Extraction and evaluation of tannin from green coconut mesocarp

Résumé

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