Evaluación de la extracción de aceite de algas Nannochloropsis oculata para su potencial aplicación en la elaboración de biodiésel

Abstract

Este estudio evaluó la extracción de aceite de la microalga Nannochloropsis Oculata mediante el método de Soxhlet, con el objetivo de mejorar las condiciones del proceso y analizar la composición del aceite obtenido. Se probaron dos métodos de ruptura de pared celular (maceración y choque térmico), tres solventes de distinta polaridad (etanol, acetona y hexano) y cuatro tiempos de extracción. El tratamiento por choque térmico presentó un rendimiento promedio de 5.23 ± 0.69 % m/m, superior al obtenido con maceración (3.35 ± 0.62 % m/m). Entre los solventes evaluados, el hexano mostró el mayor rendimiento con 4.73 ± 0.51 % m/m. El análisis cromatográfico confirmó la presencia predominante de ácidos grasos insaturados.

This study evaluated the extraction of oil from the microalgae Nannochloropsis oculata using the Soxhlet method, with the aim of improving the process conditions and analyzing the composition of the oil obtained. Two methods of cell wall disruption (maceration and thermal shock), three solvents of different polarity (ethanol, acetone, and hexane), and four extraction times were tested. The thermal shock treatment had an average yield of 5.23 ± 0.69 % 𝑤/𝑤, higher than that obtained with maceration (3.35 ± 0.62 % 𝑤/𝑤). Although the ANOVA analysis indicated that the difference was not statistically significant (𝑝 = 0.097), the trend showed greater effectiveness of thermal shock and a lower standard deviation. Among the solvents evaluated, hexane showed the highest yield with 4.73 ± 0.51 % 𝑤/𝑤, followed by ethanol (3.83 ± 0.50% 𝑤/𝑤) and acetone (2.72 ± 0.51 % 𝑤/𝑤), results consistent with Hansen's solubility parameters and with a marginal, non-significant difference (p = 0.066). In terms of extraction time, it was determined that the highest extraction occurred at 4 hours, reaching a maximum yield of 5.50 ± 0.52 % 𝑤/𝑤, after which a decrease associated with thermal degradation of lipids was observed. Chromatographic analysis (GC–MS) confirmed the predominant presence of unsaturated fatty acids, mainly oleic, linoleic, and linolenic acids.