## 2 Results
### GC-MS Analysis  
Table 2 shows the odor and flavor descriptors of 48 compounds present in the odor profile of roasted insects identified by SPME (GC-MS). The variety of these compounds is huge. There are compounds with fruit, nut, floral, vegetable, roasted, and many other aromas. Seventeen of them are carbonyl compounds (aldehydes and ketones), ten are alcohols, and eight are pyrazines, which are formed under the influence of high temperature in the baking of food products as a result of the Maillard reaction. Moreover, on the basis of literature data, odor threshold values (OTV) were assigned to the determined volatile compounds (Table 2). Identification of the compounds was done by Kovats indexes, and mass spectra of the compounds and NIST05 (NIST, 2011) spectral library collection (MS). The retention index standards used in this study consisted of a mixture of aliphatic hydrocarbons (C7-C20). Of the 48 odorous compounds identified in roasted insects (Table 2), furan-2-carbaldehyde (1) and benzaldehyde (16) were responsible for the burnt aroma. Pyrazines: 2,5-dimethylpyrazine (7), 2-ethyl-6-methylpyrazine (24), 2-ethyl-5-methylpyrazine (25), 2,3,5-trimethylpyrazine (26), and isobutylpyrazine (34) were responsible for roast aroma in tested insects. Nonan-2-one (38) smells like milk and maltol (42) smells like baked bread. Only 11 of them have a decisive influence on the flavor of roasted insects (Tables 3-6; complete tables in the Supplementary Material: S13 and S14). Differences between groups of two insect species, fed in two variants (PS, BC) and roasted at three different temperatures (160, 180, and 200 \({}^{\circ}\)C), were determined (Tables 3 and 4). The evaluation was based on [PERSON]'s test, \(p<0.05\). Based on this test, in almost all tested variants, statistical differentiation was found in the content of individual components, key for the formation of aroma of the product (the changes in compounds (16) and (24) were statistically not significant for insects fed with potato starch (Table 3)). The potential odor activity values (OAVs) and %OAV were calculated by dividing the concentrations of aroma compounds with their sensory thresholds (OTV) from the literature. OAVs were calculated using solid phase microextraction (SPME) with a standard addition (3-ethyl-2,5-dimethylpyrazine). A calibration curve in linear range was established. Concentration ranges of the compounds were determined based on the peak areas of compounds. The highest OAV and %OAV was noted for isobutylpyrazine (34), responsible for roast aroma (%OAV > 90% for samples roasted at lower temperatures), and 2,5-dimethylpyrazine, responsible for burnt aroma (%OAV > 20% for samples roasted at the highest temperature). It is generally assumed that the odorants with higher OAVs contribute in a stronger manner to the overall aroma. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Insect Roasting** & **W\({}_{\text{L}}\)** & **Insect Roasting** & **W\({}_{\text{L}}\)** \\
**Variants** & **W\({}_{\text{L}}\)** & **Variants** & **W\({}_{\text{L}}\)** \\ \hline TMBCI & 55.0 \(\pm\) 1.8 b & ZMBCI & 48.5 \(\pm\) 1.1 c \\ TMBCII & 54.6 \(\pm\) 0.6 b,c & ZMBCI & 48.7 \(\pm\) 0.8 c \\ TMBCIII & 57.1 \(\pm\) 0.9 a & ZMBCIII & 48.3 \(\pm\) 0.3 c \\ TMPSI & 57.3 \(\pm\) 4.3 a & ZMPSI & 51.3 \(\pm\) 1.2 a \\ TMPSII & 51.6 \(\pm\) 0.8 d & ZMPSII & 50.7 \(\pm\) 0.3 b \\ TMPSIII & 49.8 \(\pm\) 1.0 e & ZMPSIII & 51.2 \(\pm\) 0.9 a \\ \hline \hline \end{tabular} Mean values with different letters (a–e) within the same column were statistically different (\(p<0.05\)), the same letters form one homogeneous group. Values expressed as mean \(\pm\) standard deviation.  
\end{table} 
Table 1: Water loss (W\({}_{\text{L}}\)) in insects during roasting.