Extraction and evaluation of tannin from green coconut mesocarp

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.

Contemporary Developments and Emerging Trends in the Application of Spectroscopy Techniques: A Particular Reference to Coconut (Cocos nucifera L.)

“…NIR and chemometrics were applied to evaluate the cellulosic lingo components of coconut husks based on their spectral data for biofuel production and were found to be robust [ 52 ]. FTIR spectroscopy was applied for coconut husks’ chemical characterization and their adhesive capacity and application in tannin extraction [ 53 ]. The tannin-specific characteristic peaks are observed in FTIR spectral data demonstrating the husks’ utility in the production of adhesives.…”

Tannin quantification and chemical-energetic characterization of biomass residues of Bertholletia spp. and Lecythis’ spp. fruits

“…Lignocellulosic residues, such as cashew stalk bagasse, have phenolic compounds, flavonoids, tannins, sugars and ascorbic acid in their nutritional composition, in addition to their lignocellulosic composition allowing the production of xylitol and ethanol [10]. The mesocarp of the green coconut, for example, is a material with potential for the extraction of tannin and for the manufacture of composites [11]. Charcoal made from B. excelsa's biomass residues also has characteristics such as low ash content and high heating value, comparable to the charcoal produced from the wood of other species and from non-wood products too [12].…”