The use of suitably selected parameters of ultrasound pretreatment can positively affect the content of carotenoids in dried carrots .Carotenoids content after drying process, in the most cases, increased as compared to the fresh carrots (Fig. 5). Untreated dried samples contained 20% more carotenoids than raw carrots, which may be explained by biological diversification of material or influence of heat, which causes the dissolving of the cellulose in the cell walls and releases compounds from the cell. Carrot has a hard cell wall, what stops carotenoids inside the cells. The result is that the human body is able to convert into vitamin A less than 25% of b-carotene contained in carrots. Thermal treatment causes dissolution of the cellulose, from which are built cell walls, and due to it, release of the compounds structured in cells can occur. Moreover, long time of heating may cause the increase of the carotenoids content, because of breaking up carotenoids complexes with proteins, what results in easier extraction. Furthermore, the total carotenoid content may change depending on the size of carrots and its species.