Evaluation of the volatile profile by SPME and GC-MS produced during solid-state fermentation of pineapple crown

Pineapple crown (PC) is a by-product of pineapple processing that might encounter technological applications due to the presence of antioxidants, fibers, enzymes, and other compounds, besides being a rich substrate to support microbial growth in biotechnological processes. This work aimed to compare the profile of volatile compounds (VC) in raw and autoclaved PCs before and after the growth of Fusarium oxysporum for 14 days (Solid-State Fermentation). The autoclaved (APC) and fermented PC (FPC) samples were transferred to vials and incubated in a temperature-controlled (50 °C) water bath for VC extraction using the solid phase microextraction (SPME) technique with two different microfibers (Gf: DVB/CAR/PDMS; 50/30 μm and Bf: CAR/PDMS; 75 μm). The VC were absorbed into the microfibers for 3 min, then desorbed on the GC–MS (Agilent 7820A) injection port (250 °C). The VC were separated by an HP-5-MS column using Helium as a carrier gas. The ionization of electrons and mass range were adjusted as +70 eV and 35–450 m/z. Compound identification was performed with NIST 2014 Library. 78 VC were identified, where the Bf fiber adsorbed more VC than the Gf. The area (%) of some compounds decreased with Gf fiber. Terpenes were the most frequently detected class of compounds (27 VC). The number of VC decreased in the APC (20) and FPC (19) samples. Only limonene was found in all samples, however, in different concentrations. The main VC in PC (57.66%) and FPC (13.04%) was limonene, while in APC it was furfural (30.49%) and limonene (30.20%). The increase in temperature during autoclaving and fermentation influenced the quantity and profile VC. This is the first report of VC present in PC. The diversity of VC may potentially be used for aroma production by direct extraction or as a substrate for microbial biotransformation, yielding novel aroma compounds.