Valorization of Amazonian Seed Press Cakes: Composition, Bioactives, and Food Application Potential of Cupuaçu, Pracaxi, and Murumuru co-products

The pressing of cupuaçu (Theobroma grandiflorum), pracaxi (Pentaclethra macroloba), and murumuru (Astrocaryum murumuru) seeds produces cake that retains nutritional fractions and bioactive metabolites, allowing for cascading value addition beyond the initial recovery of oil or fat. The industry currently faces difficulties in disposing of this massive volume of oilcakes in an economical and environmentally friendly manner. This study integrated bromatological composition, hydroethanolic extraction yield, total phenolics, antioxidant activity, and LC–ESI–IT3D–MS/MS profiling to compare the food potential of these three biomass sources. Protein, lipids, ash, and total soluble, and insoluble fiber were determined. EtOH:H₂O 70:30 extracts were evaluated using Folin, DPPH, ABTS, FRAP, and ORAC assays and subjected to MS/MS analysis. Pies had distinct nutritional profiles. Pracaxi pie contained 32.58 g/100g of protein, 14.31 g/100g of fat, and 42.36 g/100g of total fiber on a dry-matter basis; murumuru contained 8.25, 19.37, and 64.00 g/100g, respectively; and cupuaçu contained 16.22, 19.28, and 29.59 g/100g. The fiber was predominantly insoluble, reaching 62.83 g/100g in murumuru. Hydroethanolic extraction yield was highest in pracaxi (32.82%), followed by murumuru (16.80%) and cupuaçu (11.09%). Cupuaçu had the highest total phenolic content (13.31 mgEAG/g of dry biomass) and the highest DPPH response (185.0 µmolTE/g). Pracaxi contained 6.56 mgEAG/g and 61.8 µmolTE/g in the DPPH assay, but showed the highest responses in the ABTS (108.6 µmolTE/g), FRAP (32.8 µmolTE/g), and ORAC (73.6 µmolTE/g) assays. Murumuru exhibited 8.40 mgEAG/g and 79.2, 103.9, 10.1, and 49.8 µmolTE/g in the DPPH, ABTS, FRAP, and ORAC assays, respectively, demonstrating responses dependent on the assay mechanism. MS/MS provided additional chemical specificity. Cupuaçu and murumuru shared a peak at a nominal m/z 291 [M+H]+ associated with flavan-3-ols; in cupuaçu, the pattern is particularly consistent with catechin/epicatechin, which have already been described for the seeds and byproducts of this species. Pracaxi exhibited spermidine phenolamides: the m/z 486 precursor yielded products at m/z 310, 293, 222, and 177, consistent with the feruloyl–dihydrocaffeoyl-spermidine derivative, accompanied by features at m/z 456 and 458 from the same class. The results indicate complementary approaches: recovery of antioxidant fractions from cupuaçu, phenolamide-rich extracts associated with a protein-rich solid from pracaxi, and the utilization of murumuru as a fiber-rich matrix with an antioxidant fraction. The residual lipid content of 14–19% also supports sequential recovery prior to the use of the solids in flours, ingredients, or encapsulated systems, subject to evaluation of safety, antinutritional factors, sensory acceptance, and technological performance. It is concluded that the integrated characterization of these residues contributed to their comparison, enabling the determination of the matrices and adding new knowledge in the field of food technology, so that they can be utilized in the food formulation of a functional and sustainable ingredient. Acknowledgments: CNPq(PIBIC 2026), FAPESP(2025/11374-6) and PIDA/PRPI/USP 1602025/01