Antioxidant and Antimicrobial Properties Determination of two Varieties of Malanga: White Malanga (Xanthosoma sagittifolium) and Purple Malanga (Xanthosoma violaceum) Cultivated in Ecuador

Abstract

Background and Objective: Malanga is a tuber introduced in Ecuador, rich in thiamin, riboflavin, flavonoids, protein, fibre and vitamins, ideal for a balanced diet, which today contributes enormously to the socio-economic development of some areas of the country. In this sense, the objective of this work was to know the antioxidant and antimicrobial properties of two varieties of malanga (White and purple) grown in Ecuador. Materials and Methods: For which, the extract of the two malanga varieties was obtained using two extraction methods (soxhlet and supercritical fluids "SCF"). The extracts obtained were analyzed for their antioxidant activity by the DPPH method and their antimicrobial activity by disc-plate diffusion, against strains of Escherichia coli, Salmonella, Arcobacter and Staphylococcus aureus. Gas chromatography analysis coupled to a Mass Spectrometer (to know the bioactive compounds that act) was performed. Results: After these analyses, the SCF extracts showed higher antioxidant activity. With respect to antimicrobial activity, no values greater than 8 mm in halo size were found in any of the extracts, however, it was in the S. aureus strain that there was the greater activity of SCF extracts against the pathogen. After chromatography, the most representative compounds were phthalic acid, bis (2-ethylhexyl), linoleic acid, palmitic acid, linolein, 2-mono, furfural, pyranone, all of these together act as antioxidants, anti-inflammatory and antibacterial. Conclusion: Finally, it was concluded that malanga extracts by SCF could act as inhibitors only against Gram-positive bacteria.