Avaliação da capacidade antioxidante e compostos fenólicos em três sementes oleaginosas: castanha-do-brasil, castanha de caju e noz pecã
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Data
2018-06-25
Autores
Souza, Ivânia Santos de
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Universidade Estadual Paulista (Unesp)
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Objetivos: Determinar a composição centesimal da castanha-do-brasil, castanha de caju crua e da noz pecã, estabelecer as melhores condições de extração dos compostos fenólicos totais, avaliar sua capacidade antioxidante in vitro e identificar os compostos fenólicos presentes. Métodos: Foi realizada a composição centesimal utilizando-se o método da AOAC e Bligh & Dyer para os lipídeos. A extração dos compostos fenólicos foi otimizada com os fatores solvente (%) (acetona e etanol) e tempo de extração utilizando-se Planejamento Composto Central. O teor de compostos fenólicos totais foi estimado utilizando-se o método de Folin-Ciocalteu. A capacidade antioxidante foi verificada através do ensaio do ABTS e DPPH. O perfil dos compostos fenólicos foi analisado por HPLC. Resultados: Além dos lipídeos, as sementes oleaginosas apresentaram as proteínas como componente majoritário. Na otimização da extração, a porcentagem de solvente e o tempo de extração mais eficiente foi etanol 55,56% e 15,86 min., etanol 70% e 44,14 min., acetona 66,39% e 28,02 min. para a castanha-do-brasil, castanha de caju crua e noz pecã, respectivamente. Nas análises de compostos fenólicos totais e de capacidade antioxidante a noz pecã apresentou valor bem superior à castanha-do-brasil e castanha de caju crua, sendo que essas diferiram estatisticamente entre si apenas no ensaio do DPPH. Os compostos fenólicos e a capacidade antioxidante demonstraram correlação positiva e significativa. Os compostos fenólicos identificados foram o ácido gálico, presente nas três sementes oleaginosas; a catequina na castanha-do-brasil e na castanha de caju crua e a epicatequina na castanha de caju crua. Conclusão: A polaridade contribuiu de forma significativa para a eficiência da extração dos compostos fenólicos. A noz pecã apresentou maior quantidade de compostos fenólicos e de capacidade antioxidante. O ácido gálico foi identificado em todas as sementes oleaginosas analisadas.
Objectives: To determine the centesimal composition of the Brazil nuts, cashew nuts and pecan nuts, the best phenolic compounds extraction conditions, to evaluate the antioxidant capacity in vitro and to identify the phenolic compounds profile. Methods: Centesimal composition was performed using the AOAC method and Bligh & Dyer for the lipids. Extraction of the phenolic compounds was optimized with the factors solvent (%) (acetone and ethanol) and extraction time using Central Composite Design. Total phenolic compounds were estimated using the Folin-Ciocalteu method. Antioxidant capacity was verified through the ABTS and DPPH assay. Individual phenolic compounds were analyzed by HPLC. Results: In addition to the lipids, nuts showed the proteins as major component. In the optimization of the extraction, the most efficient solvent and extraction time were ethanol 55.56% and 15.86 min., ethanol 70% and 44.14 min., acetone 66.39% and 28.02 min. for Brazil nuts, raw cashew nuts and pecan nuts, respectively. Total phenolic compounds and antioxidant capacity of pecan nuts presented a much higher value than Brazil nuts and raw cashew nuts, which differed statistically only in the DPPH assay. Phenolic compounds identified were gallic acid, present in all nuts; catechin in Brazil nuts and raw cashew nuts and epicatechin in raw cashew nuts. Conclusion: Polarity contributed significantly for extraction efficiency of the phenolic compounds. Pecan nuts showed the highest amount of phenolic compounds and antioxidant capacity. Gallic acid was identified in all nuts analyzed.
Objectives: To determine the centesimal composition of the Brazil nuts, cashew nuts and pecan nuts, the best phenolic compounds extraction conditions, to evaluate the antioxidant capacity in vitro and to identify the phenolic compounds profile. Methods: Centesimal composition was performed using the AOAC method and Bligh & Dyer for the lipids. Extraction of the phenolic compounds was optimized with the factors solvent (%) (acetone and ethanol) and extraction time using Central Composite Design. Total phenolic compounds were estimated using the Folin-Ciocalteu method. Antioxidant capacity was verified through the ABTS and DPPH assay. Individual phenolic compounds were analyzed by HPLC. Results: In addition to the lipids, nuts showed the proteins as major component. In the optimization of the extraction, the most efficient solvent and extraction time were ethanol 55.56% and 15.86 min., ethanol 70% and 44.14 min., acetone 66.39% and 28.02 min. for Brazil nuts, raw cashew nuts and pecan nuts, respectively. Total phenolic compounds and antioxidant capacity of pecan nuts presented a much higher value than Brazil nuts and raw cashew nuts, which differed statistically only in the DPPH assay. Phenolic compounds identified were gallic acid, present in all nuts; catechin in Brazil nuts and raw cashew nuts and epicatechin in raw cashew nuts. Conclusion: Polarity contributed significantly for extraction efficiency of the phenolic compounds. Pecan nuts showed the highest amount of phenolic compounds and antioxidant capacity. Gallic acid was identified in all nuts analyzed.
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Semente, Compostos fenólicos, Ação antioxidante, Castanha, Noz, Seed, Phenolic compounds, Antioxidant, Nuts