Potential of the stem bark of Bagassa guianensis Aubl. from sustainable forest management in the Brazilian Amazon as a raw material for biorefineries

Abstract

The bark residues have a highly available flow in the forestry industry and have been a potentially interesting resource for biorefinery. That way,for any biorefinery process, in-depth knowledge of the anatomical, chemical and physical characteristics is necessary. The bark of Bagassa guianensis Aubl trees, an important timber species of the Amazon, was studied for anatomy, density, and chemical composition, and chelating capacity of the extract, aiming at its industrial use. Anatomically, the bark is characterized by rhytidome, conducting and non-conducting phloem, laticifers, secretory cells, gelatinous and septate fibers, multiseriate rays, and the presence crystals in parenchyma cells. The summative chemical analysis is represented by 24 % total extractives, 1.97 % suberin, this suberin result aligns with what was seen in the anatomy of the bark, highlighting the small proportion of cork observed in the rhytidome, 6.6 % ash, 10.46 % lignin, and 56.97 % polysaccharides. The species presented low values for phenolic content (total phenols 8.56 mg GAE/g⁻¹ of extract, flavonoids 10.45 mg CE/g⁻¹ of extract, and condensed tannins 2.24 CE/g⁻¹ of extract), and in the mineral composition analysis, the macronutrient that stood out the most was Calcium (25.42 g/kg⁻¹), and the micronutrient was Iron (498.62 mg/kg⁻¹). The bark of Bagassa guianensis showed interesting results for chelation of the heavy metal Zinc at a concentration of 1 mg/mL⁻¹ (72 %) and at 0.10 mg/mL⁻¹ (51 %), both proving to be more efficient than the commercial chelator Ethylenediamine tetraacetic acid (EDTA), however, Copper and Iron had lower results compared to the commercial chelator EDTA. According to the characteristics presented, the bark of B. guianesis is interesting for the development of products with high added value (for example, in the in the production of pharmaceutical products, biofuel and fertilizers). The characteristics of the Bagassa guianensis bark showed promise for the material's use in the biorefinery industry.