Influence of Extraction Methods on the Physicochemical and Biological Properties of Amazonian Beetle Larva Oil ( <i>Speciomerus ruficornis</i> )

High Resolution Image Download MS PowerPoint Slide Background and aim: The Amazonian fruit Astrocaryum vulgare (Tucumã-do-Pará) plays a central economic and cultural role on Marajó Island, where a traditional oil known as “ óleo de bicho ” (larva oil), derived from Speciomerus ruficornis larvae within the seed, is widely used in food, medicine, and cosmetics. This study compared three extraction techniques [traditional frying, mechanical pressing, and ultrasound-assisted extraction (UAE)] in terms of oil yield, physicochemical integrity, and biological effects. Experimental procedure: Larva oil was extracted by frying (180 °C), mechanical pressing, and UAE (∼50 °C) and evaluated for yield, acidity, peroxide value, and fatty acid composition. Because the raw material showed signs of prior degradation, the study also assessed the robustness of each extraction method under compromised conditions. Biological assays included MTT-based cytotoxicity and RT-qPCR analysis of p16 and p21 expression in HaCaT and B16F10 cells, with statistical analysis performed by analysis of variance/Tukey ( p < 0.05). Results and discussion: Frying produced the highest yield (45%), while UAE yielded oil with lower acidity (8.36 mg KOH/g) and peroxide value (3.97 mequiv O 2 /kg), and a balanced fatty acid profile (lauric, myristic, palmitic, and oleic acids). Cytotoxicity occurred only at the highest concentration tested (1777.35 μg/mL). Pressed oil altered p16 and p21 expression in a cell-type–dependent manner, whereas oil obtained by UAE had no significant effect on these genes, indicating no detectable cytotoxic or gene modulation effects under the tested conditions. Conclusion and implications: UAE showed the greatest preservation of the oil’s physicochemical integrity and molecular stability among the evaluated methods.