CHARACTERIZATION OF VOLATILE COMPOUNDS FROM ANNONA SP. FRUIT BY HS-SPME/GC-MS

Biribá is an Amazonian fruit tree of the Annonaceae family whose aromatic pulp is locally used in beverages and preserves but remains economically underutilized. This study characterized the volatile composition of biribá pulp by HS-SPME/GC-MS and evaluated the potential odor relevance of the detected compounds. Fresh fruits were collected at Assentamento Aliança, along the Amazon River, sanitized with NaOCl, and refrigerated until analysis. For headspace extraction, pulp (3 g), Milli-Q water (5 mL), and NaCl (1.5 g) were placed in 20 mL vials and heated at 40 °C under magnetic stirring. Volatiles were extracted with a PDMS SPME fiber, separated on a DB-5MS column, analyzed by GC-MS (EI, 70 eV), and tentatively identified by retention indices and mass-spectral matching. Relative peak areas (%) were obtained by peak-area normalization. Relative odor activity values (rOAVs) were calculated from relative peak areas and literature odor thresholds as rOAV = 100 × (Ci/Cref) × (Tref/Ti), where Ci and Cref are the relative peak areas of each compound and the reference compound, respectively, and Ti and Tref are their odor thresholds.¹ No internal or external standard was used for absolute quantification; the calculation therefore relies on within-variable ratios. The compound with the highest Ci/Ti ratio was selected as the reference and assigned rOAV = 100.

Twenty-eight volatile compounds were tentatively identified. α-Phellandrene was the most abundant constituent (37.5% of total peak area), followed by octanoic acid (16.0%), whereas 1,8-cineole represented only 4.7%. Despite its lower abundance, 1,8-cineole showed the highest peak-area-to-threshold ratio (threshold 1.3 ppb) and was set as the reference (rOAV = 100).² p-Cymene (6.8%; threshold 13.3 ppb) showed an rOAV of approximately 14.1,³ trans-caryophyllene (5.8%) approximately 2.5,² octanoic acid approximately 0.15,² and ethyl hexadecanoate (3.0%) approximately 0.04.² The odor relevance of α-phellandrene was interpreted cautiously because published threshold values vary with stereochemistry.⁴

Overall, chromatographic abundance alone did not predict potential odor relevance. The rOAV screening suggests that 1,8-cineole may contribute camphoraceous/spicy nuances, p-cymene citrus/green nuances depending on concentration,³ and trans-caryophyllene a secondary woody contribution. Chemically, the biribá profile contrasts with the ester-rich volatile composition reported for cherimoya (A. cherimola)⁵ and more closely resembles the terpenoid-rich profiles described for sugar apple (A. squamosa)⁶ and pond apple (A. glabra),⁷ the latter also reporting α-phellandrene among major volatiles, particularly in unripe fruit.⁷ These comparisons concern volatile composition rather than perceived aroma, which requires confirmation by sensory analysis or GC-olfactometry. The findings add new information on the odor-relevant volatile profile of biribá pulp and provide a basis for comparative studies within the Annona genus.

The authors thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (Call No. 061/2026), Universidade Federal do Amazonas (UFAM), CNPq, and FAPEAM for financial support.