# Exploring the Potential of Yellow Mealworm (_Tenebrio molitor_) Oil as a Nutraceuticalal Ingredient
## 3 Results and Discussion
### Volatile Compounds
Formation of other aliphatic aldehydes, such as pentanal, heptanal, octanal, nonanal, 2-butyl-2-octenal, and 2-hexanal, was caused by autoxidation of unsaturated 18 FAs (Table 4) [77]. These aldehydes were also previously reported in TM of larvae and obtained larvae oil [77]. It should be noted that volatile secondary and tertiary degradation products formed during lipid autoxidation are responsible for certain (off) flavor attributes in food. In the case of hexanal, its odor threshold is 4.5 ppb, and its sensory attribute is fatty, oily, grassy, tallow, and rancid but also apple and green [78; 79; 80]. Hydrocarbons were numerously represented in TM oil samples by 8 and 18 compounds belonging to aliphatic and aromatic hydrocarbons, respectively (Table 4). Their presence in TM oil samples probably resulted from lipid oxidation. Many were formed as tertiary lipid oxidation products from aldehydes due to high-temperature exposure during the technological process (75 \({}^{\circ}\)C). As stated in a previous study, some aromatic hydrocarbons, e.g., toluene and xylene, may derive from the decomposition of carotenoids, for which a substantial amount was assayed in our study (Table 4) [81]. [PERSON] et al. (2022) also detected some of the hydrocarbons of our samples: undecane, ethylbenzene, toluene, o-xylene, and p-xylene [15]. However, hydrocarbons do not significantly contribute to TM oil's aroma because many are odorless or possess high odor thresholds [16; 34]. Among the three detected alcohols, the presence of 1-octen-3-ol is worth mentioning. This compound was described to significantly affect the aroma by contributing to a characteristic mushroom aroma [16]. A substantial abundance of methyl ketones also characterized the volatile profile of TM oil samples; in total, six compounds were detected (Table 4). These compounds may be formed from unsaturated FAs and their unsaturated secondary degradation products resulting from lipid oxidation. They can be considered tertiary products of lipid oxidation [32; 81]. Ketones are odor-active; three of them: 2-butanone, 2-heptanone, and 2-decanone may contribute to the fruity, ethereal, floral, and fatty aromas of edible insects [81]. Carboxyl \begin{table}
\begin{tabular}{l c c c} \hline  & **Batch 1** & **Batch 2** & **Mean \(\pm\) SD** \\ \hline \multicolumn{3}{c}{_Terpenes_} \\ \hline \(\alpha\)-Pinene & 0.17 \(\pm\) 0.02 a & 0.55 \(\pm\) 0.02 b & 0.36 \(\pm\) 0.21 \\ \hline \(\beta\)-Pinene & 0.18 \(\pm\) 0.02 a & 0.31 \(\pm\) 0.01 b & 0.25 \(\pm\) 0.07 \\ \hline 3-Carene & 1.93 \(\pm\) 0.10 a & 2.27 \(\pm\) 0.13 b & 2.10 \(\pm\) 0.23 \\ \hline D-Limonene & 1.89 \(\pm\) 0.44 a & 3.32 \(\pm\) 0.67 b & 2.61 \(\pm\) 1.00 \\ \hline \(\alpha\)-Copaene & 0.08 \(\pm\) 0.01 a & 0.16 \(\pm\) 0.01 b & 0.12 \(\pm\) 0.05 \\ \hline \multicolumn{3}{c}{_Total_} \\ \hline \multicolumn{3}{c}{_Others_} \\ \hline
2-Pentyfuran & 1.22 \(\pm\) 0.08 a & 1.43 \(\pm\) 0.08 b & 1.32 \(\pm\) 0.14 \\ \hline Ethyl acetate & 0.53 \(\pm\) 0.07 a & 0.52 \(\pm\) 0.06 b & 0.53 \(\pm\) 0.07 \\ \hline 1H-Pyrrole & 0.17 \(\pm\) 0.03 a & 0.17 \(\pm\) 0.02 a & 0.17 \(\pm\) 0.03 \\ \hline 1H-Pyrrole, 1-butyl- & 0.25 \(\pm\) 0.01 a & 0.25 \(\pm\) 0.02 a & 0.25 \(\pm\) 0.02 \\ \hline \end{tabular}
\end{table} 
Table 4: _Cont._acids represent a higher relative abundance than ketones (6.91%); however, the aromatic contribution of this group is mainly undesirable, as their odors are described as acid, sharp, pungent, fecal, and sweaty (acetic acid, 3-methyl butanoic acid, and hexanoic acid) [81]. However, significant differences in the relative abundance of carboxylic acids between batches should be noted, which may result from differences in the physiological state of some larvae individuals as compared with the majority of larvae used in oil production [75]. Before oil extraction, larvae are subjected to a drying process. During this process, the Maillard reaction occurred.