RESUMO
The stability of antioxidant protein hydrolysates from Spirulina sp. LEB 18 was evaluated under food processing conditions and after in vitro digestion. Protein hydrolysates with degrees of hydrolysis of 50.6% and 60% were obtained after 90 and 120 min of reaction, respectively, with Protemax 580 L. The results indicated that the antioxidant activity of protein hydrolysates was maintained following application of heat treatment (- 18 °C, 63 °C, and 100 °C). Moreover, the ability of protein hydrolysates to inhibit the 2,2-diphenyl-1-picrylhydrazyl radical was increased by nearly 25% upon exposure to acidified media (pH 4 and pH 6). In general terms, the protein hydrolysates were bioavailable after digestion with pepsin and pancreatin. This study supports the incorporation of bioactive peptides from microalgae into functional foods by demonstrating the maintenance of their biological activities in the face of food processing conditions and gastrointestinal digestion.
RESUMO
The objective of this work was to produce nanoparticles containing bioactive peptides obtained by the enzymatic hydrolysis reaction of microalgal biomass. The hydrolysates were purified by vacuum filtration with membranes of different sizes and by vertical column membranes. After each step, an antioxidant activity test was conducted. The nanoparticles were developed by nanoatomization, with the size and morphology of the particles analyzed by scanning electron microscopy (SEM). The microalgae hydrolysates showed high antioxidant activity compared to non-hydrolyzed biomass. The nanoatomization of bioactive peptides caused no significant reduction in antioxidant activity, with maximum reductions of 15.0 and 17.4% by DPPH assay and 2.5 and 3.8% determined by reducing power assay for Spirulina LEB 18 and Chlorella pyrenoidosa, respectively, with no reduction in the ABTS values. Nanoparticles with sizes ranging from 1418 nm and 72108 were obtained for the Spirulina and Chlorella hydrolysates, respectively.
