Extraction and evaluation of tannin from green coconut mesocarp

The development of alternatives for reuse of coconut shell allows inadequate solid residues disposal reductionand provides a novelty option close to the production sites. This paper aims to evaluate the tannin extractionpotential of the green coconut mesocarp, as well as its adhesive capacity. Tannin extraction was performedwith sodium sulfite diluted in water at 0%, 1%, 5% and 8% concentrations. It was observed whichextraction resulted in better yield and characteristics to be used as an adhesive agent. The concentration ofsodium sulfite at 5% allowed higher yields of tannin extraction. When compared to phenol formaldehyde, thetannin had similar adhesive characteristics such as 153.84 cp viscosity and 54.57% solid content. For the FTIRspectroscopy analysis, dry samples of the coconut mesocarp were used. The peaks observed in the infraredspectrum of the green coconut mesocarp are characteristic of tannins found in biomass, presenting desirablechemical characteristics to be used as an adhesive agent. The coconut mesocarp is a material with potentialfor tannin extraction, making it suitable to be used in the gluing of panels.Keywords: Cocos nucifera, adhesives, residues