Valorization of <i>Caryocar brasiliense</i> Byproducts: Microwave-Assisted Extraction of Phenolics and Material Characterization for Environmental and Bioenergy Applications

The exploitation of the pequi (<i>Caryocar brasiliense</i>) fruit generates underutilized agro-industrial residues, such as endocarps and almonds, which are rich in value-added compounds. In addition to these residues, other parts of the plant, such as the bark, also present technological potential that remains largely unexplored. This work aimed to physicochemically characterize these byproducts to evaluate their potential for environmental and industrial applications within the context of the bioeconomy and circular economy. Almonds (AM), thorny endocarp (PTE), a mixture of endocarp and almond (PTEA), and pequi tree bark (PTB) were analyzed using physicochemical, thermal, textural, and morphological characterization techniques. The results revealed significant contents of lignin (up to 34.26%), holocellulose (up to 56.25%), and lipids (up to 47.82%), as well as the presence of phenolic compounds (193.73 mg_GAE g^-1), with potential for use as natural coagulants. The materials exhibited compact morphology and predominantly mesoporous structures (2-50 nm), with specific surface areas ranging from 0.32 to 0.71 m² g^-1. Analysis of the solid residues after microwave-assisted extraction indicated structural changes that facilitate the release of bioactive compounds. PTB stood out for its lignocellulosic composition and high content of tannins and phenolic compounds, while AM showed a high lipid content, demonstrating viability for bio-oil production. These findings highlight the potential of these materials for clean and sustainable technologies, contributing to the mitigation of environmental impact and generating value in regional production chains.