The objective of this work was to evaluate the effect of the biopolymers heating in alkaline and acidic solutions in the formation of nanofibers using protein concentrate from Spirulina sp. LEB 18 for potential application in food packaging field. With the highest protein concentration, the mean diameter of nanofibers was approximately 450 nm. For nanofibers developed with 5% (w.w(-1)) of protein concentrate, the peaks in FTIR spectra were observed at 1641 cm(-1) (amide I) and 1533 cm(-1) (amide II). Moreover, the increasing of protein concentration of 5-10% (w.w(-1)) enhanced the initial temperature of degradation of the nanofibers at 34 degrees C, when the poly (ethylene oxide) (PEO) was added after solution heating. The possibility of formation of uniforms nanofibers using the acidic solution with a low concentration of PEO (0.8%, w.w(-1)) shows the potential of the protein concentrate from Spirulina sp. LEB for the production of these materials. Published by Elsevier Ltd.