Extraction and evaluation of tannin from green coconut mesocarp

Fernanda Lago Morbeck,Roberto Carlos Costa Lelis,Bruno Couto Da Silva,Gregório Mateus Santana,Danielle Affonso Sampaio,Maria Vanessa Egger Schueler,Rayssa De Medeiros Morais,Wanessa Aparecida Santos

doi:10.1590/s1517-707620190003.0748

Fernanda Lago Morbeck, Roberto Carlos Costa Lelis + Show 6 more

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https://doi.org/10.1590/s1517-707620190003.0748

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Abstract

ABSTRACT 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 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.

Highlights

Renewable resources can be used to replace phenolic compounds from the petrochemical sector
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
3.1 Chemical analysis of mesocarp by Fourier transform infrared spectroscopy (FT-IR) Figure 1 shows the infrared spectrum of the green coconut mesocarp tannin

Summary

Introduction

Renewable resources can be used to replace phenolic compounds from the petrochemical sector Examples of such resources are lignin residue derived from pulping, tannins from bark, wood of some forest species and products derived from the carbonization of forest biomass [1]. MORBECK, F.L.; LELIS, R.C.C.; SCHUELER, M.V.E., et al revista Matéria, v.24, n.3, 2019. Tannins are polyphenols of high molecular weight, found in several parts of plants, bark, root, wood and fruits. They react with formaldehyde and may be used as source of adhesive, while mitigating issues with agricultural market residues [1]

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