Análisis de la capacidad antioxidante de los extractos de microalgas Nannochloropsis oculata y posible Hapalosiphon sp. obtenidos de biomasa fresca vs liofilizada

Abstract

Microalgae have become organisms of interest in several science fields due to the diversity of components they produce, and the facility for their harvesting. Antioxidants are among the molecules present in microalgae. They are able to prevent and control oxidative stress, which is the cause of several chronic illnesses and aging. In this work, two microalgae species were analyzed in order to evaluate their antioxidant capacity: Nannochloropsis oculata, and possible Hapaloshipon sp. The techniques used for quantifying the antioxidant capacity were DPPH, FRAP & ABTS; also, the total phenolic content was measured following the Folin-Ciocalteu method. The analysis were performed in methanolic and methanol-water 50:50 %, v/v extracts of both species, each one of them obtained from fresh and lyophilized biomass. The results show that there is not a solvent or condition that allows the most efficient antioxidant extraction, but that it depends on the microalgae species. This is due to important differences between each one´s structure and cell wall composition. For Nannochloropsis oculata, the best results regarding antioxidants extraction were obtained from lyophilized biomass using methanol 100 % as solvent. In contrast, for Hapalosiphon sp. the best antioxidant extraction was found to be from fresh biomass using methanol-water 50:50 %, v/v as solvent. As for the total phenolic content, Hapalosiphon sp. fresh with methanol 100 % as solvent was the one that showed the higher amount of phenols.