# Black Truffle Aroma Evaluation: SPME-GC-MS vs. Sensory Experts
## 3 Results and Discussion  
### Volatile Organic Compounds Analysis via SPME-GC-MS  
A total of sixty-nine VOCs were detected using the SPME-GC-MS technique (Table 1). These molecules were previously found in _T. melanosporum_ truffles [1; 7]. Truffle maturity changes can be observed in the spore maturity [27], chemical composition [28], and bacterial community profile [29; 30] throughout the season. As indicated by [PERSON] et al. (2020) [31], metabolite levels in truffles strongly depend on the month of harvesting which is directly related to the maturity stage. Therefore, some changes are expected in the aromatic compounds as well. \begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline \multicolumn{1}{c}{**No**} & \multicolumn{1}{c}{**Name**} & \multicolumn{1}{c}{**CAS**} & \multicolumn{1}{c}{**RT**} & \multicolumn{1}{c}{**Rlexp**} & \multicolumn{1}{c}{**Rilit**} & \multicolumn{1}{c}{**1**} & \multicolumn{1}{c}{**2**} & \multicolumn{1}{c}{**3**} \\ \hline C1 & ethanol & 64-17-5 & 1.546 & \(<\)600 & 427 & 0.47 \(\pm\) 0.22 b  & 1.15 \(\pm\) 0.57 ab  & 2.11 \(\pm\) 1.38 a  \\ C2 & 2-propanone & 67-64-1 & 1.618 & \(<\)600 & 500 & 2.13 \(\pm\) 0.46 a  & 2.06 \(\pm\) 0.75 a  & 1.55 \(\pm\) 0.30 a  \\ C3 & dimethyl sulfide & 75-18-3 & 1.690 & \(<\)600 & 521 & 9.41 \(\pm\) 4.54 b  & 21.84 \(\pm\) 3.53 a  & 11.05 \(\pm\) 6.61 b  \\ C4 & methylene chloride & 75-09-2 & 1.700 & \(<\)600 & 531 & 0.31 \(\pm\) 0.61 a  & - & 0.00 \(\pm\) 0.01 a  \\ C5 & 1-propanol & 71-23-8 & 1.800 & \(<\)600 & 548 & - & - & - & - \\ C6 & propanal-2-methyl & 78-84-2 & 1.813 & \(<\)600 & 560 & 4.19 \(\pm\) 3.48 a  & 4.97 \(\pm\) 4.41 a  & 1.77 \(\pm\) 1.51 a  \\ C7 & isopropyl formate & 625-55-8 & 1.943 & \(<\)600 & 587 & - & 0.32 \(\pm\) 0.77 & - \\ C8 & butanal & 123-72-8 & 1.950 & \(<\)600 & - & - & - & - \\ C9 & 3-methyl-2- & 563-80-4 & 1.990 & \(<\)600 & - & 0.59 \(\pm\) 1.17 & - & - \\ C10 & 2-butanone & 78-93-3 & 1.993 & 600 & 602 & 0.33 \(\pm\) 0.65 b  & 4.74 \(\pm\) 1.36 a  & 3.41 \(\pm\) 1.05 a  \\ C11 & hexane & 110-54-3 & 1.995 & 600 & - & 0.82 \(\pm\) 0.99 & - & - & - \\ C12 & 2-methyl-1-propanol & 78-83-1 & 2.173 & 620 & 626 & 0.90 \(\pm\) 0.62 b  & 5.77 \(\pm\) 1.53 a  & 5.61 \(\pm\) 3.44 a  \\ C13 & butanal-3-methyl & 590-86-3 & 2.404 & 647 & 646 & 17.68 \(\pm\) 3.17 a  & 5.16 \(\pm\) 2.80 b  & 4.46 \(\pm\) 1.17 b  \\ C14 & butanal-2-methyl & 96-17-3 & 2.512 & 659 & 653 & 13.63 \(\pm\) 6.73 a  & 13.28 \(\pm\) 11.09 & & \\ C15 & 2-propanone-1- & 116-09-6 & 2.550 & 664 & - & - & - & - \\ C16 & methylpropylformate & 589-40-2 & 2.670 & 678 & - & - & 10.34 \(\pm\) 6.62 a  & 2.87 \(\pm\) 1.76 b  \\ C17 & 2-pentanone & 107-87-9 & 2.728 & 684 & 687 & 0.46 \(\pm\) 0.54 a  & - & 0.07 \(\pm\) 0.15 a  \\ C18 & pentanal & 110-62-3 & 2.730 & 685 & 704 & 0.10 \(\pm\) 0.20 a  & - & 0.20 \(\pm\) 0.40 a  \\ C19 & pyroplicateate & 109-60-4 & 3.110 & 717 & 715 & - & - & - & - \\ C20 & 3-methyl-1-butanol & 123-51-3 & 3.485 & 742 & 737 & 0.46 \(\pm\) 0.19 a  & 0.21 \(\pm\) 0.25 a  & 0.46 \(\pm\) 0.33 a  \\ C21 & 2-butanal-2-methyl & 497-03-0 & 3.636 & 753 & 749 & 0.96 \(\pm\) 0.65 & - & - & - \\ C22 & 2-methyl-1-butanol & 137-32-6 & 3.701 & 757 & 743 & 3.14 \(\pm\) 1.59 b  & 17.71 \(\pm\) 14.4 ab  & 29.25 \(\pm\) 6.40 a  \\ C23 & dimethyl-disulfide & 624-92-0 & 3.823 & 765 & 742 & 0.22 \(\pm\) 0.45 a  & 0.27 \(\pm\) 0.24 a  & 6.34 \(\pm\) 12.68 a  \\ C24 & 2-methyl-pentanal & 123-15-9 & 3.930 & 772 & - & - & - & 0.05 \(\pm\) 0.10 \\ C25 & isobutyacetate & 110-19-0 & 4.335 & 800 & 767 & - & 0.13 \(\pm\) 0.15 a  & 0.03 \(\pm\) 0.06 a  \\ C26 & hexanal & 66-25-1 & 5.050 & 817 & 801 & 12.19 \(\pm\) 8.36 a  & 1.10 \(\pm\) 0.40 b  & 1.68 \(\pm\) 0.63 b  \\ C27 & ethyllyluanoate & 7452-79-1 & 6.814 & 858 & 853 & - & 0.06 \(\pm\) 0.09 a
Different VOCs profiles were observed in truffle samples from different harvest times (Table 1). Truffles from December (time 1) showed a high content of butanal-3-methyl (17.7%), butanal-2-methyl (13.6%), hexanal (12.2%), DMS (9.4%), 1-octen-3-ol (6.7%), and 3-methylanisol (5.1%).