Comparing carotene, anthocyanins, and terpenoid concentrations in selected carrot lines of different colors

Abstract

Plant pigments such as anthocyanins and carotenoids have been shown to be beneficial to human health. Therefore, carrot lines of different colors have been recently developed. This study aimed to characterize terpenoid, carotene, anthocyanin, and soluble solids content and antioxidant activity levels in orange, yellow, black, and purple carrots to develop new color carrot cultivars with more nutrients, health benefits, and consumer acceptance. Both individual and total terpenoid content greatly varied among breeding lines. Each line had a unique composition, and there was no general pattern between color and terpenoid content. Orange carrot roots had high levels of α-carotene, β-carotene, and total carotenoids compared with yellow. Red carrots were characterized by high lycopene content, and black carrots exhibited identical levels of lycopene content to yellow carrots. Leaf tissues contained lutein as the main carotenoid followed by β-carotene. There was no clear relationship between leaf and root carotene profiles and content. Black and purple root colors were determined by composition and amount of anthocyanin compounds, and about five major compounds were detected in this study. Total anthocyanin content was high in solid black carrots and decreased as the interior root color contained more yellow, with low and trace levels in purple and orange carrots, respectively. Soluble solid content ranged between 4.0 and 9.5 °Brix among lines. Anthocyanin content was highly correlated with antioxidant activity. Each color of carrot contained different levels of the tested compounds and may require extensive breeding to obtain desired levels.