###### Abstract  
Carrot (_Daucus carota_ L.) is a globally consumed root vegetable, enjoyed both raw and after thermal processing. This study aimed to evaluate the effect of different heat treatment methods (traditional boiling in water, steaming in a steel pot, steaming in a combi oven, baking in a combi oven, and the sous-vide technique) on carrot color, total phenolic and flavonoid content, phenolic and carotenoid compound profiles, and antioxidant capacity. It was found that heat treatments resulted in significant (\(p\leq 0.05\)) changes in carrot color, with reductions in lightness (L\({}^{\star}\) decreased by 19-24%), redness (a\({}^{\star}\) decreased by 52-67%), and yellowness (b\({}^{\star}\) decreased by 15-25%). Interestingly, processed carrots showed an increase in total phenolics (by 25-133%), total flavonoids (by 60-126%), and total carotenoids levels (by 16-48%) compared to raw carrots. However, specific phenolic and carotenoid compounds showed notable reductions (\(p\leq 0.05\)) after heat treatment, including vanillic acid and rutin (100% reduction after all treatments), \(\alpha\)-carotene (up to 33.3% reduction after baking), zeaxanthin (up to 33.3% reduction after baking), and 13-_cis_-\(\beta\)-carotene (up to 40.7% reduction after steaming in a combi oven). In addition, heat treatment significantly (\(p\leq 0.05\)) increased the antioxidant capacity of carrots, as determined by DPPH and ABTS assays, with increases up to 2.2-fold and 1.6-fold, respectively. The antioxidant properties of processed carrots were strongly correlated (\(p\leq 0.05\)) with total phenolic content and the levels of chlorogenic acid, \(p\)-coumaric acid, and \(\beta\)-carotene (\(r=0.86\)-0.96). boiling; baking; steaming; sous-vide; phenolic compounds; carotenoids; DPPH assay; ABTS assay  
effects [9,10]. Due to their high nutritional value and favorable storage characteristics, carrots are widely utilized in diverse culinary applications, including salads, cold dishes, cooked garnishes, and decorative elements in meals. Carrots also play an important role as an ingredient in vegetable broths and serve as a primary raw material for numerous processed products, such as frozen goods, juices, purees, dried powders, concentrates, canned foods, preserves, confections, and pickles. Furthermore, carrot pomace, which is notably rich in \(\beta\)-carotene, is often used to fortify various food products, including cakes, breads, and biscuits [11]. The preparation of carrots typically involves various thermal processing techniques, including traditional boiling, steaming, baking, and sous-vide cooking [1]. These heat treatments have a significant influence on the nutritional composition and sensory attributes of carrots, such as color, texture, and flavor [12,13]. Importantly, the concentration and bioavailability of bioactive compounds in carrots are highly dependent on the specific cooking method used [12,14,15]. For example, boiling often results in the leaching of soluble cellular components into the cooking water, as well as the degradation of antioxidants. In contrast, alternative methods like steaming, which allows for more uniform heat transfer compared to boiling, can reduce nutrient losses and better preserve the functional and nutritional properties of carrots [16]. Sous-vide cooking, a relatively modern technique, involves vacuum-sealing food in heat-resistant plastic bags and cooking it at precisely controlled, low temperatures. This method has been shown to improve flavor, texture, and nutritional quality while also extending the shelf life of prepared foods [17,18]. Numerous studies have examined the effects of thermal processing on the carotenoid composition, total phenolic content, and antioxidant properties of carrots [19-25], with particular emphasis on boiling, steaming, microwave cooking, and frying. However, limited data specifically address the impact of sous-vide cooking on carrot color [20,22,26], total phenolic content [20,22,26], phenolic compound profiles [3], and antioxidant properties [4,20,22,27].