“…The quantification of volatile compounds was calculated using the peak area ratio to the internal standard, and it was multiplied by the concentration of the internal standard. The semi-qualification of aldehydes, esters, ketone, phenols and Furan(one)s was calculated by using 2-methyl-3-heptanone as the internal standard, whereas acids, alcohols and pyrazines were calculated by using 4-nonanol as the internal standard [16]. Semi-quantification was calculated using the following formula: UC conc.…”