Physicochemical and rheological identity of copaiba (Copaifera pubiflora Benth) oleoresin

• Copaiba oleoresin acts as a Newtonian fluid with high thermal sensitivity • Viscosity is highly temperature-dependent and displays distinct thermal hysteresis • Spectroscopy identifies high-value β-caryophyllene • Defines a new sustainable agro-industrial product for the Amazon region Copaiba oleoresin (COR) is a natural substance rich in sesquiterpenes and diterpenes, extracted from Copaifera trees. This study investigated the physicochemical and rheological properties of Copaifera pubiflora Benth oleoresin. Unlike complex fluids, COR exhibited Newtonian behavior at all temperatures tested (15 - 45°C), with viscosity remaining constant regardless of shear rate. Although the flow was stable, the material showed high thermal sensitivity (Ea = 55.25 kJ/mol) and thermal hysteresis during heating-cooling cycles. Viscoelastic measurements confirmed a predominantly liquid character (G´\G´´), and the applicability of the Cox-Merz rule validated the oleoresin as an unstructured fluid. Complementing this, Raman and NIR spectroscopy established a specific chemical fingerprint, highlighting the vibrational modes of the terpene skeletons and corroborating the presence of high-value bioactive compounds such as β-caryophyllene. Finally, color analysis indicated low lightness (L* = 25.55) and a pale yellowish hue. It is concluded that COR acts as a stable Newtonian carrier with significant thermal dependence, properties that facilitate its pumping and incorporation into agro-industrial and pharmaceutical formulations.