Estudo da composição química, solubilização e composição fenólica da lignina Kraft para aplicações cosméticas

Abstract

Lignin has been suggested as a promising candidate for cosmetic applications due to its remarkable potential to absorb ultraviolet rays and its distinct antioxidant activity. As a by-product generated from black liquor, Kraft lignin can be reused, providing an opportunity for the companies that generate it to align environmental issues with the economy. This study aimed to evaluate the performance of Kraft lignin, generated by a pulp and paper company, from eucalyptus and pine species, and, based on the analysis, its use in other products was proposed, such as in the cosmetics area. In order to understand the bioactive potential of lignin, an exploratory test was carried out on the different solubilities of the material with variation in proportion in relation to the solvent, types of solvents, extraction time and temperature. The content of phenolic compounds was performed using the Folin-Ciocalteu method. The solvent that solubilized the highest concentration of phenolics was ethylene glycol, for an extraction period of 120 minutes, at 40° and in a proportion of 0.2g of lignin in 10 ml of solvent, reaching 339 mgEAG/g lignin. In addition to the FC test, the lignin was analyzed using the Scanning Electron Microscope with Energy Dispersive Spectroscopy (SEM-EDS) to determine its morphology and elemental composition, showing irregular structures with spherical particles. Its composition showed high amounts of carbon and oxygen in its structure and less than 1% of sulfur. The tests showed a lignin that has a high phenolic composition and low amount of impurities, which favors its study for use as an active ingredient in cosmetics.