Low molecular weight volatiles in Portuguese Ficus carica varieties

Ficus carica L. is one of the earliest cultivated fruit trees. As a seasonal food, fig represents an important component of the Mediterranean diet [1]. In this work, the volatile composition of two characteristic Portuguese white varieties („Pingo de Mel“ and „Branca Tradicional“) was determined by using an HSSPME coupled to GC/FID methodology. Samples were separated into leaves, pulps and peels and were submitted to different treatments (freezing and lyophilization). The developed procedure is rapid, sensitive, reproducible, and accurate. The detection limit values for volatiles ranged between 0.007 and 166.2µg/L, and the method was precise. Recovery values were generally high. Considering its rapidity and low cost, this technique may be very useful for the quality control of fig fruits and leaves. The two analyzed varieties presented a similar profile composed by acetaldehyde, ethyl acetate, methanol, ethanol, hexanal, limonene, (E)2hexenal and octanal. Total volatiles content decreased in the following order: leaves (16593196mg/kg) > peels (10032086mg/kg) > pulps (6221087mg/kg). Methanol was the major volatile in all samples representing 55 to 87% of total identified compounds.

Acknowledgements: Fundação Calouste Gulbenkian, Branca M. Silva. Fundação para a Ciência e a Tecnologia, Andreia P. Oliveira (SFRH/BD/47620/2008).

References: 1. Oliveira, A.P. et al (2010) Food Chem. 121: 1289–1295.