## 3 Results and Discussion
### Phenolic Compound Profile  
Seven phenolic compounds were identified in raw carrots (Table 3): six phenolic acids (caffeic, chlorogenic, ferulic, \(m\)-coumaric, \(p\)-coumaric, and vanillic acids) and one flavonoid (rutin). Among these, chlorogenic acid was the most abundant (1026.10 \(\upmu\)g/g dw), constituting 58.4% of all detected phenolic compounds. [PERSON] et al. [28] and [PERSON] [29] identified only three phenolic acids in raw carrots: chlorogenic, caffeic, and \(p\)-coumaric acids, with chlorogenic acid being the most abundant. [PERSON] et al. [4] reported the presence of five phenolic acids (caffeic, \(p\)-coumaric, sinapic, chlorogenic, and ferulic acids) and three flavonoids (quercetin, kaempfer, and luteolin) in raw carrots, with \(p\)-coumaric acid as the dominant compound, accounting for 33.7% of the total phenolic content. In our study, all phenolic acids present in raw carrots, except for vanillic acid, were detected in heat-treated samples. Among the flavonoids, quercetin-3-O-glucose was identified in all heat-treated carrot samples, whereas quercetin was only found in carrots boiled in water. Quercetin is a flavonoid commonly found in plants in glycosylated forms, such as quercetin 3-O-glucose (Q3G), where it is bound to sugar molecules [48; 49]. Heattreatment, such as boiling, facilitates the hydrolysis of these glycosidic bonds, leading to the release of quercetin [50]. The high temperatures disrupt the bonds between the sugar moiety and the quercetin aglycone, increasing the concentration of free quercetin [51]. Moreover, heat can also break down more complex flavonoids or polyphenols, converting them into simpler molecule forms, such as quercetin [52]. In raw plant tissues, glycosylated forms like Q3G are often sequestered within the cellular matrix, making them difficult to extract or detect analytically [53]. Treatments such as boiling breakdown cell walls and the surrounding matrix release these compounds into an extractable form [54]. Unlike free quercetin, which can be degraded by prolonged or intense heating, glycosylated forms are more stable during intermediate heat treatments due to the protective effect of sugar moiety on the core structure of the flavonoid [55,56]. Chlorogenic acid remained the predominant phenolic compound in heat-treated carrots, ranging from 52.6% in sous-vide samples to 70.2% in carrots steamed in a steel pot. [PERSON] et al. [28] and [PERSON] [29] identified three phenolic acids--chlorogenic, caffeic, and \(p\)-coumaric--in steamed and dried carrots, with caffeic acid predominating while no phenolic acids were detected in boiled carrots. [PERSON] et al. [4] detected five phenolic acids (caffeic, \(p\)-coumaric, sinapic, chlorogenic, and ferulic) and three flavonoids (quercetin, kaempfer, and luteolin) in carrots steamed in a convection-steam oven, with \(p\)-coumaric acid as the most abundant. Our results indicate a general increase in the individual phenolic acid content after the heat treatment of carrots. The total phenolic acid content in raw carrots was 1718.18 \(\upmu\)g/g dw, compared to 1744.68 \(\upmu\)g/g dw in sous-vide-treated carrots, with no statistically significant difference between these samples. However, the phenolic acid content of carrots steamed in a combi oven, baked, steamed in a steel pot, and boiled in water was 2320.66 \(\upmu\)g/g dw, 2845.88 \(\upmu\)g/g dw, 3021.11 \(\upmu\)g/g dw, and 3573.25 \(\upmu\)g/g dw, respectively, significantly higher than in raw carrots. This study also observed a significant increase in the total flavonoid content after heat treatment, with the highest concentration found in traditionally boiled carrots, approximately 7.5 times higher than in raw carrots. No significant difference in flavonoid content was observed between carrots cooked using  
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