CLOROFILA EXTRAÍDA DE RESÍDUO INDUSTRIAL DA ERVA-MATE (Ilex paraguaiensis) UMA POSSIBILIDADE DE ECONOMIA CIRCULAR

Abstract

Chlorophyll is the most abundant green pigment on the planet. It is unstable and decomposes naturally as can be seen in the yellowing of green tree leaves. Mate-herb is a native plant in the southern region of South America. Its plantation is present in agriculture and in the vegetal extraction of small rural enterprises in the region. The products resulting from the infusion of its leaves (chimarrão, tereré and mate tea) are part of the local culture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is proposed to be a natural pigment. The chlorophyll extraction method uses ethanol as a solvent; its structural modification leads to the obtainment of derivatives like pheophytin, Co-pheophytin, Ni-pheophytin, and Zn-pheophytin. The samples were analyzed by electronic (VIS-NIR) and vibrational (FTIR) spectroscopy; and energy dispersive X-ray fluorescence spectrometry (EDXRF). The results corroborate with the modifications made. The pigments were dispersed in synthetic enamel paint to study color stability when exposed to lighting. The chemical decomposition of the pigments was monitored by electron spectroscopy (VIS). The applied pigments were photographed for colorimetric analysis using the CIELAB color space. It was verified that Co-pheophytin and Ni-pheophytin are the most stable and presented changes in color that are more difficult to distinguish than the other compounds. Color samples from pigment photos were performed by decomposition in grayscale and the classification of the samples by the supervised Machine Learning (ML) algorithm Random Forest (RF), showing adequate accuracy for this type of matrix. The study of the use of chlorophyll as a pigment meet the need to preserve natural resources. The chlorophyll extracted from the resin presents an economically viable use for waste from small industries whose supply chain benefits family farmers, with a bias of environmental, economic and social sustainability within the circular economy.