Effect of roasting method and oil reduction on volatiles of roasted Pistacia terebinthus using direct thermal desorption-GCxGC-TOF/MS

Pistacia terebinthus fruit was roasted by either the traditional pan-roasting method or by coupled convection-microwave oven roasting (at two different settings). Cold pressing to reduce the oil content was carried out on samples either before or after the various roasting processes. Oil content of all samples was reduced to approximately 21.8g/100g by cold pressing. This allowed the grinding of the roasted fruit into powder form. The volatile compounds of these samples were investigated using direct thermal desorption coupled with gas chromatography. The main compounds found in all samples were acetic acid, limonene, α-pinene, β-pinene, 2-carene and δ-muurolene. Removal of oil was seen to decrease the number of volatile compounds found in roasted fruit (irrespective of roasting method) when compared with previous studies. Compounds specifically relating to coffee aroma (pyrazines, furans and furanones) were seen to be increased when cold pressing was carried out before the roasting process rather than afterwards.