Atividades antioxidante, antibacteriana, teor de tocoferóis e ácidos graxos em diferentes variedades de abacate

Abstract

Avocado is a tropical fruit with attractive nutritional characteristics, highlighting the content of antioxidants and bioactive compounds, such as tocopherols and the high amount of monounsaturated fatty acids. The present work had as main objectives to characterize the bark, pulp and seed extracts of four varieties of avocado (Quintal, Fortuna, Margarida and Hass) in terms of their antioxidant, antibacterial and toxicity properties. Besides the determination of its composition centesimal, content of fatty acids and tocopherols from the lipids extracted from the husks, pulps and seeds. The antioxidant activity was determined by the methods of DPPH, ABTS and FRAP and supplemented with phenolic compounds and flavonoids. The antibacterial activity was tested against foodborne pathogens by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. Toxicity was evaluated against Artemia salina and hemolytic activity. Total lipids were extracted by the method of Bligh and Dyer, and for analysis of fatty acid composition, the fatty acid methyl esters were separated using a gas chromatograph. For the determination of the tocopherol isomers, a high performance liquid chromatograph was used and quantified by external calibration. The ethanolic extract of the peel of the Quintal variety showed the highest antioxidant and antimicrobial activity. This same extract had no toxic effect in the preliminary tests performed. Avocado pulps showed high concentrations of monounsaturated fatty acids, especially oleic acid. There was also a considerable amount of tocopherols in the peels and seeds of the avocado.