## 3 Results and Discussion
### Antioxidant Capacity
Enhanced antioxidant properties following thermal processing may result from the release of antioxidants due to cell wall breakdown, the formation of thermally generated radical-scavenging compounds, the inhibition of oxidative enzymes, and the formation of new antioxidant compounds such as Maillard reaction products [63]. [PERSON] et al. [27] observed a significant decrease in DPPH activity in carrots boiled in water, while sous-vide treatment resulted in a notable increase. For certain vegetables, sous-vide processing has demonstrated a higher antioxidant potential compared to that of conventional cooking. This effect may be due to reduced cell wall degradation and nutrient leaching in sous-vide cooking due to lower temperatures and vacuum-sealing, which help to preserve antioxidant compounds, including vitamins and minerals [27]. Table 5 shows the correlation coefficients (\(r\)) between antioxidant capacity and color and content of bioactive compounds. The obtained values indicate that the antioxidant capacity of carrot samples was positively correlated with the TPC and the content of selected phenolic acids and carotenoids. It seems that the contents of chlorogenic acid, \(p\)-coumaric acid, lutein, and \(\beta\)-carotene are of great importance (statistically significant, \(p\leq 0.05\)) for the antioxidant capacity of carrot root (\(r>0.86\)). The effect of color parameters and other  
Figure 2: Antioxidant capacity of carrot root before and after different heat treatments. Data are expressed as mean value \(\pm\) standard deviation (\(n=3\)). Different letters within the DPPH and ABTS assays indicate statistically significant differences (\(p\leq 0.05\)). compounds analyzed on the antioxidant capacity was not statistically significant, although most of the \(r\) values indicated moderate or strong correlations. It was noted that there were some strong negative correlations between antioxidant capacity and color parameters as well as vanillic acid, rutin, zeaxanthin, 13-_cis_-\(\beta\)-carotene, and \(\alpha\)-carotene (\(r\) ranging from \(-0.58\) to \(-0.80\)). The strong positive correlations were observed between antioxidant capacity and FC, caffeic acid, quercetin, quercetin-3-O-glucose, and 15-_cis_-\(\beta\)-carotene, while ferulic acid and \(\beta\)-cryptoxanthin were moderately correlated with antioxidant capacity. In turn, \(m\)-coumaric acid and 9-_cis_-\(\beta\)-carotene were not affected by antioxidant capacity. Positive correlations between total phenolic content and antioxidant properties in carrot samples, as confirmed in this study, have also been documented by other researchers using DPPH [6; 61; 64; 65] and ABTS [59] assays. However, [PERSON] and [PERSON] [64] emphasized that this relationship may not accurately represent the antioxidant properties of individual phenolic compounds. Evidence from the literature suggests that the antioxidant efficacy of a specific phenolic compound is influenced by various factors, including the number of hydroxyl groups in its chemical structure. Furthermore, the proximity of the carboxylate group and hydroxyl groups on the phenolic ring in hydroxybenzoic acids negatively impacts their proton-donating capacity. Consequently, hydroxycinnamic acids generally exhibit higher antioxidant activity compared to that of their hydroxybenzoic counterparts [62; 66]. The strong correlation coefficients (r values) observed in this study between the DPPH assay results and the concentrations of \(p\)-coumaric, caffeic, chlorogenic, and ferulic acids seem to support this conclusion. Moreover, phenolic compounds can also interact synergistically, additively, or antagonistically with other bioactive compounds, which consequently affects the total antioxidant capacity [65; 66]. Consistent with the findings of the present study, [PERSON] and [PERSON] [59] reported strong positive correlation