The antioxidant activity of nanoemulsions based on lipids and peptides from Spirulina sp. LEB18

Nanoemulsions present several advantages over macroemulsions, since they guarantee characteristics of compounds such as greater bioavailability, kinetic stability, besides facilitating the transport of compounds of interest. The incorporation of biopeptides into nanoemulsions makes its applicability viable in several areas such as cosmetics, pharmaceuticals and foods. Linked to this, the use of microalgal lipids rich in polyunsaturated fatty acids such as the oil phase in a nanoemulsion, gets attractive when one consults data of its benefits to human health. The objective of this study was to develop lipid-based nanoemulsions extracted from de microalga Spirulina sp. LEB18, with incorporation of biopeptides obtained from this same microalga, evaluating its nanoemulsions antioxidant activity. Distilled water and Tween® 80 surfactant were used as the aqueous phase and as microalgal lipid oil phase, a solvent mixture of chloroform-methanol (2:1) and biopeptides was used. The nanoemulsions presented mean droplet diameter at the range of 222.9 ± 3.4 to 466.9 ± 5.3 nm, remaining constant over the period analyzed (14 d). Moreover, all nanoemulsions presented antioxidant activity and electrostatic stability, having zeta potential values below −30 mV. It was also possible to observe that lipids from Spirulina sp. LEB18 presented stabilizing capacity, acting as biosurfactant.