2020 Volume 19 Issue 4 Pages 391-398
In Japan, carrot cultivars are generally classified into western and oriental varieties. Recently, new intermediate cultivars were obtained by crossbreeding between these two types of cultivars. In the present study, the growth of these cultivars was also investigated to evaluate their suitability for cultivation in Aomori Prefecture, a cold region of Japan. We also determined the levels of sugars, as indicators of the eating quality, and carotenoids, as functional components, and volatile compounds, in western carrot (cv. Oranje), oriental (cv. Shinbeni-kintoki), and intermediate (cv. Kyoukurenai) cultivars. As a result, there was no significant difference in the growth of aerial parts in the three cultivars. However, the root shape in ‘Kyoukurenai’ was intermediate between western and oriental cultivars. There was no significant difference in the total content of sugars among these cultivars. However, ‘Shinbeni-kintoki’ had a smaller content of fructose but larger content of sucrose. The levels of carotenoids were significantly lower in ‘Kyoukurenai’ than in the other cultivars. In terms of the carotenoid composition, 93.4% of total carotenoids was occupied by β- and α-carotene in ‘Orange’ and 80.9% by lycopene in ‘Shinbeni-kintoki’; however, the ratio of β- and α-carotene/lycopene was almost even in ‘Kyoukurenai’. We found that the types of volatile compounds present in these cultivars were almost the same; however, the level of each compound was different. The compounds considered strongly related to the carrot-specific flavor were found to be high in ‘Shinbeni-kintoki’ and low in ‘Kyoukurenai’. On the contrary, ‘Orange’ was found to have high levels, hence a strong flavor, of sabinene and p-cymene, which are considered as “fresh green”. Based on these results, we could confirm the levels of sugars and carotenoids, as well as cultivar growth in cold regions, and could also advance knowledge on the aroma components contained in the three selected varieties.
