Analysis of volatile compounds in chestnut using solid-phase microextraction coupled with GC-MS

Abstract

In this work volatile compounds of raw chestnuts (peeled and unpeeled) were evaluated. Samples of chestnuts (Castanea sativa Mill.) were obtained from the area of the Una-Sana canton (Bosnia and Herzegovina) during the seasonal harvest. Freshly harvested chestnuts were ground with a blender. A portion of chestnut was manually peeled before grinding. The samples were analyzed using solid phase microextraction (SPME) fibers in conjunction with gas chromatography/mass spectrometer (GC-MS). Compounds were identified on the basis of their retention times using the searchable EI-MS spectra library (NIST02). Volatile fraction was composed of 34 and 31 main compounds for unpeeled and peeled chestnuts respectively. Among them, 25 peaks were found in both analyzed samples. The compounds that contribute to the volatile profile of unpeeled fruit were mainly alcohols (53.99% of total areas), followed by other components (28.16%), ketones (6.70%) and esters (5.59%). The main volatile compounds found in raw peeled chestnuts were also alcohols (52.80%), followed by other components (15.47%), acids (12.40%) and ketones (11.93%). The main compounds of the volatile fraction extracted from unpeeled chestnuts samples were styrene (22.64%), ethanol (14.19%), 1-octanol (13.06%) and 3-methyl-1-butanol (5.27%), whereas ethanol (20.61%), 1-octanol (18.40%), acetic acid (11.01%), 2-pentylfuran (10.26%), 1-hexanol (7.00%) and 2-heptanone (5.86%) were identified as the main volatile components of raw peeled chestnuts. This study indicates that peeling of chestnuts affected the chemical composition of volatile compounds.