Extraction and evaluation of tannin from green coconut mesocarp

Abstract

The development of alternatives for reuse of coconut shell allows inadequate solid residues disposal reduc-tion and provides a novelty option close to the production sites. This paper aims to evaluate the tannin extrac-tion potential of the green coconut mesocarp, as well as its adhesive capacity. Tannin extraction was per-formed 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 FT-IR 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.