Abstract The chemical composition of volatile compounds from Spondias tuberosa fruits were investigated at four days of maturity and from two accessions. These days were characterized through the compounds’ profiles obtained by extracting volatiles using solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). A total of 27 and 22 compounds were identified from the EPAMIG-C02 and EPAMIG-C10 accessions, respectively. The main chemical class in both accessions were the esters, aldehyde, alcohols and terpenes. The study revealed a tendency to increase the ester content and decrease the aldehyde and terpene content during four days of post-harvest ripening for the two accessions. This behavior may be monitored by five key compounds such as two esters (ethyl butanoate and ethyl hexanoate) and three aldehydes (hex-2-enal, nonanal and dec-2-enal). These compounds may be used as markers for the maturity stage for the two accessions. The Principal Components Analysis (PCA) accumulated 73.85% of the total variance in principal components 1 and 2 and showed that it is possible to differentiate the fruit ripening stages through these compounds.

Resumo Apesar da alta importância social da Spondias tuberosa Arruda, têm sido raros os estudos sobre as substâncias voláteis de frutos do umbuzeiro conhecido como umbu. Por isso, o objetivo deste estudo foi determinar as melhores condições de extração destas substâncias por microextração em fase-sólida no modo headspace (MEFS-HS) para caracterizar o perfil de voláteis na polpa dos frutos de umbu por cromatografia gasosa acoplada à espectrometria de massas (CC-EM). As condições ótimas de extração foram obtidas usando 4 g da polpa da fruta e 0,2 NaCl/polpa (m/m), mantidos por 10 min em incubação a 40 °C. A fibra de MEFS foi exposta por 20 min para a extração dos compostos e, em seguida, por 40 min para dessorção no injetor do cromatógrafo. Nestas condições, um total de 25 substâncias voláteis foram detectadas, sendo 11 delas identificadas pela primeira vez na fração volátil de polpa de umbu e 3 compostos pela primeira vez no gênero Spondias. As principais classes químicas foram os terpenos e os ésteres, os quais, juntos, representam mais de 90 % da área cromatográfica total.

Abstract despite the high social and economic importance of Spondias tuberosa Arruda, to the best of our knowledge there are very few detailed studies on the volatile compounds of this fruit popularly named umbu. Therefore, the aim of this study was to find the best extraction conditions by solid-phase microextraction in headspace mode (HS-SPME) to determine the volatile compounds from umbu fruit pulp by gas-chromatography coupled to mass spectrometry (GC-MS). The optimal conditions were obtained using 4 g of pulp and 0.2 NaCl/pulp (w/w), maintained for 10 min in incubation at 40 °C. The SPME-fiber was exposed for 20 min for extraction and then for 40 min for desorption. Thus, a total of 25 volatile compounds were detected and 16 were identified under these conditions, with 9 compounds being identified for the first time in the volatile fraction of umbu fruit pulp and two compounds were identified for the first time in the Spondias genus. The major chemical class was terpenes and esters, which together represent more than 90% of total chromatographic area.

Abstract In this study, the volatile organic compounds from Spondias tuberosa fruits of 16 accessions with different origins were extracted by solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). The volatile compounds present in the fruit from the 16 accessions were identified and submitted to multivariate analysis, with the main volatile compounds identified (from a total of 25) being: ethyl butanoate, α-pinene, myrcene/ethyl caproate, limonene, ocimene isomers, linalool/nonanal and p-menth-1-en-4-ol. The major chemical classes were terpenes (about 7-72%) and esters (about 14-72%). The relative chromatographic areas of the volatile compounds were used in Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), which accumulated 67.69% of the explained variance. The compounds classified as esters and terpenes were the main compounds responsible for forming distinct groups. The PC1 and PC2 enabled distinguishing the percentage of compounds responsible for grouping in the PCA quadrants and the HCA shows the grouping of these compounds.