaloid interaction. Therefore, this study showed that solutions of organic acids are promising solvent candidates for more efficient debittering processes. Future investigations should focus on optimizing these solvents under various operational conditions including supercritical, to enhance the viability of their industrial application, with the goal of facilitating the safe and sustainable use of lupin grains in human food.
    2024Master thesis Open access Show more