Quantitation of bioactive compounds in citrus fruits cultivated in Taiwan

The aim of this study was to determine the levels of bioactive compounds in the edible portions of eight varieties of citrus fruits (Ponkan, Tonkan, Murcott, Wendun, Peiyou, Kumquat, Liucheng, and Lemon) cultivated in Taiwan. The amount of total polyphenol and flavonoid exceeded that of total carotenoid. Hesperidin was the major flavanone, which abounded in Liucheng and Tonkan (5.36 ± 0.145 and 4.13 ± 0.050 mg/g db, respectively). Naringin abounded in Peiyou and Wendun (1250 ± 0.82 and 2205 ± 11.1 μg/g db, respectively). Diosmin was the major flavone, and Kumquat (0.699 ± 0.021 mg/g db) and Lemon (0.323 ± 0.004 mg/g db) had the highest contents. Kaempferol was the most abundant flavanol except in Wendun, Peiyou, and Kumquat, and Murcott had the highest content (1.04 ± 0.007 mg/g db). Chlorogenic acid was the major phenolic acid, and Wendun and Lemon had the highest contents (103 ± 11.5 and 92.6 ± 8.90 μg/g db, respectively). β-Cryptoxanthin was the main carotenoid (0.764 ± 0.031–6.67 ± 0.329 μg/g db), followed by β-carotene (0.435 ± 0.016–3.77 ± 0.154 μg/g db), and these two compounds abounded in Murcott. Tonkan, Wendun, Peiyou, and Lemon had high levels of ascorbic acid. Total pectin levels ranged from 40.4 ± 1.65 to 87.3 ± 3.69 mg/g db.