## 3 Results and Discussion
### The Impact of PEF Pretreatment and Drying Methods on Amino Acid Profile
In terms of food, bioactive compounds exhibit some of the most crucial properties: antioxidant and antimicrobial [43; 44]. The raw material was characterized by a higher total polyphenol content (124.3 \(\pm\) 0.4 mg chlorog. acid/100 g d.m.) than dried samples. The two-factor ANOVA showed that the dose of the PEF energy intake (\(\eta^{2}\) = 0.957), the drying method (\(\eta^{2}\) = 0.818), and the interaction between the dose of the PEF energy intake and the drying method (\(\eta^{2}\) = 0.570) affected the total polyphenol content. There was no statistical difference in the TPC between the untreated samples dried by means of the CD and IR-CD methods (Figure 2). For PEF-treated samples, the noticed TPC for samples dried by means of the IR-CD method was significantly higher, regardless of the PEF energy intake. The insects subjected to the PEF at 40 kJ/kg were observed to present the highest TPC among all of the samples tested. Bioactive compounds are sensitive to high temperature [28; 45], and therefore CD-dried insects exhibited a lower TPC, contrary to insects dried by means of the IR-CD method. Similar observations were found in the study performed on yellow mealworm larvae dried by means of convective and freeze-drying methods, in which a higher TPC was found in the freeze-dried insects [46]. Furthermore, the impact of the PEF pretreatment on dried yellow mealworm larvae was observed. The differences for those samples might be referred to the electroporation phenomenon and structural damage, resulting in greater solvent penetration and the availability of bioactive compounds. The antioxidant properties of edible insects are important in terms of incorporating them into foodstuff. In general, the outcomes obtained by the ABTS and DPPH assay method resulted in different antioxidant activity, and there the ABTS values were higher than the DPPH values (Figure 3). This was true both for the fresh and the dried materials. The antioxidant properties assayed in the fresh larvae equaled 9.0 \(\pm\) 0.3 and 3.1 \(\pm\) 0.3 mg Trolox/g d.m. for ABTS and DPPH, respectively, and were characterized by higher antioxidant properties compared to dried insects. However, the two-factor analysis showed that the specific energy intake of the PEF (ABTS: \(\eta^{2}\) = 0.949, DPPH: \(\eta^{2}\) = 0.984), as well as the drying method (ABTS: \(\eta^{2}\) = 0.978, DPPH: \(\eta^{2}\) = 0.828) and the interaction between the specific energy intake of the PEF and the drying method (ABTS: \(\eta^{2}\) = 0.987,  
Figure 2: Effect of the PEF pretreatment and drying methods (CD—convective drying, IR-CD—infrared-convective drying) on total polyphenol content of yellow mealworm larvae. The different letters above columns denote statistical differences between samples (\(p<0.05\)). DPPH: \(\eta^{2}=0.977\)), affected the antioxidant activity. Furthermore, the CD samples presented a higher antioxidant capacity as compared to the IR-CD samples, except for the sample treated with the PEF at 40 kJ/kg. Based on the results, it was noted that for the PEF-treated and CD samples, the ABTS values were significantly lower than those for the untreated sample and exhibited a decreasing trend with increasing PEF energy intake (Figure 3a). In turn, the DPPH test showed a significant increase for PEF-treated insects at 20 and 40 kJ/kg (Figure 3b). For the IR-CD samples, the ABTS results depended on the dose of the PEF energy intake. The significantly higher antioxidant activity values were found for the PEF-treated sample at 5 and 40 kJ/kg. The antioxidant activity was higher for CD insects than for the IR-CD insects. This is likely connected to a lower drying time and exposure to oxygen atmosphere and temperature or due to thermal treatment, which may cause the antioxidant activity to increase [44].